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1
Q

what are the 6 kingdoms and give a feature of each

A
  1. monera (prokaryotes)
  2. protista (eukaryotic, single celled)
  3. fungi (heterotrophic, walls of chitin)
  4. plantae (photosynthetic, autotrophic)
  5. animalia (heterotrophic)
  6. archaebacteria (anaerobic)
2
Q

how many phyla of animals are there believed to be?

A

40

3
Q

what is the order of the geographical periods starting from quaternary?

A

quaternary, tertiary, cretaceous, jurassic, triassic, permian, carboniferous, devonian, silurian, ordovician, cambrian, ediacaran, precambrian

4
Q

when (period) were the earliest animal and prokaryote fossils?

A

precambrian

animal- 1700mya

5
Q

when was there glaciation in the southern hemisphere?

A

carboniferous

6
Q

what environmental events occured in the Quaternary?

A

cooler glacial conditions, south polar ice cap forms, human evolution in last 5-3 my

7
Q

what is the burgess shale

A

soft bodied fossil bearing deposit (fossils from cambrian explosion) discovered by Walcott in 1909
- mostly benthic forms

8
Q

what 2 physical factors are important in animal evolution?

A

climate change and continental drift

9
Q

describe glaciation

A

climate change causes glaciation and it leads to isolation and separation of pops as they differentiate genetically. ice disappears and distinct species and populations appear.
hybrid zones where previously isolated species meet

10
Q

describe continental drift

A

Alfred Wegener proposed the idea in 1915. land masses once joined into supercontinent pangea but masses separated by continental drift due to plate tectonics. earths crust is comprised of 7 large plates floating on the mantle

11
Q

a) what 4 problems must animals solve to survive?

b) what must the body design be correlated with to meet these?

A
a)
1. getting food and O2
2. maintain salt and water balance
3. remove waste
4. reproduction
b)
1. environment
2. size of animal
3. mode of existence
4. genome constraints
12
Q

what % earths surface marine and roughly what % vertebrates are fish?

A

71%

50%

13
Q

which 2 zones are within the neritic zone- give depths and features

A
  1. eulittoral (between rise and fall of tide- animals adapted to exposure like barnacles)
  2. continental shelf/sublittoral (150-200m, sunlight benefits algae, coral reef is symbiotic relationship between poly and algae
14
Q

what 8 zones are within the oceanic zone and give depths?

A
  1. continental slope (shore-3000+m)
  2. epipelagic (200m)
  3. mesopelagic (300-1000m)
  4. bathypelagic (1000-2000m)
  5. abyssopelagic (2000-3000m)
  6. hadalpelagic (3000+m)
  7. abyssal plain (3000-5000m)
  8. mariana trench (11,000m)
15
Q

whats the difference between photic and aphotic zones?

A

light can penetrate photic zones and it is anywhere up to 200m deep. aphotic zone has increased pressure, decreased light and temp, more scarce food source, different feeding mechanisms

16
Q

give an example of an animal that can survive in the eulittoral or sublittoral zone

A

epaulette shark- when tide out lives in eulittoral zone, when low O2 can shut down its body but keep the flow to the brain and can use its fins to move in the pools

17
Q

give 2 examples of deep sea animals

A

anglerfish- light produced by bacteria help it survive by drawing in prey.

harp sponge- usually filter feeders but are carnivorous in deep sea

18
Q

define

a) pelagic
b) benthic
c) errant
d) sessile
e) sedentary

A

a) suspended or swimming
b) bottom
c) mobile
d) attached
e) unattached, immobile

19
Q

what is coastal upwelling?

A

as the sea moves there is water exchange between higher and lower waters and nutrients move from the bottom to the top

20
Q

give 11 advantages of the ocean

A
  1. space- high productivity (28 x 10*9 c/yr)
  2. biomass decreases from shoreline to open ocean
  3. biomass decreases towards tropics (tropical waters have less temp change so less movement)
  4. salinity 3.4-3.6%
  5. oxygen
  6. water movement constant
  7. deep ocean currents- saltier water sinks moving slowly along bottom
  8. iso-osmotic with body tissue fluids of many animals (osmoconformers, invertebrates will retain solutes to increase body conc)
  9. buoyancy
  10. fertilisation and development (external)
  11. waste as ammonia
21
Q

give 4 brief features of a marine environment

A
  • constant salinity, temp, O2
  • provides support
  • medium for fertilisation
  • waste as ammonia
22
Q

give 6 brief features of a freshwater environment

A
  • less constant temp, O2, velocity, volume
  • osmotic regulation needed
  • support
  • eggs retained by parent
  • direct development
  • waste as ammonia
23
Q

give 4 brief features of a estuarine environment

A
  • seasonal variations
  • fresh and sea water mix
  • support
  • waste as ammonia
24
Q

give 6 brief features of a terrestrial environment

A
  • daily and seasonal temp extremes
  • O2 constant and uptake needs moist surface
  • can suffer water loss
  • no support
  • internal fertilisation
  • waste as urea/uric acid
25
Q

what generally happens to the lake condition in summer?

A

epilimnion (O2 rich) seperated from hypolimnion (O2 poor) by broad zone thermocline in summer due to rapid change in temp and O2 with increasing depth

26
Q

what happens as body size increases?

A

SA:V decreases and mechanisms other than diffusion are needed

27
Q

are free moving organisms often bilaterally or radially symmetrical?

A

bilaterally

28
Q

give an example of a constraint of the genome

A

there are limitations imposed by the ancestral design which are controlled by the animals genetic makeup- for example molluscs have the same basic body plan that is modified in different ways

29
Q

give 6 features of protozoans

A
  • single celled
  • eukaryotic
  • motile
  • heterotrophic
  • have pellicle (cytoskeleton and cell membrane)
  • have test (hardened outer structure)
30
Q

describe locomotion of protozoans

A
  • flagella to propel
  • cilia beating in metachronal waves
  • pseudopodia
31
Q

in what 3 ways is food acquired by protozoans?

and what digests the contents?

A
  1. pinocytosis (high conc food particles outside cell and low inside- pinched into vesicle)
  2. receptor mediated endocytosis (receptors on cell membrane bind with molecules, engulfed into vesicle)
  3. phagocytosis (large food particles bind to receptors and form vesicle)

lysosomes digest contents

32
Q

how did the protozoans originate?

A

the endosymbiont theory- occured to utilise O2 as levels increased in atmosphere:

  1. plasma membrane of ancestral prokaryote infolds
  2. cell with nucleus and endomembrane systems engulfs aerobic heterotrophic prokaryotes by endocytosis
  3. ancestral heterotrophic eukaryote formed with mitochondrion
33
Q

what are the 4 types of protozoan?

A

amoeboid
apicomplexans
flagellates
ciliates

34
Q

what are the 2 types of pseudopodia?

A

lobopodia (more rounded)

filopodia (spikey)

35
Q

describe amoeboids

A

asexual, move by pseudopodia, free- living (amoeba) and parasitic (E.histolytica)

36
Q

describe the life cycle of amoeboid E.histolytica

A
  • usually from faeces or uncooked food as a cyst that can survive 2-5 weeks in faeces
  • non pathogenic E.dispar form eats bacteria
  • virulent form invades mucus lining and causes an abscess to form
  • amoebe may reach bloodstream, liver, lungs, brain but is treatable
37
Q

describe apicomplexans

A

spore forming, sexual and asexual, spread by sporozoites, parasitic (plasmodium)

38
Q

describe lifecycle of apicomplexan plasmodium

A

species include: P.vivax, P.ovale, P.falciparum, P.malgrige

  1. sporozoites divided at liver cells by fission forming merozoites
  2. merozoites enter infect red blood cells (asexual division)
  3. break out of RBCs, some develop into gametocytes
  4. mosquito bites human picking up gametocytes in blood
  5. gametes develop from gametocytes
  6. fertilisation in mosquito gut forms diploid zygote
  7. oocyst develops
  8. sporozoites develop in oocyst, migrate to salivary glands
  9. mosquito bites human, transferring sporozoites
39
Q

how can we attempt to control malaria?

A

drug treatment, GM males to attempt to sterilize them, gene editing for females so they don’t produce eggs

40
Q

what is apicomplexan toxoplasma gondii?

A

cat is the definitive host where the parasite reproduces and the rodent is the intermediate host which transmits the parasite. parasite influences host making them less afraid of cats when infected so more likely to go near the cats to pass it on

41
Q

a) describe flagellates

b) describe its free living form

A

a) asexual (binary fission), move by flagella, free living (trichonympha) and parasitic (trypanosoma)
b) trichonympha is in the gut of roaches and termites who eat cellulose which cant be digested. trichonympha breaks down cellulose into glucose producing enzyme B-glycosidase

42
Q

explain flagellate Trypanosoma brucei

A
  • causes sleeping sickness
  • has variant surface glycoproteins so is hard for immunity to be developed
  • transmitted by tsetse fly
  • sub species Gambiense: fly human fly, if untreated death 2-3 years
  • sub species Rhodesiense: fly game fly, death 6-8 weeks, zoonosis can occur
  • thought tsetse fly attracted to plain surfaces emitting even light
  • can trap tsetse flies using the smell of cow urine
43
Q

describe ciliates

A

asexual (binary fission- macronucleus), sexual (conjugation- micronucleus), move with cilia, free living (paramecium)

44
Q

describe ciliate paramecium

A
  • usually in ponds or freshwater
  • feed on micro-organisms
  • cilia waft food into oral groove and are used in locomotion
  • contractile vacuole controls water and expels excess liquid
45
Q

what are the 3 types of ova?

A
  • isolecithal (little yolk, evenly distributed)
  • telolecithal (yolk concentrated towards vegetal pole)
  • centrolecithal (yolk concentrated at centre)
46
Q

describe the stages during the acrosomal reaction in sea urchins

A
  • egg has protective jelly coat with chemoattractant properties causing sperm to migrate towards signals
  • sperm contacts the jelly coat and acrosomal vesicle with hydrolytic enzymes digests the jelly coat
  • acrosomal process forms and extends due to polymerisation of protein actin
  • process is coated with bindin which locks onto bindin receptors on vitelline layer
  • contact is made to egg pm stimulating sodium ion flow into egg, changing egg pm to positive
  • sperm cant cant on and are repelled (fast block to polyspermy)
  • sperm nucleus drawn into egg cytoplasm and fertilisation membrane forms and sperm and eggs merge
47
Q

what is the cortical reaction and slow block to polyspermy?

A
  • ca released from cytoplasm causes cortical granules to be released and fuse with plasma membrane
  • enzymes and solutes digest adhesion between pm and vitelline layer
  • vitelline layer polymerised by some enzymes becoming hardened
48
Q

what does the potential of the egg pm changing lead to?

A
  • metabolic changes in the egg
  • increase in protein synthesis and O2 consumption (prep for development)
  • ph change
49
Q

in sea urchin after how long

a) sperm and egg merge
b) replication and first division

A

a) 20 min

b) 90 min

50
Q

what are the 3 early stages of development?

A

cleavage, gastrulation, organogenesis

51
Q

what is cleavage and the 2 types?

A
  • rapid division of a single cell into a ball of cells known as blastomeres
  • can be complete or incomplete
  • radial cleavage is where the mitotic spindles are parallel/perpendicular to vertical axis for second division, cells form on top of others, cleavage is indeterminate (fate not fixed early on), organisms have top/bottom oral/aboral
  • spiral cleavage is where the mitotic spindles diagonal to vertical axis of embryo, can cause twisting of embryo, mitotic spindles tilt, cleavage determinate, front/back anterior/posterior and top/bottom dorsal/ventral
  • continued cell division forms a morula which forms a blastula
52
Q

what are the 4 blastula types?

A
  1. coeloblastula (hollow, 1 cell thick wall)
  2. stereoblastula (ball of blastomeres)
  3. discoblastula (blastomeres at animal pole)
  4. periblastula (1 cell thick blastomere layer around yolky mass)
53
Q

what is gastrulation?

A

blastula forms a gastrula with 3 tissue layers formed

  • connectivity is lost at the bottom, blastopore forms which goes on to become mouth or anus
  • endoderm and ectoderm form with mesoderm in the middle
54
Q

what is the archenteron?

A

embryonic gut which the filopodia help to push up during gastrulation

55
Q

whats the difference between endoderm, ectoderm, mesoderm?

A

ecto: outer layer, epidermis, CNS
endo: inner layer, gut, digestive tract, circulatory, respiratory
meso: middle layer, body cavity coelom, bone, muscle, blood

56
Q

whats gastrulation in mammals like?

A

blastula forms trophoblast (placenta) or inner cell mass which forms epiblast (embryo) or hypoblast (extraembryonic membranes)

57
Q

describe the 3 main body cavities

A

acoelomate: flatworms, lacks body cavity between gut and outer body
pseudocoelomate: roundworms, body cavity only partially lined by mesoderm
coelomate: earthworms, body cavity lined completely with mesoderm

58
Q

what are the 2 cell types that can be formed after the 8 cell stage and describe them

A

protostomes

  • spiral and determinate cleavage
  • mesoderm formed by splitting of mesoderm (schizocoelous)
  • mouth develops from blastopore

deuterostomes

  • radial and indeterminate cleavage
  • mesoderm formed from outpocketing of it (enterocoelous)
  • anus develops from blastopore
59
Q

how did porifera originate, what is the evidence and their likely ancestor?

