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Flashcards in 4 Deck (44)
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1
Q

What is a species?

A

A group of organisms that can interbreed and produce fertile offspring

2
Q

What is a habitat?

A

The environment in which a species normally lives or the location of a living organism

3
Q

Population

A

A group of organisms of the same species who live in the same area at the same time

4
Q

What is a community?

A

A group of populations of the same area living and interacting with each other

5
Q

What is an ecosystem?

A

A community and its abiotic environment

6
Q

What is ecology?

A

The study of relationships between living organisms and their environment

7
Q

What is an autotroph?

A

An organism that synthesises its organic molecules from simple inorganic molecules

8
Q

What are heterotrophs?

A

An organism that obtains organic molecules from other organisms

9
Q

What is a consumer?

A

An organism that ingests other organic matter that is living or recently killed

10
Q

What is a detrivore?

A

An organism that ingests non-living organic matter, a decomposer

11
Q

What is a Saprotroph?

A

An organism that lives in or in non-living organic matter, secreting digestive enzymes and absorbing products of digestion

12
Q

What is a good chain?

A

A representation of the relationships between organisms based on their diet

13
Q

What does a food web show?

A

How food chains are linked together in to more complex feeding relationships

14
Q

How is sunlight converted to chemical energy?

A

Sunlight is trapped by the protein chlorophyll through photosynthesis and converted to chemical energy

15
Q

Why is there energy loss between trophic levels?

A

Material is not consumed, which is used by saprophytes it respiration, but ultimately lost as heat to the environment, or it is assimilated and lost

16
Q

How much energy is assimilated at the next higher trophic levels?

A

10-20%

17
Q

What effect do extreme environments have impacted food chains?

A

In the Arctic, initial trapping of energy by producers is lower so the energy transfer to large predators is rare and food chains are shorter. In the rainforest trapping of energy by producers is more efficient so the food chains are longer and more complex

18
Q

What do pyramids of energy show?

A
  • shows flow of energy from 2 trophic level to the next
  • the decrease in shape as it goes upwards shows the gradual loss of energy
  • shows biomass of organisms
19
Q

How do producers recycle nutrients?

A

Producers take organic molecules and convert them into organic compounds, which consumers feed on

20
Q

How are nutrients recycled?

A
  • Producers take organic molecules and convert them into organic compounds
  • consumers take in this organic matter by feeding and use it for growth
  • decomposition begins when saprotrophic bacteria and fungi secrete extra cellular digestive enzymes into dead organisms, which are hydrolysed and reabsorbed by saprophytes
21
Q

What pools are carbon found in?

A
  • biosphere
  • oceans
  • atmosphere
  • sediments
22
Q

In which processes does carbon move between pools in?

A
  • photosynthesis
  • respiration
  • feeding
  • fossilisation
  • combustion
23
Q

How does carbon move in photosynthesis?

A

It moves by terrestrial and algae in which atmospheric and dissolved carbon is removed and fixed as carbon compounds, such as carbohydrates, lipids and proteins

24
Q

How does carbon move in feeding?

A

Carbon of organic molecules move from one link in the food chain to another

25
Q

How is carbon moved in fossilisation?

A

Carbon as organic molecules, becomes trapped in sediment as coal, gas and oil

26
Q

How is ATP produced?

A

By cell respiration

27
Q

What type of reaction is cell respiration?

A

Exothermic

28
Q

What happens as ATP is produced in cell respiration?

A

Carbon compounds are oxidised but are not immediately usable but ATP is as it is used in cell activities

29
Q

What is the mean concentration of CO2 in the atmosphere?

A

0.039%

30
Q

What happens to CO2 I’m solution?

A
  • CO2 is soluble in water
  • it either remains as dissolved has or combines with water to form carbonic acid
  • this can dissociate to form hydrogen and hydrogen carbonate ions (H+ and HCO3-
  • this reduces the pH of water
31
Q

How is CO2 absorbed?

A

It diffuses from atmosphere or water into autotrophs and photosynthesis reduces the concentration of CO2 in autotrophs, setting up a concentration gradient between the biotic and the abiotic. In leaves CO2 diffuses through the stomata on the underside of leaves. In aquatic plants the entire of the leaves and stem is permeable to CO2.

32
Q

How is methane produced?

A

It is produced from organic matter in anaerobic conditions by methanogenic archaens and diffuses into the atmosphere

33
Q

What is the concentration of methane in the atmosphere?

A

1.7-1.85 mmpm

34
Q

How is methane removed from the atmosphere?

A

Molecules of methane persist in the atmosphere for 12 years and and naturally oxidised in the stratosphere, and monatomic oxygen and highly reactive hydroxyl radicals are involved.

35
Q

How is peat formed?

A

In some environments water is unable to drain from soil producing anaerobic conditions that saprotrophs can’t survive in, and therefore there is no decomposition and acidic conditions develop.

36
Q

What percentage of the earths surface is peat?

A

3%

37
Q

How are fossils formed in limestone?

A
  • animals, such as reef building corals and molluscs have hard parts composed of calcium carbonate
  • when dead the decompose quickly
  • in acidic conditions, calcium carbonate dissolves away, in neutral or alkaline conditions it is stable and deposits form in the sea bed
  • in shallow, tropical seas, calcium carbonate is deposited by precipitation in water on limestone rock and animals are visible as fossils
38
Q

What percentage of all sedimentary rock is limestone?

A

10%

39
Q

What is the enhanced greenhouse effect?

A

The idea that humans are increasing the levels of CO2 and other greenhouse gases, which leads to climate change

40
Q

What are greenhouse gases?

A

Gas molecules in our atmosphere with 3 or 4 more atoms that can capture outgoing infrared energy and warm the planet

41
Q

What do increased greenhouse gases mean?

A

More infared light will be absorbed and scattered and retained as heat

42
Q

What does the precautionary principle say?

A

It says that if the effects of a human induced change that would be very large then those responsible must prove that it will do no harm before proceeding. If it is not proven that no harm will come, it must not go ahead

43
Q

What are effects of the greenhouse effects?

A
  • higher frequency and intensity of droughts
  • flooding due to higher rainfall
  • declines in food production
  • increased disease as higher temperature causes more pathogens
  • more extreme weather
  • loss of biodiversity
44
Q

What are consequences of the greenhouse effect on arctic ecosystems?

A
  • detritus is released from a permafrost state which leads to huge releases of methane and CO2, which was previously locked away
  • more areas with soul rich in humus are formed, causing more plant life to grow, absorbing radiant heat energy and contribute to global warming
  • Extensive flooding in low lands
  • there is a greater number of predators on expanding vertebrate populations