Lecture 12 Flashcards Preview

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Flashcards in Lecture 12 Deck (85)
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1
Q

What three groups of ecdysozoans are worm like marine animals?

A

Priapulids
Kinorhynchs
Loriciferans

2
Q

What are priapulids?

A

Unsegmented, three part body plan, burrow in soft sediment marine animals

3
Q

What do priapulids eat?

A

Soft body invertebrates such as polycheates

4
Q

How do priapulids eat?

A

Capture prey with a toothed, muscular parynx that is everted through their mouth

5
Q

What are kinorhynchs?

A

Microscopic marine animals that live in marine sands and muds

6
Q

How many segments are kinorhynchs bodies divided into?

A

13- each with a separate cuticular plate

7
Q

What happens to the cuticular plates of each segment of kinorhynchs as they grow?

A

They are periodically molted

8
Q

How do kinorhynchs feed?

A

Ingesting sediment through their retractable proboscis, digesting organic matter

9
Q

What are loriciferans?

A

Small animals less than 1mm

10
Q

What is the structure of loriciferans bodies?

A

Divided into head, neck, thorax, abdomen, covered in 6 plates

11
Q

Where do loriciferans live?

A

Course marine sediments

12
Q

What do loriciferans eat?

A

Not much is known, but some eat bacteria.

13
Q

What are horsehair worms?

A

Very thin, upto 2m long, freshwater worms

14
Q

What are horsehair worm larvae?

A

Internal parasites of insects and crayfish

15
Q

How do horsehair worms feed?

A

Many feed only as larvae
Others grow and moult by absorbing nutrients from the environment
Adult has no mouth and reduced nonfunctional gut

16
Q

What gives the unsegmented body of nematodes its shape?

A

A thick, multilayerd cuticle

17
Q

How many times does a nematode shed its cuticle?

A

4 times

18
Q

How do nematodes exchange oxygen and nutrients with their environment?

A

Through their cuticle and the gut

19
Q

How are materials moved through the gut of nematodes?

A

Rhythmic contraction of a highly muscular organ called the pharynx at the anterior end

20
Q

How do nematodes move?

A

By contracting their longitudinal muscles

21
Q

What soil inhabiting nematode is used as a model organism in labs?

A

Caenorhabitis elegans

22
Q

Why is Caneorhabitis elegans used as a model organism?

A

Because it is easy to cultivate, matures quickly and has a fixed number of body cells, its genome has been mapped.

23
Q

What do nematodes eat?

A

Many are predators- feed on protists and other small animals such as roundworms

24
Q

What diseases do nematodes cause in humans?

A

Trichinosis, filariasis, elephantiasis

25
Q

What do arthropods all have?

A

Limb like appendages

26
Q

What are some features of arthropods that made them successful?

A

Segmented bodies
Muscles attached to the inside of rigid exoskeletons
Segments have muscles and jointed appendages

27
Q

What do jointed appendages do?

A

Permit complex movement

Specialized for different functions

28
Q

What does encasement within an exoskeleton do?

A

Provide the animal with support for walking, protection from predators.

29
Q

How do arthropods not dry out in dry air?

A

Chitin provides waterproofing

30
Q

What are 4 major arthropod groups?

A

Crustaeceans, hexapods, myriapods, chelicerates

31
Q

Arthropods constitute a ________ group

A

Monophyletic

32
Q

What group was debated to be more closely related to annelids or arthropods?

A

Onychophorans (velvet worms)

More close to arthropods

33
Q

Where do onychophorans live?

A

Leaf litter in humid, tropical environments

34
Q

What bodies to onychophorans have?

A

Soft, segmented, covered in thin flexible cuticle containing chitin

35
Q

What are water bears called?

A

Tardigrades

36
Q

What bodies to tardigrades have?

A

Fleshy, unjointed legs

Fluid filled body cavities are hydrostatic skeletons

37
Q

Where do tardigrades live?

A

Marine sands

Temporary water films on plants

38
Q

Where did jointed legs first appear?

A

Trilobites- disappeared in the great permian extinction

39
Q

What are the dominant marine arthropods today?

A

Crustaeceans

40
Q

Name some crustaceans.

A

Shrimps, lobsters, crayfishes, crabs (decapods)
Sow bugs (isopods)
Copepods

41
Q

What are some unusual crustaceans that are sessile as adults?

A

Barnacles

42
Q

What are the 3 main regions of a crustaceans body?