A

from unicellular colonial flagellates around 700mya as flagellated cells are found in metazoans and many form colonies as well as molecular evidence links. choanoflagellates are the likely ancestor

60
Q

give 11 features of phylum porifera

A
  1. parazoa branch
  2. simple structure
  3. successful and widespread
  4. ancient group
  5. rigid, sessile, perforated
  6. lack muscle, NS and organs
  7. usually hermaphrodite
  8. asymmetrical
  9. cellular level organisation
  10. mainly marine
  11. can form relationships with others to move such as on shells of hermit crabs
61
Q

how do porifera forms vary depending on where found?

A

flat and low growing where lots of wave action but are larger where less current movement in deeper water so are large to get as much food as possible

62
Q

briefly describe features of the structure of a sponge

  • ostium
  • osculum
  • amoebocyte
  • choanocyte
  • spongocoel
  • spicule
A
  • water enters via incurrent pores (ostium)
  • cavity opens via osculum and water is expelled here
  • amoebocyte is where digestion occurs and food is taken from choanocyte and moved to other cells
  • choanocytes waft flagella to create a current and enable water flow into sponge, they line the inside of the sponge
  • spongocoel can help keep pores open
  • spicule can be calcareous, siliceous or made of spongin fibres
63
Q

how fast does water pass through a sponge?

A

at up to 20,000 times its volume in 24 hours

64
Q

what happens as the sponge gets larger?

A

the bigger the sponge the larger the choanocytes so a bigger current is generated

65
Q

give an example of a sponge

A

venus flower basket sponge- made of silicate and 75% tissues are syncitical (no cell boundaries between cells) and electrical impulses can travel through them

66
Q

how do sponges feed?

A

most are filter feeders taking in organic material from water or bacteria trapped in choanocytes which the amoebocytes engulf. but some are carnivorous with modified spicules to catch prey (harp sponge)

67
Q

why are filter feeder sponges important for coral reefs?

A

they generate nutrients. the ocean is poor in N and P. the C in the water is taken up by sponges and as bits of them die they are eaten by others so the other organisms then get the C

68
Q

can sponges regenerate?

A

in 1907 Wilson discovered that sponges can regenerate

  • put sponges through a sieve to see if reform and they did
  • also he mixed 2 different sponges before sieving and found they reformed as separate sponges and this was evidence for immunorecognition
69
Q

how do sponges reproduce asexually?

A

by budding or gemmules (internal buds that remain viable in harsh conditions and can form a new organism when conditions favourable)

70
Q

how do sponges reproduce sexually?

A
  • usually hermaphrodite
  • sperm expelled by osculum and engulfed by choanocyte
  • moved around sponge until egg is reached
  • larvae retained until blastula stage
71
Q

how are sponges biochemical agents?

A
  • some produce biotoxins
  • bright colours indicate toxicity
  • some chemicals have antibacterial activity
72
Q

what 2 branches does eumetazoa divide into?

A

radiata and bilateria

73
Q

give 8 features of cnidarians

A
  • 2 body layers: epidermis/outer and gastrodermis/ inner
  • mesoglea between the 2
  • limited organ development
  • simple form: blind sac with gastrovascular cavity
  • mouth=anus
  • simple nerve network and no brain
  • bundles of microtubules act as muscle
  • 2 forms exist: poly and medusa
74
Q

what do these cell types do in cnidaria?

  • cnidocil
  • epitheliomuscular cell
  • interstitial cell
  • neuron
  • enzymatic gland cell
A
  • cnidocil: contains nematocysts, cover the tentacles
  • epitheliomuscular cell: muscle system
  • interstitial cell: can transform into other cells
  • neuron: forms nervous system
  • enzymatic gland cell: discharges enzymes into gut
75
Q

what occurs at the gastrodermis?

A

digestion occurs intracellularly after reaching the gastrovascular cavity

76
Q

what is a nematocyst?

A
  • designed to capture and stun prey
  • contain coiled, hollow, barbed thread to ward off enemies or capture prey
  • stimulated mechanically and chemically
  • ca builds up, osmotic pressure changes
  • thread uncoils when stimulated and penetrates and paralyses prey
  • often inject venom/toxins
77
Q

whats key about the glaucus sea slug?

A

glaucus sea slug is a mollusc but it has nematocysts like cnidarians due to eating cnidarians and retaining the nematocysts as a form of defence

78
Q

what are the 4 main cnidarian classes?

A
  • hydrozoa
  • scyphozoa
  • cubozoa
  • anthozoa
79
Q

give 3 features of hydrozoans

A
  • usually colonial
  • sometimes show secondary polymorphism where polyp stage/parts can take on different functions
  • float
80
Q

whats the difference between the gastrozooid and gonozooid?

A

in cnidarians gastrozooid is for feeding and gonozooid is for reproduction

81
Q

what is hydra?

A

freshwater hydrozoan with no medusa stage and no planula larval stage

82
Q

what are siphonophores?

A

the most sophisticated hydrozoan- clusters of feeding polyp colony with individuals of different functions hanging below the swimming bell connected by a logn stem

83
Q

give 8 features of scyphozoans

A
  1. medusa phase dominant
  2. increase in sea temp can cause them to move to areas they aren’t usually found with little nutrients and can disrupt food chains
  3. radial symmetry
  4. outer epidermis and inner gastrodermis separated by jelly like mesoglea
  5. muscle cells allow umbrella to pulse for movement, as well as relying on currents
  6. simple eye- pigment cup
  7. statocyst senses gravity
  8. rhopalium are nerve cells that can control rhythm of pulsations
84
Q

give 6 features of cubozoa

A
  1. toxic (nematocysts can be venomous)
  2. active swimmers (2m per second)
  3. pursue prey such as fish
  4. four evenly spaced tentacles
  5. sophisticated eyes
  6. can use navigation signals from shoreline and land to orientate and navigate themselves
85
Q

give 8 features of anthozoans (sea coral/anemone)

A
  1. polypoid
  2. colonial or solitary
  3. medusa phase absent
  4. water entering allows it to become rigid
  5. water can circulate, entering via septal perforation- good for diffusion and respiration
  6. septum increases SA
  7. hollow tentacles
  8. thick mesoglea
86
Q

how do anthozoans reproduce asexually?

A
  • pedal laceration: slide along base dropping off bits of themselves
  • longitudinal fission: strip down the middle forming 2 individuals
87
Q

how do anthozoa reproduce sexually?

A
  • hermaphrodite
  • fertilisation in gastrovascular cavity or the sea
  • planula larva produced
88
Q

describe the symbiotic relationship between clownfish and anemone

A
  • clownfish lives in anemone tentacles but doesn’t trigger nematocysts
  • fish benefits from feeding on what anemone has and gets protection
  • anemone benefits as fish helps increase O2 and nibble the tentacles to keep it clean
89
Q

describe the symbiotic relationship between anemones and stony coral

A
  • carbon is fixed by zooxanthellae (photosynthetic algae in gastrodermis)
  • polyp generates waste, picked up by algae
  • food is caught by coral
  • zooxanthellae obtain inorganic ions from sea and aid in deposition of calcium carbonate reef skelton
  • if no zooxanthellae coral bleaching occurs
90
Q

within cnidarians what is the brief phylogeny?

A

anthozoa-> hydrozoa -> scyphozoa (medusa stage more derived as is only in the last 2 groups)

91
Q

give 9 features of platyhelminthes

A
  1. bilaterally symmetrical
  2. protostomes
  3. no coelom (acoelomate)
  4. triploblastic (3 body layers)
  5. cephalisation
  6. organs
  7. dorso ventrally flattened
  8. simple internal structure
  9. no blood system, rely on diffusion
  10. gut has one opening
  11. simple excretory system involves the protonephridia (flagella waft fluid into it, absorbing useful substances)
92
Q

what is xenacoelomorpha?

A

basal bilateral simple structured organism that was thought to be platyhelminthes but aren’t

93
Q

what are turbellarians?

A

free living platyhelminthes, non parasitic

  • covered in epidermis
  • nervous tissue concentrated at anterior end
  • the auricle detects chemicals
  • simple eye detects light
  • male and female reproductive tissue
94
Q

how was the regeneration of platyhelminthes studied?

A
  • investigated if will reform when chopped up, they did
  • further down cut, longer head takes to form
  • small section cut then 2 heads can form
  • cells are pluripotent, being able to form any other cell in the body so regeneration can occur
  • studied further by Thompson and McConnell in 1950s/60s
  • trained flatworms ro be shocked when bright light displayed
  • cut up worms and reformed and both halves responded as though shocked
  • fed trained worms to untrained and they responded with shock response
    BUT observer bias proven
95
Q

what is penis fencing in platyhelminthes?

A

being female is costly so fight for which of the pair becomes the female. fight with penis to try to inseminate the other first

96
Q

give 6 parasitic adaptations of platyhelminthes

A
  • loss of unwanted organs
  • penetration devices (enzymes produced so can burrow into host)
  • attachment devices (suckers/hooks)
  • protective devices (covering/ produce chemicals to stop digestive enzymes working)
  • transmission via vector
  • production of eggs in large numbers
97
Q

how many more eggs do parasitic flatworms produce than free living flatworms?

A

10,000-100,000 times more

98
Q

give 4 features of flukes- trematodes (platyhelminthes)

A
  • found inside animals
  • have tegument (tough covering) that is non ciliated syncytium (no cell boundaries)
  • have oral and ventral suckers
  • mostly full of reproductive tissue
99
Q

describe the generalised life cycle of a fluke

A
  1. egg hatched in water
  2. intermediate host usually a snail- miracidium form here
  3. germinal cells formed in sporocyst
  4. redia formed
  5. develops into cercaria with ventral and oral sucker
  6. larvae released from snail to swim to second host- metacercaria formed
100
Q

what do blood flukes/ schistosomatidae do?

A
  • cause schistosomiasis

- worms burrow into skin of human host and live in veins of intestine which can lead to blood in the urine

101
Q

what does D.spathaceum fluke do?

A

causes cataracts to from on eyes of intermediate host fish so are more likely to be predated by final host sea bird

102
Q

what does the lancet fluke do?

A

balls of mucus containing larvae are eaten by intermediate host ants causing them to clamp onto grass strands when colder weather making themselves more vulnerable to being eaten by final host cow/sheep

103
Q

how can trematodes be cooperative?

A

different forms of flukes can group cooperatively to carry out a function

  • soldier groups are aggressive, smaller and non reproductive
  • reproductive groups
104
Q

give 7 features of cestoda (platyhelminthes)

A
  • live in gut
  • tegument
  • no gut themselves
  • scolex is the head region
  • strobila are the repeated segments
  • intermediate hosts
  • full of reproductive tissue
105
Q

what does the beef tapeworm (T.saginatus) do?

A
  • enters muscle tissue of cow
  • bladder worms form in muscle tissue
  • human infected by ingesting meat if not cooked properly
106
Q

when does self fertilisation occur in tapeworms?

A

when only 1 tapeworm in host

mature as males first then females- sperm can be transferred to functional female area

107
Q

what are advantages of having a coelom?

A
  • transport: movement of nutrients in fluid and gas exchange can occur)
  • gut moves independently of body wall
  • site for gametic maturation in fluid
  • hydrostatic skeleton (rigid but allows for movement)
108
Q

annelids can move by peristalsis describe this

A
  • wave of muscle contraction
  • penetration anchor prevents back slipping when burrowing into sediment, the long thin circular muscles contract
  • terminal anchor allows for trailing part of body to be puleld forward, short fat longitudinal muscles contract
109
Q

a) what is the benefit of metameric segmentation in annelids?
b) what is the prostomium and pygidium?

A

a) makes locomotion more efficient and precise

b) head and tail

110
Q

in annelids which structures run the length of the animal and which are repeated in each segment?

A
  • gut and nervous system run length

- nephridium openings repeated

111
Q

in annelids what does the septum and nephridium do and what kind of circulatory system do they have?

A

septum divides segments, nephridium acts as a kidney and closed circulatory system

112
Q

in what 3 ways can segmentation be modified by?

A
  1. restriction of structures to particular segments (reproductive tissue only in certain segments)
  2. some segments develop special structures (head)
  3. segments may fuse together
113
Q

describe ultrafiltration in annelids

A
  1. ultrafiltration site is on a blood vessel forming primary urine
  2. modification occurs to produce final urine which is released to the exterior
  3. modification involves reabsorption of useful metabolites and secretion of toxins from blood or coelomic fluid
  4. pressure of ultrafiltration due to muscular contractions of vessel wall
114
Q

what are the 3 main groups of annelids

A
  • polychaeta
  • oligochaeta (clitellata- earthworms)
  • hirudinea (clitellata- leeches)
115
Q

give 3 features of polychaetes (annelids)

A
  • parapodia and lots of bristle like setae
  • each segment has a pair of parapodia (gas exchange occurs here and it increases SA)
  • prostomium (head) well developed
116
Q

describe the 2 groups of polychaetes: errant and sedentary

A
errant
- move a lot
- well developed parapodia
- active hunters
- ragworm
sedentary
- tube dwelling
- suspension feeding (water current passes between tentacles, tracts remove matter directing it to longitudinal food groove, large particles rejected and smaller ingested
- sabella
117
Q

describe arenicola

A
  • polychaete
  • sedentary
  • live in burrows/tubes
  • reduced parapodia as are burrowers
  • draws in sand to feed from one end of the burrow and deposit waste at the other end
118
Q

what is polychaete reproduction like?

A

dioecious, external fertilisation, spawning can be synchronous

119
Q

some polychaetes undergo epitoky, what occurs?

A

it is a body transformation such as metamorphosis into a reproductive form so can swim for longer, or will only spawn at a particular time of year

120
Q

give 4 general features of clitellata

A
  • no parapodia
  • produce clitellum and cocoons (clitellum helps produce cocoon which is where eggs develop and are fertilised)
  • hermaphrodite
  • gonads are restricted to a few segments
121
Q

give 7 features of oligochaetes/earthworms

A
  1. few setae
  2. peristaltic locomotion
  3. well developed septa used in peristalsis
  4. some live on surface and some burrow
  5. some feed on soil or bring food from surface into soil
  6. gas exchange occurs on outer surface
  7. reproduce by mutual sperm transfer
122
Q

describe reproduction in lumbricus worm

A

mutual sperm transfer

  • worms pair up head to tail bound by substance produced by clitellum
  • sperm released by male gonopore of 1 male travelling down sperm groove to opening of the other
  • clitellum produces lots of mucus and the cocoon
  • sperm is passed to female gonopore and eggs and new worms develo in cocoon
123
Q

give 10 features of hirudineans (annelid)

A
  • no setae
  • restricted to 34 segments
  • mutual sperm transfer
  • no clear division of septa
  • predaceous
  • jaw like structures
  • eat small inverts
  • blood suckers (produce anticoagulant hirudin)
  • use symbiotic bacteria to break down blood and can take up to 10X body weight in blood
  • crawl with suckers as have no septa and the well developed longitudinal muscles aid the movement
124
Q

give features of a generalised mollusc

A
  1. visceral mass surrounded by mantle covering which secrete shell if they have one
  2. mantle cavity contains gills and cilia cause movement across the gill
  3. nerve ring with branches goes to visceral mass and foot
  4. foot can be used for movement (muscles act antagonistically acting on cells filled with fluid to develop waves of contraction)
  5. radula is a feeding device of a conveyor belt of teeth that grind away at algae
  6. open circulatory system
  7. body plan very plastic
  8. seven different types of mollusc
125
Q

describe the circulatory system of molluscs

A

open- in the haemocoel

  • oxygenated haemolymph pumped from ventricle to haemocoel bathing organs
  • drains into channels, chambers and branchial vessels
  • O2 picked up by conidia and transported to atria and ventricles an back to haemocoel
126
Q

what 4 changes make gastropoda different from the standard mollusc?

A
  • development of head
  • dorso ventral elongation of body (often coiling of visceral mass)
  • shell forming a protective shield
  • torsion
127
Q

what is torsion and the advantage of it?

A
  • protection of veliger larva stage
  • protection of adult
  • utilisation of oncoming water by gills
128
Q

what is a disadvantage of torsion and how has this been combatted?

A

anus over head

- modifications of mantle cavity to solve sanitation problem and water flow

129
Q

what is de-torsion?

A

undergone torsion but then gone back to normal as still have some twisting to do which occurs due to differential growth and muscular contraction- such as sea slugs

130
Q

what are the 2 types of spiralling in gastropods?

A

planospiral- symmetrical
conispiral- asymmetrical

initially thought to be planospiral but now conispiral as shifted over to the right side

131
Q

what are the most specialised gastropods?

A

pulmonates

  • no gill and mantle becomes vascularised into a lung wall
  • evolved when O2 short so needed another way to access it
  • can exploit terrestrial environment
  • hermaphrodite
132
Q

what is partula?

A
  • gastropod that is species rich on the islands of tahiti
  • issue with predator african land snail
  • introduced predator rosy wolfsnail to eradicate african land snail but actually preferred partula snail
133
Q

what are lamellibranchs?

A

filter feeders

134
Q

give 8 features of bivalves

A
  • most are lamellibranchs
  • most dioecious
  • laterally compressed
  • shell made up of 2 hinged parts
  • reduced head and nervous system
  • no radula
  • can use foot for feeding with cilia gathering food
  • draw in water into mantle cavity over gills
135
Q

give 3 examples of bivalves

A

a) mussels- attach themselves to rocks as are in intertidal zone due to byssus threads (strong silky fibres made from proteins to attach to rocks
b) giant clams- have symbiotic relationships with algae for additional C source
c) scallops- eyes on mantle cavity and can use shells for movement

136
Q

give 14 features of cephalopods

A
  • marine carnivores
  • orientation of body changed
  • shell reduced/lost
  • closed circulatory system
  • foot modified into tentacles
  • mantle cavity relies in muscle contraction not cilia
  • can move by jet propulsion
  • some have ink sac which releases ink with irritant forming cloud so predator cant see
  • chromatophores in skin mean can change colour for disguise or mating
  • well developed nervous system (good memory and learning skills)
  • well developed eyes
  • not good at picking up sound
  • radula present so can produce neurotoxins
  • water pumped by muscular action
137
Q

describe the circulatory system of cephalopods

A

closed

  • have main heart and accessory hearts
  • blood pumped into gills
  • high metabolic rate and are active predators
138
Q

what are nautiloids?

A

molluscs

  • first appeared in cambrian
  • animals live in end of chambered shell which is filled with air rather than water to aid with buoyancy
  • can change amount of air and fluid in chambers
  • simple eye
139
Q

what does coleoidea include?

A

cuttlefish
- internal shell/cuttlebone used as buoyancy device
squid
- shell reduced to proteinaceous pen for support
octopus
- shell vestigial/absent

140
Q

give 9 features of arthropods

A
  • largest animal group
  • metamerically segmented
  • appendages on segments
  • grouped with nematodes as both undergo molts
  • marine, freshwater and air
  • no peristalsis but muscles are attached to cuticle
  • open circulation using haemocoel
  • special structures for gas exchange as body impermeable to gas
  • growth by ecdysis
141
Q

in arthropods how are they evolutionarily modified?

A
  1. groups of segments specialised (tagmatization)

2. specialisation of appendages

142
Q

what is a cephalothorax?

A

where the head and thorax join

143
Q

do arthropods have hox genes?

A

yes- first discovered in drosophila

  • controls anterior posterior axis
  • tells cells which segment they are in
  • highly conserved
144
Q

describe the cuticle in arthropods

A
  • resilient to desiccation
  • allowed movement onto land
  • EPICUTICLE: made of proteins and wax- lightweight and waterproof
  • EXOCUTICLE: tough pigmented tanned layer where cross links form
  • MESOCUTICLE: protein and chitin bind to form glycoprotein
  • EPIDERMIS: secretes the cuticle
145
Q

in aquatic arthropods what can harden the cuticle?

A

ca salts

146
Q

describe ecdysis in arthropods

A

shed old cuticle and grow a new one

  • take up water/ air to make self bigger as cuticle hardens so new cuticle is bigger than body so can grow into it
  • after each molt new features form, increasing weight of organism
147
Q

what is the largest terrestrial and the largest aquatic arthropod?

A

terrestrial: coconut crab (50cm)
aquatic: giant spider crab (4m)

148
Q

give 6 features of trilobites

A
  • have 3 body regions (cephalon, thorax, pygidium)
  • went extinct 250-270mya
  • compound eyes made up of ommatidia- lens leading to pigment cells
  • scavengers and filter feeders
  • 2 branched limbs
  • most trilobites outlasted by sea scorpions
149
Q

when did sea scorpions go extinct and what are the 2 main regions?

A

extinct 250mya

prosoma and opisthosoma

150
Q

describe the main 2 tagmata of chelicerates

A
  1. prosoma (cephalothorax)
    - 6 pairs appendages
    - chelicerae (pair of appendages at front of mouth, pincer like claws)
  2. opisthosoma (abdomen)
    - no distinct head and no antennae
151
Q

describe the marine chelicerate of a horseshoe crab

A
  • simple eyes used to detect opposite sex
  • gnathobase grinds up food
  • book gills used for respiration and are filled with blood and sea water and gas exchange occurs
  • chela of third walking leg gathers food
  • larvae develop in sediment
  • haemocyanin in blood
  • amoebocytes function like white blood cells
152
Q

what are terrestrial chelicerates known as?

A

arachnids

153
Q

give 6 features of scorpions

A
  • mostly carnivorous (often use neurotoxins on prey)
  • earliest group of chelicerates
  • grab prey with chelicera
  • use pedipalps in mating (male grabs female, drops spermatophore and leads her over it)
  • females show parental care can live young can stay on her back for weeks
  • telson and aculeus are stinging apparatus to inject venom
154
Q

give features of spiders

A
  • use pedipalps to mate
  • chelicera form fangs which release neurotoxins
  • small waist allows them to move their abdomen
  • spin silk (made of protein fibroin) produced by silk glands and released from spinnerets to form webs
  • can change consistency of silk
  • can use silk for ballooning where it gets caught in the wind so can move
  • can wrap food up and cocoon offspring
155
Q

in arachnids what do the malpighian tubules do and where does gas exchange occur?

A

malpighian tubes are used in excretion to absorb useful substances and expel waste
gas exchange occurs at the book lungs and trachea deliver O2 to tissues

156
Q

why is B.kiplingi spider different ?

A

it eats plant material- the beltian bodies of acacia bushes

157
Q

what is the stabilimentum?

A

a structure on the web that could attract mates or prey or be to prevent birds flying into it

158
Q

can spiders act cooperatively?

A

T.nigroannulatum is a cooperative spider species where they work together to capture larger prey using their silk

159
Q

describe ticks and mites within chelicerates

A

ticks
- ectoparasites
- some can transmit disease such as lymes disease which affects the nervous system and can cause paralysis
mites
- free living and parasitic
- dust mites and their faeces have strong allergens affecting people
- varroa feeds on haemolymph of honey bee

160
Q

give 4 features of pycnogonida

A

sea spiders

  • abdomen very small
  • 4 pairs legs
  • reproductive structures carried outside body- males will carry the fertilised eggs
  • ovigers are used to clean the legs
161
Q

give 10 features of crustaceans

A
  • predominantly marine but some occur in other in other environments
  • malacostraca main group
  • tagmatization and adaptive radiation of appendages
  • compound eye
  • pleopods can be used for swimming
  • 2 pairs antennae
  • 1-3 thoracic appendages may be incorporated into head (maxillipeds)
  • appendages biramous
  • filamentous branch can be enclosed to become a gill
  • legs have protopod and endopod as main 2 sections
162
Q

describe 5 features of the brine shrimp crustacean

A
  • basic paddle like appendages moving in metachronal waves
  • legs can be used to capture food and respire
  • in salt lakes
  • modified pleopod forms chelae
  • abdominal region is used for swimming
163
Q

describe crustacean daphnia

A
  • animal enclosed in a carapace which can open to allow water in
  • legs for food gathering and respiration
  • 2 pairs antennae, second pair well developed and used to swim
  • single compound eye
  • undergo parthenogenesis but in harsh conditions can reproduce sexually
164
Q

what is parthenogenesis?

A

reproduction from ovum without fertilisation

165
Q

describe crustacean barnacles

A
  • heads can be cemented to shell
  • simple body, mainly thorax
  • no abdomen
  • hermaphrodite
  • largest penis to body ratio in animal kingdom
  • goose barnacle
  • parasitic barnacle sacculina which latches onto crab growing into it and can feminise males by attacking their adrenal glands
166
Q

what is the larvae of crustaceans?

A

nauplius larva

167
Q

within myriapods there are centipedes and millipedes, describe both

A

centipedes

  • head and trunk
  • dorso ventrally flattened with legs out of sides
  • well developed poison claw/maxilliped
  • predaceous

millipedes

  • head and trunk region
  • spherical body with legs on it
  • move quickly
  • each segment has 2 pairs of legs
  • feed on plant material so no poison claw
  • emit hydrogen cyanide gas and other chemicals from repugnatorial glands
  • movement of air by muscles and diffusion
  • can lose water through spiracles
  • substances drawn into malpighian tubules from haemolymph
168
Q

what are the 3 tagmata in insects and what is found on the central one?

A

head, thorax, abdomen

thorax: 3 pairs legs and 2 pairs of wings

169
Q

what is the current hypothesis for the relationship among the 4 living subphyla of arthropoda?

A

chelicerata grouped with myriapoda and crustacea grouped with hexapoda

170
Q

give features of nematodes

A
  • pseudocoelomate
  • cuticle of collagen and cross links between the proteins make it tough and flexible
  • 4 moults
  • lots of pressure in the body
  • epidermal layer secretes the cuticle
  • largest over 8m in sperm whale placenta
  • mostly dioecious
  • internal fertilisation
  • strong muscles at entrance and exit
  • nerve chords run down from body from simple brain
  • females larger and sex is environmentally determined
171
Q

describe c.elegans (nematode)

A
  • free living
  • roughly 1mm
  • hermaphrodite
  • cells fate fixed early in development
  • set number of cells on body
  • first invertebrate genome sequenced
172
Q

describe the genes for enhanced longevity in nematodes

A

pha-4 is linked to enhanced longevity on restricted diet

  • if gene blocked no enhanced longevity
  • if overexpressed then longevity even longer
173
Q

describe parasitic nematodes and give 1 example

A
  • parasitism evolved several times in nematodes
  • radiation accompanied evolution of flowering plants, insects, amniotic vertebrates
  • parasitic as juveniles, adults or both
  • one or more intermediate lost
  • root knot nematode infects plants so crop yield and economy decreases and the nematode drains nutrients and photosynthetic products of plants
174
Q

describe the parasitic behaviours of:

a) s.morrisoni
b) m.neotropicum

A

a) infects amphipod meaning they swim to surface of water in daylight, birds more likely to feed on them
b) ant infected with nematode causes abdomen to swell and become red- attractive for birds to feed

175
Q

describe life cycle of a pinworm

A

indirect/ only in human cycle

  1. eggs enter host by ingestion
  2. eggs hatch in intestine
  3. larvae mature
  4. pinworm in human gut
  5. impregnated female migrates to hosts anal region at night
  6. zygotes released on host, bedclothes into airborne dust
176
Q

describe life cycle of hookworm

A

penetrates human skin and scrapes intestine

  1. eggs develops in soil
  2. rhabditiform larva hatches
  3. larvae molts
  4. penetrates human skin
  5. larvae enter circulatory system
  6. heart
  7. lungs
  8. trachea
  9. larvae enter esophagus and is swallowed
  10. larvae matures in intestine
  11. hookworm adult in human intestine
  12. fertilised eggs released in faeces
177
Q

what are asceroids?