A

Head
thorax
abdomen

43
Q

How many appendages do crustaceans head bear?

A

5 pairs

44
Q

What is the name of a fold of exoskeleton in some crustacean species that extends dorsally and laterally back from the head to cover and protect some segments?

A

The carapace

45
Q

What happens to ferilized eggs of crustaceans?

A

They are attached to the outside of the females body during early development

46
Q

What name is given to crustacean larvae?

A

Nauplius

47
Q

How many eyes and appendages do crustacean larvae have?

A

One eye

3 pairs of appendages

48
Q

What are insects?

A

6 legged hexapods

49
Q

What regions of body do insects have?

A

Head, thorax, abdomen

50
Q

What are some features of insects?

A

Gas exchange system made from trachea and spiracles
Single pair of antennae on the head
Three pairs of legs attached to thorax

51
Q

How are insects different to other arthropods?

A

They have no appendages from their abdominal segments

52
Q

Who decided there are more insects?

A

Terry Erwin

53
Q

What did terry erwin do?

A

Sample beetles in the canopies of a single rainforest tree, Lueha seemanni

54
Q

What are wingless relatives of insects called?

A

Springtails, two-pronged bristletails and proturans

55
Q

How can insects be distinguished from other hexapods?

A

External mouthparts and paired antennae that contain a sensory receptor

56
Q

What name is given to the sensory receptor in the antennae of insects?

A

Johnston’s organ

57
Q

What name is given to immature stages between moults of pterygote insects?

A

instars

58
Q

What type of metamorphosis do butterflies have?

A

Complete metamorphosis

59
Q

What is another type of metamorphosis?

A

incomplete metamorphosis- where changes are gradual

60
Q

What name is given to the specialized phase in which a caterpillar transforms to a butterfly?

A

pupa

61
Q

What insects were the first animals to achieve the ability to fly?

A

Pterygote insects

62
Q

How did flight cause the unparalleled evolutionary success of insects?

A

New lifestyles opened up, feeding opportunities only insects could exploit

63
Q

What wings do most adult flying insects have?

A

2 pairs of stiff, membranous wings attatched to the thorax

64
Q

What wings do true flies have?

A

Just one pair

65
Q

What wings to beetles have?

A

Forewings are heavy, hardened wing covers

66
Q

What two groups of pterygote insects cannot fold their wings back against their bodies?

A

Mayflies
Dragonflies
This is the ancestral condition

67
Q

What name is given to all other pterygote insects that can fold their wings against their bodies?

A

Neopterans

68
Q

How do many neopteran groups acquire adult organ systems such as wings and compound eyes?

A

Gradually, through several juvenile instars

69
Q

What is a new major group of neopterans?

A

Mantophasmatodeans- described in 2002

70
Q

What subgroup of neopterans has complete metamorphosis?

A

Holometabolus neopterans

71
Q

How does the time at which insects separated from the lineage leading to current crustaceans lead to their success?

A

hexapods penetrated an environment that lacked other similar organisms

72
Q

What evidence suggests that insect wings evolved from a dorsal branch of a crustacean-like limb?

A

Homologous genes control development of insect wings and crustacean appendages

73
Q

What two body regions do myriapods have?

A

A head and a trunk

74
Q

What do centipedes and millipedes have?

A

head

long, segmented flexible trunk with many pairs of legs

75
Q

How many pairs of legs to centipedes have per segment?

A

one pair

76
Q

What do centipedes eat?

A

Prey on insects and other small animals

77
Q

How many pairs of legs do millipedes have per body segment?

A

2 pairs

78
Q

What do millipedes eat?

A

They scavange and eat plants

79
Q

How many pairs of legs do chelicerates have?

A

4 pairs

80
Q

What are the three clades of chelicerates?

A

Pycnogonoids
Horseshoe crabs
Arachnids

81
Q

What are pycnogonoids?

A

Sea spiders, some eat algae, most are carnivorous

82
Q

How many living species of horseshoe crab are there?

A

4

83
Q

Where are horseshoe crabs common?

A

Shallow waters along eastern coasts of North America and southern and eastern coasts of Asia

84
Q

What disease are mites vectors for?

A

Rye mosaic disease- cause mange in domestic animals and skin irritation in humans

85
Q

What 6 factors effected diversity of protostome evolution?

A
Segmentation
Complex life cycles
Parasitism
Diverse feeding structures
Predation
locomotion