A
  • larger nematodes
  • up to 50cm
  • indirect life cycle
  • lots of them so can block gut
178
Q

what is the guinea worm (parasitic nematode) lifecycle?

A
  1. live in subcutaneous tissue
  2. form an ulcer
  3. water touches it and larvae are released
  4. larvae released into copepod which is the intermediate host
  5. taken up in drinking water
  6. penetrate gut and lodge into subcutaneous tissue
179
Q

what’s an example of the filarial nematodes?

A

W.bancrofti

  • adults inhabit lymphatic glands
  • intermediate host
  • elephantiasis occurs (severe swelling of arms legs and genitals)
    1. mosquito bites
    2. adults in lymphatica
    3. adults microfilariae migrate into lymph and blood channels
    4. mosquito bites
    5. microfilariae penetrate mosquitos midgut and thoracic muscles
    6. migrate to head and mosquito’s proboscis
180
Q

whats the benefit of symbiosis in nematodes?

A

most nematodes form symbiotic relationships with bacteria meaning works can be treated with antibiotics as they kill bothe the worm and the bacteria

181
Q

give 7 features of echinoderms

A
  • pentamerous radial symmetry
  • body divided into 5 parts
  • not related to other radially symmetrical groups
  • 3 body layers
  • coelom
  • larvae bilaterally symmetrical
  • larvae show convergent evolution with other larvae even though not closely related to them
182
Q

whats the outer structure of echinoderms?

A

have an internal skeleton of ossicles

  • each ossicle caco3 has crystal structure separated by living tissue
  • ossicles can fuse to form a test (hinged hard outer casing)
  • some ossicles are minute/absent such as in sea cucumbers
183
Q

whats the purpose of tube feet/podia?

A
large= locomotion and feeding
small= respiration and suspension feeding
184
Q

describe the water vascular system of echinoderms

A

helps operate the podia

  • tiedemanns can ingest waste material
  • contains canals full of fluid which go down each of the legs
  • water flows between ampulla and podium (suction cup at the end)
  • sea urchins have suction cup at the podium for grip
  • others have chemical reaction occur for grip
185
Q

what is mutable connective tissue?

A
  • it can alter rigidity
  • under nervous control
  • due to changes in fluidity of collagen fibres in connective tissue
  • can eject organs to deter predators, these can be regenerated
186
Q

give 11 features of asteroidea

A
  • pedicellariae: jaw like and remove waste that may accumulate
  • ambulacral ridge is where the podia are found
  • mouth on underside oral side
  • papula is for gas exchange and excretion
  • sophisticated nerve net
  • control comes from radial nerves connected to nerve junction
  • connection at nerve junction important to podia to travel in same direction
  • local control can occur so parts can temporarily function as brain
  • if cut some arms will continue in theri direction but others wont know which direction to follow
  • short arms may swallow food whole
  • long arms can grab prey such as prying apart mussels and eject stomach to digest externally
187
Q

give 10 features of ophiuroidea

A

brittle stars

  • photosensitive
  • no ambulacral groove or ampullae
  • podia not used in locomotion but are feeding
  • bursal sites: respiration
  • feed: scavenging, deposit feeding, suspension feeding
  • ossicles form plates over body
  • mucus on podia allow it to catch prey
  • can change colour due to chromatophores in skin
  • radial nerves with ganglia
  • legs and spines can grip substrate
188
Q

give 3 features of echinoidea

A

sea urchins

  • spines and podia used for movement
  • ossicles fuse to form test
  • aristotle’s lantern made ossicles and forms a chewing device when feeding on rocks and larvae
189
Q

gives features of holothuroidea

A
  • ossicles very small
  • bilaterally symmetrical pattern but podia in a radial pattern
  • crown of 10 dendritic tentacles (modified podia)
  • deposit and suspension feeders
  • podia used crawling/gripping
  • attached or irritated tubules from anus and toxin (holothurin)
  • anus leads to canals for respiration at respiratory tree
190
Q

give 8 features of crinoidea

A

sea lilies and feather stars

  • mouth on top
  • most ancient group
  • free living
  • can move by waving arms
  • ossicles present at calyx
  • ciliated ambulacral groove
  • sea lilies use arms to feed and are in the deep sea
  • feather stars are free living and use their arms to move and swim, suspension feeders
191
Q

give 3 features of hemichordates

A
  • coelomates
  • half chordates
  • 2 main groups include enteropneusta and pterobranchs
192
Q

give 6 features of enteropneusta

A

acorn worms

  • burrow in mud forming tunnels
  • 9-200cm
  • proboscis collects food
  • gill slits are for respiration
  • larval stage echinoderm like
  • nerve net
193
Q

give 6 features of pterobranchs

A

sea angels

  • small (1-5mm)
  • sessile
  • colonial
  • lophophore (feeding device)
  • some have gill slits
  • can be traced back to graptolites in cambrian devonian period
194
Q

whats the resemblance of hemichordates to chordates?

A
  • no notochord
  • no tail
  • nervous tissue can be hollow
  • collect food externally
    but do have gill slits
195
Q

whats the resemblance of hemichordates to echinoderms?

A
  • similar larval stages
  • similar nervous systems
  • gill slits
  • more closely related to echinoderms than chordates
196
Q

what are the 4 features of a chordate?

A
  1. notochord
  2. dorsal hollow nerve cord
  3. pharyngeal/gill slits
  4. post anal tail
197
Q

give 7 features of invertebrates urochordates

A
  • metamorphosis in adults means they lose many chordate features and only the gill slits remain for filter feeding
  • adults usually sessile
  • free swimming larval tadpole stage has all chordate characteristics
  • solitary or colonial
  • water in the buccal siphon and out the atrial siphon
  • larvae swim and settle their head adhering to the surface
  • notochord and tail loose turgor and are reduced
198
Q

give 3 examples of urochrodates

A
  • sea squirt
  • salp (float in plankton)
  • larvacea (looks like larval stage but adult retains chordate features)
199
Q

give features of cephalochordates

A
  • filter feed with gill slits
  • adults retain all chordate features
  • similarities with other deuterostomes
  • dorsoventral axis inversion in chordates
  • genes and proteins that would be expressed ventrally for chordates are expressed dorsally for non chordates
200
Q

what are deep sea hydrothermal vents and what is the community here like?

A
  • form along mid ocean ridges (1500-3000m)
  • discovered late 1970s
  • extreme temp and pressure
  • ridges at boundaries of tectonic plates
  • cracks can form on sea floor and spreads as the plates move
  • cool water flows into cracks and is superheated by magma
  • hot vent fluid mixes with cold seawater
  • water forced out of plumes/black smoke full of nutrients and sulphides
  • vent fluid mineral rich to support ecosystems
  • primary producers chemoautotrophic microorganisms which break down sulphides oxidising them to form C compounds
  • bacteria can be consumed directly or form symbiotic relationships
  • vent communities have low numbers of species and diversity and high densities
201
Q

explain these deep sea vent organisms

a) scaly foot snail
b) yetti crab
c) giant tube worm
d) pompeii worm
e) swarming shrimp

A

a) iron sulphides on foot and shell
b) hair filamentous bacteria to protect from high temp
c)
- polychaete
- 3m long
- no gut
- tissues have symbiotic bacteria
- plume collects hydrogen sulphide and is transported in haemoglobin
d) - gallery dweller in vent
- tolerates high temp (80c)
- deposit feeder
- dorsal surface colonized by bacteria
- hair is filamentous bacteria for heat protection
- gill like structures increase SA
- lots of haemoglobin to collect low levels of o2
e) - heterotrophs
- bacteria grow in gill chamber (may farm them to feed on them)
- dorsal organ eyes

202
Q

how many species are vent fauna and what % are vent communities only and what can provide a key part of the community?

A

> 500 species
90% from vent only
whale carcasses provide food and community for feeding on flesh (zombie worm digs into the bones and feeds on fat and protein)

203
Q

what are the 2 major groups of vertebrates and within the second what are its 2 major lineages?

A
  • non amniotes (embryo enclosed and protected by mebranes and reproductive tract)
  • amniotes (additional set of membranes and include sauropsids/ birds and reptiles and synapsids/mammals
204
Q

how many orders are there in:

a) mammals
b) birds
c) reptiles
d) amphibians

A

a) 26
b) 23
c) 4
d) 3

205
Q

briefly explain how the terrestrial vertebrates came to evolve

A

550MYA: separate continents
300MYA: one single continent pangea through merging of others through continental drift- new niches form
150MYA: pangea broke apart
vicariance/geographical separation allow diversity to occur

206
Q

how has the number of taxa within vertebrates increased over time?

A

increased exponentially with it reaching its max 12-14 mya and has been declining since

207
Q

what is the smallest fish and the smallest frog?

A

fish: paedocypris, 7.9mm. discovered 2005 in peat swamps
frog: p.amauensis, 7mm, discovered 2012

208
Q

how do the reproductive behaviours of vertebrates vary?

A

oviparous (egg laying)
viviparous (live young)
ovoviviparous (live young from eggs that hatch within body)

209
Q

what type of speciation are darwin’s finches?

A

allopatric

210
Q

what is convergence and evidence for it in vertebrates?

A

same selection for similarity

  • such as body shape in ichthyosaur, porpoise, shark
  • forelimb homologies in turtle, dolphin, horse, fruit, bat, chicken, human
211
Q

are reptiles monophyletic group?

A

no

212
Q

traditionally what were classification systems based on and what are they based on now?

A

all are based on similarity

  • traditionally phenetic methods where equal weight is given to all characters
  • now phylogenetic classification where characters are weighted based on evolutionary origin
213
Q

whats the difference between homology and analogy?

A
homology= shared ancestry between structures/genes in different taxa
analogy= resemblance of function between organs with different evolutionary origins
214
Q

when studying vertebrate phylogeny based on DNA sequence data how many new species of fish, rodents, bats, primates are discovered each year?

A

> 300
174
94
55

215
Q

roughly what % of vertebrates are endangered?

A

20%

216
Q

what have most vertebrates lost and what do they use their gill slits for?

A

lost notochord and gill slits used for breathing

217
Q

what is the endostyle for in vertebrates?

A

produces mucus and can retain iodine to make thyroxine

218
Q

what 10 main features make vertebrate chordates differ from the invertebrate ones?

A
  • vertebrae
  • cranium
  • duplication of hox gene complex
  • development of neural crest
  • placodes
  • brain of vertebrates larger and with 3 parts
  • increased body size and increased activity
  • cant rely on ciliary action or diffusion
  • higher metabolic rate than invertebrate chordates
  • can sustain periods of anaerobic respiration
219
Q

describe the vertebrae

A
  • usually replaces notochord
  • made of cartilage or bone
  • grows around nerve cord
  • support and protection
  • hagfish and lampreys don’t have a fully formed notochord
220
Q

describe the cranium

A
  • bony cartilaginous and fibrous

- protects the brain

221
Q

what are hox gene duplications associated with?

A

the evolution of other features and development of complex traits
the first duplication was the origin of the vertebrates

222
Q

how did the neural crest develop and what is it responsible for?

A
  1. neural crest plat gives rise to nervous system
  2. neural tube forms as neural crest folds
  3. as neural tube closes neural crest cells determinate and migrate out of the ectoderm
  4. could be regarded as another germ layer- quadroblastic
    - responsible for new structures especially in the head
    - are precursors of neural crest in invertebrate chordates (tunicates and amphioxus have similar genes expressed to vertebrate neural crest formation)
223
Q

what are placodes?

A

embryonic structures giving rise to complex sense organs (hair follicles, feathers, teeth)

224
Q

give 10 primitive vertebrate features

A
  • head extended beyond notochord
  • cranium supporting brain
  • tripartite brain with multicellular organs
  • can detect water movement
  • improved distance sensation
  • pharynx with specialized muscle
  • vascularised gut
  • 3 chambered heart
  • closed circulatory system with extensive capillary network
  • body fluid more dilute than water
225
Q

what kind of tissue do vertebrates have and describe this

A

mineralised tissue

  • contains unique mineral hydroxyapatite
  • means more resistant to lactic acid build up after anaerobic respiration
  • can be collagen fibres, proteinaceous tissue matrix or hydroxyapatite
226
Q

what are the 5 types of mineralised tissues and explain each

A
  1. mineralised cartilage- forms main mineralised internal skeletal tissue of sharks
  2. bone- internal skeleton of bony fish and tetrapods, highly vascularised and 70% mineralised, 2 types include dermal in skin and endochondral in body
  3. enamel (96% mineralised) and dentine (90%)- associated with teeth or exoskeleton
  4. enameloid- teeth and dermal scales of cartilaginous fish, 96% mineralised
  5. cementum- fastens teeth into sockets, 45%
227
Q

what was the origin of mineralised tissues and why did they evolve?

A
  • no mineralised tissue at start of vertebrate evolution
  • basic units in early vertebrates knows as dermal odontodes (dermal armour in skin of ostracoderms and are similar to shark denticles)
  • defensive structure
  • protected electroreceptors
  • regulation of phosphorus calcium and mineral storage
228
Q

give 2 examples of some of the earliest vertebrates

A
  1. conodonts - 500MYA, unclear where in vertebrate evolution, have mineralized tooth like structures in pharynx
  2. myllokunmingia- 530MYA, chordate features and skull and skeletal elements are made of cartilage
229
Q

where did early vertebrates originate from and what is the evidence for this?

A

marine environment

  1. paleontological- earliest fossils in marine sediments
  2. comparative physiology- invert chordates and other deuterostomes marine and body fluids are isotonic/same conc as mairn water
230
Q

what is an example of an extinct agnatha?

A

ostracoderms (500MYA)

  • jawless
  • derived forms thought to have paired fins
  • more derived than modern day agnathans
  • plates in mouth indicate most likely fed on soft bodied animals
231
Q

what are present day agnatha known as and what 2 does it include?

A

cyclostomes

lampreys and hagfish

232
Q

what is cyclostome haemoglobin like?

A
  • alpha and beta globins
  • 500mya ancestral globin gene split giving rise to alpha and beta genes
  • jawless vertebrates the only vertebrates that don’t show this alpha/beta split
  • common ancestor of lampreys and hagfish predates split so diverged before this
233
Q

give 11 features of lampreys

A
  • most predaceous mainly attacking bony fish and marine mammals
  • sucker like feature to latch onto prey- oral hood with teeth to rasp at flesh
  • notochord supports body as vertebrae minute
  • tongue
  • single nostril on top of head
  • well developed eyes
  • pineal eye can detect light
  • respiratory tube combined with gut
  • velum prevents water flowing back into mouth
  • ventilates using gill slits by tidal ventilation drawing water in and out
  • larvae are filter feeders
234
Q

where do lamprey move to to breed and how?

A

adult life spent in sea but return to freshwater to breed (anadromous)
- females use stones to build nests and lay eggs and sperm shed over the eggs
find freshwater streams by pheromones released by larvae
- pheromones made up of: petromyzonal sulphate, petromyzonamine disulphate, petromyzosterol disulphate
- detected at low concentrations and produced in large quantities

235
Q

explain the lamprey colonisation of the great lakes USA in 1920s

A
  • larvae are landlocked in the great lake so rather than returning to the marine environment they remain in freshwater
  • parasitic phase occurs in lake
  • mature adults migrate to streams
  • larval stage in streams then migrate to lakes
236
Q

what are the 3 main types of british lamprey?

A

brook lamprey- don’t feed as adult (all over UK)
river lamprey- coastal water as adult
sea lamprey- larger and found in open ocean

237
Q

give 12 features of the hagfish

A
  • scavengers and predaceous
  • slime produced could clog gills of other fish
  • can acquire nutrients through skin and gills
  • notochord for support
  • only vertebrates with blood isosmotic to sea
  • slime produced by glands
  • sex ratio female biased
  • single nostril for the intake of water
  • external gill opening
  • tongue with teeth
  • no larval stage (develop in egg)
  • can tie themselves in knots to feed or get rid of excess slime
238
Q

how did the jaw evolve?

A
  • enabled vertebrates to feed on wider variety of prey

- evolved from anterior branchial arch/mandibular arch

239
Q

what arches support the gill slits and what does arch enlargement aid?

A

branchial

enlargement aids ventilation and arch is functioned in closing and opening entrance to pharynx

240
Q

what did Mallat propose?

A

1996- ventilation hypothesis

  • mandibular arch does not form functional gill arch in any living vertebrate or fossil form
  • first gill arch never used in respiration
  • lampreys and hagfish mandibular arch not used in respiration
  • gnathostome can suck in prey and grasp in with mandibular arch
241
Q

what do paired fins allow for and what is pitch and yaw?

A

to move around effectively and stabilize the body (also protection and mate attraction)
pitch= up and down movement controlled by pelvic and pectoral fins
yaw= side to side movement controlled by dorsal and ventral fins

242
Q

what are the genes responsible for the dorsal fin of lamprey also responsible for?

A

the midline and paired fins in bony fish and later on controlled limb development

243
Q

give 7 features of gnathostomes

A
  • jaws containing teeth which form from mandibular gill (teeth homologous to denticles)
  • robust gill musculature
  • hypobranchial musculature allows for suction during inhalation and suction feeding
  • well developed vertebrae (centrum and ribs surrounding nerve chord)
  • mouth and gills operate as double pump
  • nostrils leading into 2 olfactory bulbs
  • lateral line system to detect mechanical pressure
244
Q

what are placoderms?

A
ancient gnathostomes (430-360mya)
armoured prehistoric fish with head and thorax covered in armoured plates and the rest of the body is scales
245
Q

what does the clasper do?

A

used in reproduction as an intromittent organ for internal fertilisation to occur (placoderms)

246
Q

what are acanthodians?

A

spined extinct jawed fishes

  • some toothless others have tooth whorl
  • could be related to cartilaginous fish as share features with them
  • resemble sharks
247
Q

give 5 features of chondrichthyes

A
  • first appeared 400MYA
  • cartilaginous skeleton make it manoeuvrable, can lighten the body
  • lipid filled liver can provide buoyancy
  • high blood urea concentration, less dense so more buoyant
  • most have hyostylic jaw suspension
248
Q

what is hyostylic and amphistylic jaw suspension?

A

hyostylic= upper jaw detached from skull but attached by gill arch so can move jaw independently of cranium

amphistylic= ancestral form with some attachment to skull and support from gill arch

249
Q

what are the 2 main subgroups of chondrichthyes

A
  • holocephali (rat fish)

- elasmobranchs (sharks, skates, rays)

250
Q

give 7 features of holocephali

A
  • well developed pectoral fins
  • can have whip like tail
  • upper jaw fused to cranium (holostylic)
  • feed on crustaceans
  • spines can produce toxins
  • head clasper used in mating to grab females neck
  • head rich in mechano and electro receptors
251
Q

what are the 2 types of elasmobranchs

A

squalomorpha

  • no anal fin
  • live in cooler, deeper water
  • hammerhead shark (head shape could enable binocular vision)

batoidea- skates and rays

252
Q

give 8 features of batoidea, elasmobranchs

A
  • enlarged pectoral fins
  • benthic
  • some produce electric currents (rays can produce 200 volt shock)
  • rays have barb for defence
  • skates have dorsal fins on tails and lay eggs
  • rays give birth to live young
  • cephalic fins when swimming, such as manta ray, allow water in and filter feeding
  • skates can produce low current for communication
253
Q

what are elasmobranchs gut like?

A

short gut with spiral valve to increase SA

254
Q

what type of tail do elasmobranchs have?

A

heterocercal: asymmetrical with top longer than the bottom

255
Q

what are the scales of sharks ?

A

placoid scales

  • improves water flow over body
  • homologous to teeth
  • young sharks can use denticles to aid feeding
256
Q

what forms due to sharks lacking dermal bone?

A

teeth form within skin and a tooth whorl rests on the jaw

257
Q

what 3 types of receptors do chondrichthyes have?

A

mechanoreceptors- detect vibrations using neuromast organs

chemoreceptors- acute sense of smell, 1 part in 10 bn, will turn to the side stimulated first

electroreceptors- ampullary organs in the head of sharks and pectoral fins of skates and rays detect electrical impulses of prey

258
Q

what is. the vision and brain liek of chondrichthyes?

A
  • well developed vision for low light intensities
  • rod rich retina with cells with crystals of guanine forming a mirror like structure behind the retina
  • brain proportionally heavier than other fish
  • similar brain to body mass ratio of some tetrapods
259
Q

what is the sequence of systems for chondrichthyes?

A

olfaction particularly if prey wounded or mechanoreception
vision for prey detection- will bash into prey to smell blood if cant see
use electroreception to attack
kill prey by exsanguination (draining of blood)
- bite force 1800kg, megalodon 18,000kg

260
Q

how do sharks reproduce?

A
  • internal fertilisation
  • most species lay eggs and males fertilize them
  • males may wrap around female and insert his claspers into females cloaca
  • females skin may be thick to account for males latching on
  • can be oviparous
  • ovoviviparous
  • viviparous
261
Q

what are viviparous shark species like?

A
  • some females secrete substances in reproductive tract
  • some ovulate to feed young
  • sometimes young feed on each other
  • some have yolk sac placenta
  • once born/ eggs laid there is no parental care
262
Q

compare general shark life history parameters to atlantic cod

A
  • sharks take longer to reach maturity
  • larger size at maturity
  • slightly longer lifespan
  • fewer offspring in a ‘litter’
  • reproduce biennially rather than annually
  • reproduce later in life
263
Q

give 6 features of osteichthyes and the 2 main groups

A
  • > 30,00 species
  • > 95% all fish
  • bony fish
  • first fossil approx 400MYA
  • mineralised tissues as scales
  • radiated in devonian into the 2 groups
    actinopterygii (ray finned)
    sarcopterygii (lobe finned)
264
Q

describe 2 non-teleost osteichthyes

A

sturgeon

  • cartilaginous skeleton but though to have lost bone
  • swim bladder type structure
  • petrutable jaw
  • lost many scales, scoot instead
  • used in caviar industry

paddlefish

  • cartilaginous skeleton and lost bone
  • extension from cranium full of organs detecting electrical signals
  • fish feeder species found in china and filter feeder in US
  • paddle detects electrical impulses, similar to ampullary organ of sharks
265
Q

give 12 features of teleost osteichthyes

A
  • specialisation of feeding mechanisms
  • flexibility of bone of skull and jaw so can exploit a range of prey
  • jaws act as a suction device to increase the volume of the buccal cavity
  • feed by suction feeding (mouth opens, buccal cavity increases and expands to draw water in)
  • pharyngeal jaws
  • cichlids may account for diversity in diet and feeding
  • modified gill arches help process food in mouth
  • homocercal/symmetrical tail to provide powerful force and keep fish in 1 horizontal plane
  • swim bladder provide buoyancy
  • small scales
  • can use fins to attract females
  • lateral line system detecting water displacement
266
Q

what is different about the moray eel?

A

accessory second jaw that launches out to grasp and kill prey helping to move it down esophagus- raptorial pharyngeal jaw
(lives in crevices so cant use suction feeding as well)

267
Q

how are swim bladders formed and what did ancestral bony fishes have?

A

ancestral bony fishes had lungs similar to lungfish

  • swim bladder formed by outpocketing of gut during development
  • initially developed as lung but is a swim bladder in bony fish
  • maintains buoyancy of fish
  • can compress if pressure increases in deeper water
  • can gulp at surface to increase volume of swim bladder with O2
268
Q

typically how do bony fish respire ?

A

mouth has pump which opens and closes drawing water in
operculum covers gills
water in mouth, over gills and out operculum
continuous current created by mouth and operculum
- blood and water in opposite directions (countercurrent exchanger so maximises amount of O2 going into blood)
- warm blood from capillaries in muscle transfers heat to arterial blood

269
Q

what is an alternative way fish can ventilate?

A

ram ventilation

  • fish may swim with their mouths open rather than pumping mechanism
  • must be active for water to go over gills
270
Q

what is regional heterothermy in fish?

A

fast moving fish can keep muscles 10c higher than surrounding water- maintain different temp zones in different body regions

271
Q

what are anabantoid fish and the dwarf gourami?

A

obligate air breathers in order to survive

have lung like labyrinth organ where gas exchange occurs

272
Q

what does catadromous mean?

A

live in freshwater but migrate to spawn in marine environment

273
Q

give 6 features of eels (actinopterygii)

A
  • european/north african and american
  • reduced fins and no pelvic fins due to living in vegetation and mud
  • undergo migrations when they spawn to marine environment (catadromous)
  • schmidt discovered eels spawn in sargasso sea in 1923
  • suffering exploitation
  • swim by generating body waves that travel the length of the body
274
Q

what are 3 types of sarcopterygii?

A

lungfish
coelacanth (deep sea fish thought to be extinct but rediscovered in 1938)
tetrapodomorph fishes (gave rise to tetrapods)

275
Q

what are the 3 genera of lungfish?

A

neoceratodus- australia
protopterus- african
lepidosiren- s american

276
Q

give 4 features of lungfish?

A
  • can use fins to move around on the floor as they burrow in mud and when water dries out
  • developed lungs allow them to breathe air in water with low O2 levels
  • lung is a modified swim bladder to absorb O2 and remove waste
  • as water levels fall lungfish burrow into bottom mud and form a cocoon of their own secretion of mucus and aestivale (enter torpor) through the dry season and can hibernate for up to 2 years
277
Q

what are the 2 main types of extinct amphibians?

A
  1. osteolepiforms- up to 7m long, ambush predators. prehistoric lobe finned fish
  2. elpistostegids- panderichthys, 385MYA, no dorsal or anal fins, prehistoric lobe finned fish, eyes on top of hea, reduced tail, extensive downward facing ribs, dorsoventrally flattened body and head with long broad snout, more closely resemble tetrapods
278
Q

in amphibians what was evidence for the beginnings of tetrapod middle ear?

A

a different spiracular region

279
Q

what is tiktaalik?

A

extinct 383MYA

  • midpoint between osteolepiforms and tetrapods
  • fish but have features resembling tetrapods
  • large ribs
  • flexible pectoral fins
  • longer snout to snap up prey
  • reduced gill covers and reduced water flow through gills
280
Q

are the evolution of tetrapods and terrestrial life linked?

A

they are 2 separate events

281
Q

give 3 examples of how tetrapod features are advantageous to animals in water

A
  1. the frogfish- teleost that uses fish to move around substrate
  2. eel catfish- teleost with flexible neck to gain food from terrestrial environment
  3. mudskipper- uses fins to move on surface out of water and exploit terrestrial life
282
Q

what are 2 early tetrapod fossils?

A
  1. acanthostega- 8 toes on front and hind limbs
  2. ichthyostega- first tetrapods to leave water, 7 toes on hind feet, lateral line system, can breathe through skin, tibia fibula and first 2 rows of tarsal bones formed by preaxial radials, third row tarsal bones metatarsals and digits originate at postaxial branches
283
Q

what are fins homologous to?

A

limbs- they have the same genes for digit and rat formation but differential gene expression

284
Q

what is the reduction in digits in evolutionary lineages of birds and mammals associated with?

A

high speed running

285
Q

in what 2 ways can digits be lost ?

A
  • reduced gene expression of ptch1 (cattle and pigs)

- digit forms but cell death then occurs (horses, jerboas, camels)

286
Q

what evidence is there for convergent evolution of embryonic limb skeleton in multiple mammal species?

A

species such as horses and jerboas both lost digits due to cell death but they are unrelated so it must be convergent evolution

287
Q

what are the 2 main ancestral tetrapod groups?

A

batrachomorphs and reptiliomorpha (gave rise to amniotes) which both gave rise to urodela and anura

288
Q

give 7 changes from land to water and the response to it allowing for the transition

A
  1. increased solar radiation so need protection- chromatophores in skin absorb light rays
  2. less support and less resistance to movement- strong skeleton and musculature and lateral undulations in tailed amphibians
  3. light and sound waves travel differently in air so sense organs modified- fish like eye transformed in metamorphosis (lens flattened, eyelids and tear glands), evolution of eardrum
  4. air has lower thermal stability so temp varies- ectotherms have low metabolism, may hibernate or spend prolonged time in torpor
  5. O2 more abundant but gas exchange must have no water loss- skin vascularised, lungs primary site of gas exchange
  6. water limited so needs to be conserved- keratin and mucus in skin, live in damp places, excrete urea and some uric acid
  7. most return to water to breed, range of reproductive specialisation
289
Q

what are the 3 main groups of amphibians and when were the oldest fossils?

A

urodeles, anurans, caecilians

fossils: 290MYA permian showing urodele and anuran types

290
Q

give 10 features of urodeles

A

newts and salamanders

  • mostly 4 limbs
  • salamander body forms reflect differences in life histories and habitats
  • fish like undulations of trunk and tail to assist limb muscles in advancing and retracting limbs
  • 500 species
  • mostly internal fertilisation
  • spermatophores comprise a gelatinous base and sperm cap
  • variation in courtship display (can have elaborate secondary sexual characters
  • pheromone transfer by tail fanning in aquatic species or skin slapping, biting, rubbing in terrestrial species
  • mostly aquatic eggs and larvae (ovoviviparity in purely terrestrial species
  • paedomorphosis/neoteny (reproduction during larval stage)
291
Q

give 10 features of anurans

A
  • most diverse and widespread group of amphibians
  • lost tail
  • rigid body with well developed legs
  • african clawed frog fish like with lateral line system
  • body form evolved because of advantage in swimming with hind legs
  • diversity in body shape and lifestyle
  • around 25 subfamilies
  • all carnivorous
  • body specialised for jumping (fused urostyle and tibia/fibula, specialised muscles in hind legs)
  • highly modified skeleton
292
Q

where is the generalised amphibian life cycle common?

A

temperate regions

293
Q

what is 1 factor that has led to range of life history adaptations?

A

evolutionary trend towards transferring as many stages as possible to the terrestrial environment

294
Q

describe the trends in reproductive diversity in amphibians

A
  • predation pressures on land less than aquatic, requires convergent adaptation against desiccation
  • increasing egg and larval size enhances survival rate but trade off between producing fewer more costly eggs with longer developmental size or many eggs
  • often associated with many convergent modes of parental care
295
Q

what are foam nests?

A

produced by amphibians

  • secretions from oviduct
  • males and females produce them by movement of front/hind limbs
  • protects eggs from desiccation and predation
  • evolved independently and convergently within at least 6 phylogenetic lineages across all tropical continents
296
Q

where may amphibian eggs be laid?

A

on water overhanging leaves

  • tadpoles develop aquatically when fall into ponds
  • egg clutches sometimes folded into large leaves
  • can be accompanied with guarding of clutches by males
  • evolved independently in at least 3 groups
297
Q

describe different ways tadpoles may develop

A
  • some have terrestrial tadpole development
  • ovoviviparity so eggs and tadpoles develop in the female oviduct
  • embryos of 3 species are nourished with secretions
  • mouth brooding and stomach brooding can occur (R.darwinii frog)
298
Q

explain parental care in the poison arrow frog

A
  • males (2-3cm) have and defend territories of several hundred ,2
  • terrestrial egg clutches and tadpoles hatch from eggs
  • tadpoles climb on parents back and are transported to aquatic sites
  • males or females can be responsible for parental care
  • small, ephemeral water bodies are usually predator free and contain no food
  • some species feed tadpoles unfertilised eggs
299
Q

for reproduction how do frogs mainly communicate?

A
  • acoustic- sex pheromones play no/little role
  • nocturnal/crepuscular (active during twilight) so communicate acoustically
  • calls stereotypes with some species having different types of calls
  • calls can be produced by in or exhaling air on land or underwater
  • only males call
  • vocal sac amplifies calls, radiating call into circular directions
300
Q

what are the pros and cons of producing acoustic signals?

A

PRO: ease of signal variation, signals can go around obstacles, works in darkness, can adapt call rate and type depending on social contexts
CON: signals travel short distances and cover short time periods, attract predators as well as mates, costly to produce, social interactions in chorus can increase costs

301
Q

explain the experiment carried out to capture the cost of singing in frogs

A

tungara frogs

  • played song of whine and whine and chuck
  • females choose males that make more chucks
  • more extra males in pond the more chucks played
  • predation risk increases with number of chuck playbacks
  • chorus size increases, predation risk decreases so overall advantage to complex songs
302
Q

as well as acoustic signals how else can amphibian species communicate?

A

through leg waving such as in stream living frogs

303
Q

what are some comparisons that can be made between triassic anurans and modern day anurans?

A

modern:
more derived characters including shortening of body due to loss of vertebrae, elongated ilia, fusion of posterior vertebrae to form urostyle to support pelvic ilium, increased leg length to aid swimming and jumping

304
Q

what 2 bones in anurans are fusions and what do they act as?

A

tibio-fibula and radio-ulna

shock absorbers

305
Q

what is in the skin of anurans acting as a deterrent?

A

poison glands in skin

306
Q

give 11 features of caecilians

A
  • burrowing or aquatic
  • legless and blind
  • appear segmented but just folds of skin
  • 180 species , purely tropical
  • subterranean terrestrial life requires specialised reproduction
  • internal fertilisation, sperm transferred by adapted cloaca
  • egg laying or viviparous
  • females can give birth to up to 9 offspring and have up to 60% body length adults
  • energy for growing first supplied by yolk then mother (uterine milk secretions from walls of oviducts)
  • foetal gill for gas exchange across oviduct walls, can be exchange of metabolic waste
  • specialised foetal dentitions for scraping oviduct walls
307
Q

what are 6 shared derived features of amphibians?

A
  • smooth, moist, permeable skin
  • amphibian papilla in inner ear
  • operculum columella complex in ear
  • green rods in retina
  • pedicellate teeth (pedicle composed of dentine and separated by connective tissue)
  • levator bulbi muscle causes eyes to bulge forward
308
Q

what main line of diversification led to reptiles and birds ?

A

sauropsids

309
Q

what is an amniote and what are the 3 main extraembryonic membranes?

A

presence of amniotic egg
chorion= surrounds everything
allantois= nitrogenous waste deposited, vascularised and involved in gas exchange
amnion= surrounds embryo

310
Q

what does the albumin and shell do in the amniotic egg?

A

albumin surrounds everything as source of water and proteins, provides protection
shell surrounds egg and provides support

311
Q

what are 5 derived features of amniotes?

A
  • skin permeability (thicker, keratinised, more lipids, waterproof)
  • scales, hair, feathers (thickening of epidermis)
  • costal rib ventilation creates pressure difference to draw air in
  • longer neck
  • more complex nerves controlling forelimb so increased movement and dexterity
312
Q

what’s the difference between anapsid, synapsid, diapsid skulls?

A

anapsid- no arches
synapsid- 1 hole, 1 arch
diapsid- 2 holes, 2 arches

313
Q

did the ancestral sauropsida skull have holes?

A

no holes so diapsid condition must have developed convergently

314
Q

what type of skulls do these have?

a) sauropsids
b) turtles
c) non mammals
d) mammal
e) sphenodon
f) lizard
g) snake
h) dinosaur
i) bird

A

a) ancestral anapsid
b) modified anapsid
c) ancestral synapsid
d) derived mammalian synapsid with dermal bone surrounding braincase
e) ancestral diapsid
f) lower temporal bar lost
g) upper and lower bars lost
h) ancestral diapsid
i) convergent with mammal condition

315
Q

whats the difference between non amniote and amniote skull?

A

non amniote- flat skull and single muscle mass originates from braincase and underside of dermal skull roof
amniote- skull tall enough for jaw muscle to originate from top of head, muscles are attached through the holes and can bulge through allowing for more powerful jaws, have fenestra

316
Q

what are the 2 main groups of diapsids?

A

lepidosaurs- tuatara, snakes , lizards

archosaurs- crocodiles, dinosaurs, pterosaurs, birds

317
Q

when did archosaurs diverge from lepidosaurs?

A

permian

318
Q

give features of chelonia

A

turtles

  • fossils from 220MYA
  • most species withdraw neck into shell by bending it in vertical plane in s shaped loop
  • teeth lost over time
  • carapace has keratin on top and underneath is bone and is an extension of the ribs as they are fused to it
  • if muscles push gut downwards lung can contract
  • plastron has some bone in it but with keratin on the outside
319
Q

what migration behaviour does the herbivorous green turtle display?

A

migrates in carribean and south atlantic for feeding and reproduction
breed on ascension island but feed off coast of brazil
will return here year after year using olfactory cue to locate the sight (others use light, wave direction, magnetism)- development of hotels along coast confuse them

320
Q

what is the sex determination of turtles?

A

environmental sex determination and often temp dependent
- females are produced at higher temps
(but in lizards the males are produced at higher temp and usually the larger sex develops at the higher temp)

321
Q

what is the example of kemp’s ridley turtles

A

increase in proportion females from 1985 onwards after incubation temperatures raised

322
Q

give 6 features of tuatara/ sphenodon

A
  • spines on back
  • found in new zealand islands
  • diapsid skull
  • nocturnal and low body temp
  • mostly feed on invertebrates
    2 complete arches of bone
323
Q

what are squamates?

A

reptiles, lepidosaurs- lizards and snakes

324
Q

give features of lizards and 2 examples

A

small ones often insectivorous
larger ones often herbivorous
dwarf gecko 1.6cm
komodo dragon 3m (ambush predator with venom in saliva)

325
Q

explain limb reduction

A

evolved over 60 times and is associated with burrowing and living in vegetation
surface dwellers with long tails and burrowers with shorter tails

326
Q

give 10 features of snakes

A
  • specialised legless lizards
  • skull kinesis further increased by loss of upper temporal arch
  • branching from lizards in the cretaceous
  • very different eyes to lizards
  • change in gene expression leads to more thoracic vertebrae
  • reduction in limb development
  • lack pectoral and pelvic girdles
  • elongation reduces body diameter
  • flexible jaw
  • can wrap around prey stopping them from breathing by constricting blood flow to vital organs
327
Q

give 8 features of crocodilia

A
  • teeth in sockets (thecodont) which is convergent to mammals
  • diapsid skull
  • secondary palate separating nasal from oral cavity
  • sensory structures around mouth sensitive to movement and touch so can help young with their mouth
  • used to be more diverse and extensive
  • snout used to manipulate food
  • parental care and communication
  • eggs buried underneath the soil
328
Q

what are the 3 main ancient fossils of crocodilia?

A

P.kapilimari
D.andiniensis
S.clarki

329
Q

what group did birds evolve within?

A

archosaurs

330
Q

what 3 possible phylogenetic origins have been considered for birds and which was proven to be correct?

A
  1. direct descendents of crocodiles
  2. descendents of unknown group within archosaurs
  3. descendents of therapoda (small carnivorous dinosaur)- suggested by Huxley 1860 and was proven to be correct through phylogenetic analysis and fossil discoveries
331
Q

what is hugely conserved within theropod dinosaurs and what did theropod lineages undergo?

A

body size conserved- birds and relatives consistently small

lineages leading to birds underwent sustained miniaturization so body size decreased and specie evolved quicker

332
Q

around what time did the birds arise and what is the revised dinosaur evolutionary tree like?

A

early cretaceous

therapoda grouped with ornithischia (bird dinosaur) rather than as an outgroup)

333
Q

why is it hard to place bird dinosaurs on phylogenetic tree?

A

lot of branching that occured a long time ago and there are few fossils and limited data

334
Q

give 8 dinosaur features of birds

A
  • egg laying
  • scales
  • s shaped neck
  • tridactyl foot
  • bipedal
  • toes bearing weight of body
  • wishbone
  • fused sternum
335
Q

how many digits did ancestral bird forms have and how many do modern day have?

A

used to have 5 digits but now only 3- first digit reduced and the second and third fused

336
Q

why may dinosaurs have had feathers?

A

for display and colouration and perhaps insulation

337
Q

give 12 features of archaeopteryx including reptile and avian features it possesses

A
  • transitional form
  • paedomorphic skull
  • fossil with well developed feathers from mid-jurassic period 150MYA
  • first specimen found in germany 1860
  • few links to other groups
  • 12 individuals found
  • size of crow
  • opposable first toe
  • asymmetrical feathers evolve for flight
  • reptile features include: thick bones, toothed jaw, no fusion of vertebrate
  • avian features include: well developed feathers, three fingers, s shaped neck
338
Q

what does the wishbone have and when must it have evolved before?

A

fused clavicles but must’ve evolved before birds as theropods also have it

339
Q

how does the pigeon compare to archaeopteryx?

A

pigeon brain larger and can process visual stimuli, pelvis more developed

340
Q

what 2 ancient birds were around in the early/mid cretaceous?

A

mononykus- from mongolia, strange forelimbs and no flight ability

iberomesornis- spain, structural advances in forelimbs, ossified sternum and tail

341
Q

what 2 ancient birds were around in the mid/late cretaceous?

A

enantiornithes- most diverse group in cretaceous in almost all continents

hesperornis- n america

enaliornis- flightless sea birds, england

342
Q

in 1999 what did the national geographic announce?

A

discovery of missing link between birds and non bird dinosaurs archaeoraptor

343
Q

what is the most primitive known dromaeosaur?

A

microraptor

344
Q

when did modern birds diverge ?

A

about 150MYA

345
Q

within dinosaurs roughly how many times did flight evolve?

A

at least twice - birds and pterosaurs

346
Q

what is the ability of birds to fly linked to?

A

success as most diverse group of terrestrial vertebrates

347
Q

what are 5 pros to flight?

A
  • efficient way of foraging
  • cost effective way of locomotion
  • very fast locomotion
  • colonisation of remote habitat
  • migrations across planet for hibernation and aestivation
348
Q

what are 3 adaptation to deal with constraints of flight?

A
  • uniform in morphology compared to other classes of vertebrates
  • flying birds have limited size and weight range
  • muscle power needed to take off increases by factor of 2.25 for each doubling of biomass
349
Q

how many feather like forms do dinosaur fossils reveal ?

A

9

350
Q

what are the 2 theories for origins of avian flight?

A
  1. small theropods would run along ground and leap into air to pursue prey or escape predators
  2. arboreal theory- climb trees and glide down
351
Q

what is the WAIR theory?

A

wing assisted incline theory

  • could be earlier incarnation of arboreal hypothesis or combo of cursorial and arboreal
  • seen in some modern birds
352
Q

what is an alternative theory to the cursorial theory?

A

pouncing proavis hypothesis

- use wings to project and accelerate themselves at prey

353
Q

why until recently was it considered more likely flight evolved from cursorial stage where wings were used for prey capture?

A
  • ambiguous morphological evidence of climbing abilities
  • lack of trees in locations where archaeopteryx found
  • spread of feathered forelimbs to wings was originally for stabilisation during running
  • archaeopteryx could most likely glide but ability for flapping flight due to lack of flexible wings
354
Q

when were archaeopteryx flying and what does this mean for dinosauran flight?

A

150MYA- so dinosaurus flight must’ve evolved even earlier

355
Q

what are 3 problems with the cursorial origin of flight?

A
  • max running speed 2m/s but estimated min flying speed 6m/s so there’s a velocity gap
  • high energy demands of evolving flight as it is a fight against gravity
  • problem explaining origin of flight stroke in earthbound organisms
356
Q

what 2 pieces of evidence are there in favour of arboreal evolution?

A
  1. the hoatzin bird- lives in rainforest on leaves, evolved lysosome to digest cellulose, gut adapted to digest this, young hoatzin use claws to climb trees but they drop off when adult
  2. feduccias claw arc analysis- concluded archaeopteryx was an arboreal climbing bird that glided from heights, compared archaeopteryx
357
Q

what is the recent discovery in 2001 and 2002 for dromaeosaurs?

A

new specimens were discovered in western china which show forelimbs similar to archaeopteryx and hindlimbs similar to ancient arboreal birds but were feathered.

358
Q

in the late jurassic where did flight evolve?

A

in paravian theropod dinosaurs

359
Q

what 5 ancient birds show evidence of modern feathers?

A
caudipteryx
archaeopteryx
confuciusornis
enantiornithines
euornithes
360
Q

where did feathers first evolve and why?

A

theropods not birds and for stability rather than flying

361
Q

what are feathers most likely homologous to and what functions other than flight are they for?

A

homologous of reptilian scales

also for thermoregulation, colouration, waterproof dressing

362
Q

what are the 4 main components of feathers?

and what is their structure?

A

b-keratin (>90%), lipids (>1%), water (8%), pigments

hooks interlock on barbs creating strong vanes

363
Q

what are the 6 types of feathers in extant birds?

A

tail, flight, semiplume, down, filoplume, bristle

364
Q

what are remiges and rectrices?

A

wing feathers

tail feathers

365
Q

give the 7 main principles of flight

A
  • wings function as aerofoil/lift and propeller/forwards motion
  • shape, area, position can be modified
  • wings follow principle of cambered airfoil
  • bottom surface of wing pushes air forwards and down creating area of high pressure below the wing and low pressure above providing lift
  • increasing angle of attack increases lift by up to 15 degrees
  • small group of feathers called alula produce a slot in front of the airfoil to reduce turbulence
  • slots between feathers on wing tips reduce tip vortex
366
Q

what is cambered airfoil?

A

camber is the asymmetry of the wing with a convex dorsal side and concave ventral and increases maximum lift

367
Q

what are the 4 wing functional types and describe each as well as their aspect ratios and an example of each

A
  1. dynamic soaring- high aspect ratio (length:width) to make use of vertical wind gradient- shearwater
  2. elliptical- low aspect ratio, cambered, high maneuverability- pheasant
  3. high aspect ratio- little camber, low wing loading- swallow
  4. high lift wing- aspect ratio between 2 and 3, static soaring- rough legged hawk
368
Q

what movement are wing tips responsible for and what does this lead to?

A

thrust which leads to forward momentum at downward stroke through wings inclined from the horizontal plane

369
Q

in birds what is the pattern of air flow during inspiration and expiration?

A

unidirectional- higher O2 conc than mammals

air flows through peribronchial lung during both phases of respiratory cycle

370
Q

what are colours and patterns of wings important for? and what are colours a combinationof?

A

important for sexual selection and crypsis and are a combination of pigment and structural characteristics- reflect specific wavelengths depending on pigment particle size

371
Q

what are the 4. main pigments?

A

eumelanins: black/grey
pheomelanin: red/brown
carotenoids: red/yellow
porphyrins: UV sensitive

372
Q

what is iridescence?

A

interferences of reflections from many layers of melanin platelets so the colour can change if viewed from different angles

373
Q

are feathers and flight older than birds?

A

most likely as is evidence for 4 limb flying

374
Q

which synapsids were the most common?

A

permian and carboniferous

375
Q

why did number of mammals increase?

A

increase in flowering plants and insects as a food source

376
Q

what did the ascendancy of dinosaurs almost do?

A

almost annihilated synapsid groups

377
Q

what are the 3 main groups that eventually led to mammals called and give features of each

A
  1. pelycosaurs- basal amniotes with body and leg undulations used and undifferentiated teeth
  2. therapsids- more derived, holes in skull larger, larger canines, limbs more underneath body, decreased size
  3. cynodonts- changes in skull and skeleton, decreases size, more upright limbs
378
Q

describe mammal-like reptiles/non mammalian synapsids

A
  • homodont teeth
  • other bones pushed back eventually becoming part of middle ear
  • zygomatic arch/cheekbone develops
  • jaw bone becomes prominent in lower jaw changing articulation of skull
379
Q

what’s the difference between early amniotes and modern mammals in terms of limb orientation?

A

early amniotes have the same muscles for movement and breathing so hard to do at the same time
BUT: mammals have limbs more underneath the body, lungs compress to push air out, when stretch out -ve pressure in lung draws air in, thorax and legs separate so can breathe and move at the same time

380
Q

what are 6 features of. early mammals and give 3 more general features of mammals

A
  • small and insectivorous
  • egg laying
  • nocturnal and solitary
  • infant/mother bond strong
  • large olfactory bulbs
  • lots of rods in retina good for low light concentration

endothermy, lactation and suckiling, hair for insulation

381
Q

describe the teeth sets of most mammals and how it could have evolved

A

diphyodont (2 sets) with precise occlusion to improve grinding surface- but is not possible to have precise occlusion in polyphyodont so diphyodont must have preceded precise occlusion
- evolved as animals fed on milk early in life so didn’t need permanent teeth until later

382
Q

whats the jaw structure and molars of most mammals like?

A

lower jaw narrower than upper so it can move from side to side
- has premolars and more complex molar with upper and lower offset so occlusion can occur

383
Q

how did lactation evolve?

A

mammary glands are related to apocrine hair glands
originally aggregating pheromones secreted
milk may have been produced to protect eggs from desiccation and microbes
evolved as nutritious secretion

384
Q

what is the evolutionary advantage of lactation?

A
  • production of offspring is separated from seasonal food supply
  • mother not dependent on paternal care
  • makes viviparity less strenuous on mother
385
Q

describe suckiling

A

giving milk and is unique

  • there are tight seals in pharynx preventing fluids entering lungs and stomach in an uncontrolled way
  • seals separate breathing and swallowing
386
Q

what are facial muscles homologous to?

A

neck constrictor muscles of reptiles

387
Q

what are prototheria and give 2 features and 3 examples

A

monotremes

  • mammals that lay eggs/oviparous and feed their babies milk
  • monotreme refers to common rear opening (cloaca)used for reproduction and excretion
  • platypus and spiny anteater and echidna
388
Q

what are 3 monotremes and when did they diverge from each other?

A

duck billed platypus, short nosed and long nosed echidna

echidna and platypus diverged 19-48mya

389
Q

how many electrical receptors do platypus have in their bill?

A

40,000

390
Q

what are the 2 groups of theria?

A

metatheria (marsupials) and eutheria (placentals)

391
Q

in what 6 ways do metatherian mammals differ from eutherian?

A
  • usually opposable digit on hind foot
  • more incisors and molars but fewer premolars
  • bifurcated reproductive tract, simple placenta in some species, pouch/marsupium present in 50% species
  • altricial young with 1% body mass
  • lower body temp and basal metabolic rate
  • smaller relative brain size
392
Q

where are modern day marsupials present?

A

S.America and Australia

393
Q

whats the difference between non-syndactylous and syndactylous?

A

non syndactylous have 4 independent digits but syndactylous have digits 2 and 3 fused together

394
Q

whats the difference between polyprotodont and diprotodont ?

A

poly: multiple incisors
dipro: 2 lower incisors

395
Q

what families are included in order diprotodontia?

A

possums, koalas, cuscuses, kangaroos, wallabies, wombats, glider, rat kangaroo,

396
Q

what families are included in order dasyuromorphia?

A

antechinuses, quolls, dunnarts, tasmanian devil, numbat

397
Q

what families are included in order notoryctemorphia?

A

marsupial mole

398
Q

what families are included in order peramelemorphia?

A

bilbies, bandicoots

399
Q

what families are included in order microbiotheria?

A

monito del monte

400
Q

what families are included in order paucituberculata?

A

shrew opossums

401
Q

what families are included in order didelphimorphia?

A

opossums

402
Q

describe marsupial evolution

A
  • Australia split from Antarctica 45MYA
  • S.America split from antarctica 30MYA
  • marsupials split from eutherian mammals around 100MYA
  • when land bridge opened between north and south america placentals moved from N to S and marsupials moved from S to N
  • australia isolated location with only marsupials
403
Q

what happened at the KT boundary?

A

possibly a meteorite strike so extinction occurred and approx 50% all genera became extinct including non avian dinosaurs
caused a much colder climate and many groups wiped out

404
Q

when did marsupials and mammals diverge?

A

100mya

405
Q

when was the basal split among marsupial orders?

A

80mya

406
Q

what is the Wallace line?

A

geographical division in SE Asia

SE of the line is where marsupials occur and placentals north of it

407
Q

in terms of females what is marsupial reproduction?

A
  • pouch/marsupium in 50% species
  • paired vaginal transport system
  • birth via pseudovaginal canal
  • 2 uteri
  • simple placenta
  • highly altricial young with short gestation
  • can have new born attached to nipple or fertilised blastocyst in uterus
  • similar oestrus cycle to eutherians, controlled by same hormones
408
Q

in terms of males what is marsupial reproduction?

A
  • combined urogenital tract in males and females, cloaca
  • scrotum cranial to penis
  • bipartite penes
409
Q

what are the costs of being a placental?

A
  • can’t off load embryo, long gestation
  • female structure has to be altered for birth, birth canal and wider pelvis
  • placentals had to develop trophoblast to protect embryo
410
Q

what are costs of being marsupial?

A
  • restriction of forelimb development

- reduced brain size, opportunity to learn by observation

411
Q

give an example of convergence in an arboreal mammal community?

A

lemurs and opossums

  • similar historical biogeography
  • similar habitats of rainforest
  • comparable diets
  • similar size
  • both have low fecundity with 1-2 young per year
  • similar general behaviour
412
Q

give an example of diet convergence

A

striped possum and aye aye possum both have an extended finger for extracting insect larvae from rotten wood

413
Q

give an example of gliding convergence

A

squirrel gliders (order diprotodontia) and flying squirrels (order rodentia)

414
Q

how many species does the IUCN list as being of concern in Australasia and why may the extinctions have occurred?

A

> 200 species
colonisation by aboriginal humans
when europeans reached Australia and South America and when north American eutherians invaded

415
Q

in Australia what is the critical weight range for animals?

A

35g-5kg

416
Q

define ectothermy?

A

depending on external sources for body heat

417
Q

define poikilothermy?

A

organism whose internal temp varies considerably`

418
Q

define homeothermy?

A

any animal that retains entirely stable internal temp under normal conditions

419
Q

define endothermy?

A

generation of heat and regulation of body temp metabolically

420
Q

are all homeotherms ectotherms?

A

no- all ectotherms are homeotherms though

421
Q

animals need a source of heat which usually flows from the body to the environment, where do ectotherms and endotherms get this heat?

A

ecto- from sun and contact with rocks

endo- from chemical reactions of metabolism

422
Q

give 6 points about ectothermy

A
  • heat body by basking
  • ancient but successful strategy
  • very high energy efficiency 50%
  • food energy available to increase biomass
  • very low energy requirements
  • ecological consequences: limit to where can live
423
Q

give 7 points about endothermy

A
  • heat body using metabolism
  • derived state (evolved twice in birds and mammals)
  • low energy efficiency (1% energy available for biomass increase)
  • high energy requirements
  • temp independent of environment so wider range of habitats
  • need more food
  • can exploit more niches
424
Q

what does metabolic rate increase with and who is heat loss higher for?

A

increases with decreasing body size

higher for smaller animals due to an increasing sa/v ratio

425
Q

why may you not see small endotherms?

A

sa/v ratio so high that they cannot eat enough food to maintain body temp

426
Q

are ectotherms or endotherms generally smaller?

A

ectotherms

427
Q

do you see tubular or flat mammals/birds?

A

no as this shape would loose heat too quickly

428
Q

describe how desert tortoises can increase their biomass?

A

eat hardly anything and spent most of the day and year inactive but can increase biomass by 25% each year- by tolerating severe imbalances in energy, water, ion budgets

429
Q

describe the energy budgets of ectotherms and what they lack

A
  • use burrows to thermoregulate
  • lack salt glands and kidneys so can’t produce concentrated urine so can’t excrete salt without losing lots of water
  • so retain salt and are osmotically stressed
  • means are tolerant different degrees of osmotic pressure
430
Q

what do desert animals rely on to escape the heat and cold?

A

temp differences between sunlight and shade and surface and underground burrows

431
Q

give 2 examples of how ectotherms show behavioural and physiological adaptations for temperature regulation

A

desert iguana- changes colour throughout day to alter absorption
marine iguana- minimises surface area exposed to sun and creates a convective current

432
Q

what may tadpoles in the desert do when stuck in water bodies?

A

move around to cope with the different temperatures

cluster where cool water in midday and in the evening cluster in the middle where warm

433
Q

describe the efficiency of the garter scale activity in relation to body temp

A

as body temp increases the efficiency increases until a peak point but O2 consumption also increases

434
Q

in what 2 ways can ectotherms cope with very low temperatures?

A
  1. freeze avoidance- contact with ice means risk of freezing so surface dwellers produce antifreeze and deep water fish can become supercooled
  2. tolerate freezing- cells not completely frozen due to protection of cryoprotectant in cell in response to freezing, cells maintain low levels of aerobic activity, wood frogs can survive freezing in sub zero temps in arctic circle
435
Q

what is…

a) thermoneutral zone
b) evaporative cooling
c) hyperthermia
d) metabolic heat production
e) hypothermia

A

a) between upper an lower critical temp
b) above upper critical temp
c) above upper lethal temp
d) below lower critical temp
e) below lower lethal temp

436
Q

what are endomesothermic sharks?

A

high body temp mean can swim faster and further can catch more prey

  • heat generating muscles heating up to 20c warmer than water temp
  • lamnidae sharks and tuna
437
Q

what is the migration of fish with endothermy like ?

A

larger maximum annual migration range that ectothermic fish

438
Q

what is opah?

A

lampris guttatus- first warm blooded endothermic fish

439
Q

is growth rate higher in endotherms or ectotherms?

A

endotherms

440
Q

wet fur is a poor insulator so what do aquatic mammals use to conserve heat?

A

blubber

441
Q

what is torpor?

A

adaptive hypothermia or temporary hibernation

  • body temp falls, metabolic rate reduced, slow respiration, reduced heart rate
  • smaller animals have more to gain from torpor as harder to keep body warm
  • larger bodies take longer and require more energy to warm up again
442
Q

describe endotherms in the desert

A
  • heat gradient reversed: heat flows from environment to animal
  • harder than coping with extreme cold
  • use evaporation to cool but is risk of dehydration
443
Q

what’s the difference between a dehydrated camel and one that has daily access to water?

A

dehydrated relaxes its control of body temp

444
Q

how many species of primates, where restricted to, what do most eat and when was the earliest known primate?

A

250
tropical regions
omnivores some leaf eaters with cellulose fermentation
55MY old

445
Q

what are the 4 divisions of primates?

A
  1. prosimians: basic primates- lemurs, bush babies
  2. new world monkeys/ Ceboidea - marmosets, tamarins, spider monkey
  3. old world monkeys (cercopithecoidea)- baboons, langurs
  4. apes, hominids, humans (hominoid)- lesser apes, great apes, humans
446
Q

give 11 characteristics of primates

A
  • retention of clavicle
  • shoulder joint allows for limb movement in all directions
  • elbow joint permits rotation of forearm
  • 5 digits on fore and hind limbs
  • usually one young per pregnancy
  • reduced snout
  • reduced number of teeth
  • claws modified into flattened nails
  • large barin
  • not all features in basal members
  • most features attributed to arboreal lifestyle
447
Q

whats the difference between strepsirhini and haplorhini?

A

strep- wet noses: tarsiers and prosimians

hap- dry noses: all other primates

448
Q

give 9 characteristics of strepsirhini

A
  • usually small and nocturnal
  • long snouted
  • skull has an unfused frontal and symphysis and lack of postorbital closure
  • lemurs are native to Madagascar
  • long rostrum
  • postorbital bar
  • temporal fossa
  • no plate
449
Q

give 2 characteristics of haplorhini

A
  • relatively short rostrum

- plate separating orbits from temporal fossa

450
Q

what does catarrhini comprise?
and which od the two is more specialised and species rich?
and how many premolars?

A

old world monkeys and apes
- old work monkeys
2 premolars

451
Q

what are the 2 subdivisions/subfamilies of Catarrhini/old world monkeys

A

colobines

cercopithecines

452
Q

give 4 features and 2 examples of colobines

A
  • in African and Asia
  • folivorous with complex fore stomach
  • arboreal with handles longer than forelimbs and long tails
  • stub thumbs
  • colobus
  • grey langur
453
Q

give 3 features and 3 examples of cercopithecines

A
  • africa
  • omnivorous
  • increasingly terrestrial with short tails and limbs equal length
  • cercopithecine
  • Diana monkey
  • baboons
454
Q

give 3 general characteristics of new world monkeys/platyrrhini and what are the 3 subdivisions?

A
  • 3 premolars
  • colonised S.America across Atlantic about 30 MYA by boat
  • no radiation into terrestrial or ape like forms
  • cebines, callitrichines, atelines
455
Q

give 2 examples of cebines

A

squirrel monkey and capuchin monkey

456
Q

give 2 examples and 2 characteristics of callitrichines

A
  • marmosets
  • lion tamarin
  • secondary claws
  • produce twins
457
Q

give 2 characteristics and 1 example of atelines

A
  • specialised climbers
  • prehensile tail
  • spider monkeys
458
Q

give 5 characteristics of hominoidea

A
  • broad thorax and dorsal position of scapula assist balance in bipedal pose with centre of gravity near vertebrate column
  • caudal vertebrae reduced
  • frontal skull characterised by sinuses
  • 5 cusps on molars (OW monkeys have 4 so can tell them apart)
  • critically endangered
459
Q

give group size, no. of males in group, male behaviour and examples for each of these systems:

a) female transfer
b) male transfer
c) monogamous
d) solitary

A

a) small, one or many males, territorial and so empties kinship groups, chimp gorilla baboons colobus
b) large, one or several, male hierarchy, most cercopithecines
c) 1 family, one, both sexes for defence and parental care, gibbons and tamarins
d) individual or female and offspring, no males, hushbabies orang-utans

460
Q
  1. what has a dog like snout?
  2. where do downward nostrils appear?
  3. which groups have a tail and which species has prehensile?
  4. which groups have callosities?
  5. which have longer rear limbs than forelimbs?
A
  1. lemur
  2. OW moneys, lesser apes (Hylobatidae) and pongidae
  3. lemurs, NW monkeys, OW monkeys, spider monkey prehensile
  4. OW monkeys and lesser apes
  5. lesser apes and pongidae
461
Q

whats included in pongidae and are males or females larger?

A

orang-utan, gorilla, chimpanzee, human

males larger

462
Q

what kind of vision did the ancestral vertebrate have?

A

tetra chromatic with 4 types of cone cells can see UV

463
Q

what are the 3 types of colour vision?

A
  1. dichromacy (red/green colour blind)
  2. routine trichromacy (OW and howlers)
  3. allelic trichromacy (NW- individuals of same sex and species can differ and is frequency dependent advantage)
464
Q

what allows colour to be seen and what is colour vision?

A

cone cells in retina contain photopigments called opsin that see colour colour vision is the ability of an organism to distinguish objects based on wavelengths or frequencies of light they reflect emit to transmit

465
Q

in primates what are the signals not?

A

not pooled so genetic mutations can lead to new colour signals- lots of cone cells connected to single nerve fibre

466
Q

how many opsin do most mammals such as dogs have and how does this compare to humans and birds and fish?

A

2
humans- 3
birds and fish- more

467
Q

where is the short wave opsin coded for? and where are the medium and long wave opsin coded?

A

short- on chromosome 7

medium and long- X chromosome

468
Q

give 4 features of dichromacy/colour blindness

A
  • most NW monkeys
  • gene for small (s) opsin located on chromosome 7
  • gene for L opsin on x chromosome
  • similar to red green colour blindness in humans
469
Q

explain the example of male squirrel monkeys with S and M opsin who were given gene therapy to introduce human L opsin

A

15-36% cells that were M opsins took up new opsin glen and expressed it, shifting preference to a longer wavelength
in less than a year they could discriminate between red and green and blue and yellow

470
Q

give 3 features of routine trichromacy

A
  • in all Catharrhini (OW monkeys, apes, humans) and howler monkeys
  • L opsin gene on x chromosome undergone duplication and the 2 copies evolved into M and L
  • all trichromatic as inherit autosomal S opsin as well as 2 different x genes
471
Q

describe the evolution of trichromacy ant he case of the howler monkeys

A
  • genetic dating of opsin genes infer that gene duplication responsible for routine trichromacy occurred at separation of platyrrhine and catarrhine primates
  • howler monkey routine trichromacy evolved more recently
  • translocation may have occurred
472
Q

give features of polymorphic trichromacy

A
  • some NW monkeys and some prosimians
  • only 1 copy but multiple alleles of L opsin gene on x chromosome
  • heterozygote females acquire different opsin from each copy of x chromosome
  • different x linked opsin alleles in heterozygous female expressed in different cone by random x chromosome inactivation
  • homozygote females and all males colour blind
  • thought to be 3 alleles for L gene in NW monkeys leading to 3 types of polymorphic trichromacy
  • 50-66% females usually trichromatic
  • may have persisted in NW monkeys due to benefits to a group of both trichromatic and dichromate
473
Q

what does it mean for a group having different alleles adapted to different wavelengths?

A

if in the same species can have both dichromatic and trichromatic females

  • dichromats: more frantic foraging, touch, sniff and bite more fruit
  • trichromats: make fear mistakes, forage more leisurely
474
Q

what can dichromats distinguish and how may this benefit?

A

distinguish patterns based on light that are invisible to trichromats- suggests better at spotting camouflaged predators or prey

475
Q

what must the maintenance of trichromacy be due to?

A

selective advantage

476
Q

describe fruit vs leaves in terms of dichromate and trichromacy

A
  • ripe fruit often red but also reflects light in blue/yellow range which can be seen by dichromats
  • young leaves have red colouration so can be seen by trichromats but reflect similar blue/yellow signal to old leaves
  • in OW many fruits produced seasonally (must turn to young leaves when no fruit)
477
Q

what is the most folivorous monkey in NW?

A

enforcing need for routine trichromacy

478
Q

did coloration of monkeys evolve before or after trichromacy?

A

after as trichromatic have more skin showing than dichromates