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Biology 21st century > Life on earth > Flashcards

Life on earth Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

What is the definition of a species?

A

A group of organisms that can breed together to produce fertile offspring

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2
Q

What are the changes that enable a species to cope with a specific niche called?

A

Adaptations.

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3
Q

What is the niche?

A

The role within an ecosystem

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4
Q

Give examples of adaptations.

A

eg Cactus storing water; squirrel can turn paws round; camel’s hump

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5
Q

What is the word for the environment in which a species lives?

A

Habitat

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6
Q

What do animals compete for?

A

Food, mate, living space/territory

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7
Q

What do plants compete for?

A

Light, nutrients, water, space

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8
Q

How would you show the feeding relationships of organisms?

A

Food web

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9
Q

What is the name for the way species rely on each other?

A

Interdependence

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10
Q

What happens if you change something for one species in a food web?

A

All the species are likely to be affected

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11
Q

What happens if a species cannot adapt quickly enough to a change in the environment?

A

Extinction

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12
Q

What happens to a species if the human activity removes the habitat?

A

Extinction is likely - eg Siberian tiger, Orangutan, mountain gorilla

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13
Q

What happens if a new species is introduced into an area?

A

Extinction is possible if the species is a competitor, predator, or causes disease. (eg cane toad in Australia)

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14
Q

What happens to other species in the food web if one species is extinct?

A

They may face extinction.

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15
Q

What is the source of energy for almost all species on earth?

A

The sun

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16
Q

What proportion of the energy of the sunlight do plants use?

A

A small amount (under 10%)

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17
Q

How do plants store the energy of the sun?

A

As chemical energy

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18
Q

How do organisms that can’t photosynthesise get their energy?

A

Mostly by eating green plants.

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19
Q

What does almost every food chain begin with?

A

A green plant

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20
Q

What proportion of the food eaten remains in the organism?

A

A small amount

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21
Q

Why is energy lost at each level of the food chain?

A

Some parts of the organism can’t be eaten/digested; respiration; waste products still contain energy

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22
Q

Why is the length of food chains limited?

A

Energy is lost at each stage

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23
Q

What is percentage efficiency of energy transfer

A

energy in tissue/energy in food eaten x 100

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24
Q

What happens to the energy contained in an organism after the organism dies?

A

It is transferred to the decomposers (fungi/bacteria). Also used by scavengers and predators.

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25
Q

What is partly decayed material called?

A

Detritus

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26
Q

What feeds on detritus?

A

Detritivores, eg earthworms, woodlice

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27
Q

What is the key element of the chemicals that make up living things

A

Carbon

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28
Q

What is the name for the process whereby carbon is reused on earth?

A

Carbon cycle

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29
Q

How does carbon enter the carbon cycle?

A

As carbon dioxide from the air

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30
Q

What do plants do to the carbon to make it accessible to living things?

A

Carbon is fixed via the process of carbon dioxide

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31
Q

How does carbon return to the air?

A

respiration; decomposition; combustion

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32
Q

How is nitrogen recycled?

A

Via the nitrogen cycle

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33
Q

How do plants take in nitrogen?

A

Nitrogen compounds in the soil are absorbed through the roots

34
Q

What are the nitrates made into by the plant?

A

Protein (via amino acids)

35
Q

What happens to the proteins in plants?

A

It passes along the food chain

36
Q

How do nitrates return to the soil?

A

Animals excrete waste, and are decomposed

37
Q

How does nitrogen enter the nitrogen cycle?

A

Nitrogen in the air split by lightening,combines with oxygen to form nitrates, washed into the soil by rain; nitrogen fixing bacteria, found in soil and in roots of some plants (beans, peas, clover)

38
Q

How does nitrogen leave the nitrogen cycle?

A

Denitrifying bacteria in the soil convert nitrates to nitrogen gas

39
Q

How can you measure environmental change?

A

Non-living indicators, eg CO2 levels ; living indicators eg phytoplankton

40
Q

What information can living indicators give us?

A

Precise measurement of pollution/climate change.

41
Q

What is the name given to measuring environmental change using living indicators?

A

Biotic scale

42
Q

Name an organism used for measuring pollution

A

The mayfly as mayfly larvae need high levels of oxygen in the water they are sensitive to pollution

43
Q

Why would you use non-living indicators?

A

They can give trends over a period of time.

44
Q

Where could you find historical levels of CO2?

A

Trapped in bubbles in ice

45
Q

When did life on earth begin?

A

3500 million years ago

46
Q

What was the first life form like

A

Very simple

47
Q

What is the process of change in living things called?

A

Evolution

48
Q

What is the best explanation we have for the change in living things?

A

The theory of evolution

49
Q

How can you date a fossil?

A

By the rock it is found in, also other similar fossils.

50
Q

How can you date a rock?

A

By the fossils found in it, rock layers

51
Q

What is the name for a change in the genetic information in the cell?

A

Mutation

52
Q

When are mutations most likely to occur?

A

When the DNA is being copied prior to cell division (transcription errors). Vast majority are corrected!

53
Q

What happens to an organism with a detrimental mutation?

A

It is less likely to have offspring

54
Q

What happens if the organism has an advantageous mutation?

A

It is more likely to have offspring

55
Q

What happens over time to the gene pool of an organism?

A

The alleles present will change

56
Q

What evidence is there to support the theory of evolution?

A

Fossil record; observation of living species; selective breeding of domestic animals; similarities between species

57
Q

What is natural selection?

A

The theory that the fittest organism is the most likely to pass on the genes that it has.

58
Q

How can a new breed of cat be produced?

A

Selective breeding of individuals who are closest to having the wanted features… eg a very long nose and blunt claws, with a mane, over many generations.

59
Q

Name a process of natural selection that is happening in our lifetime

A

Bacterial resistance is spreading in the gene pool of the bacteria. Eventually that allele will become the common one.

60
Q

How are organisms classified?

A

By putting similar organisms into groups

61
Q

How were similarities determined for the classification of animals?

A

Looking at them, eg teeth, body structure, etc

62
Q

How are similar organisms chosen now?

A

DNA testing shows which animals are closely related.

63
Q

How can DNA tell you which animals are related?

A

Their base sequences will be similar

64
Q

Who proposed the theory of evolution?

A

Darwin and Wallace

65
Q

What gave Darwin the idea of evolution?

A

Observing species on Galapagos. They are volcanic islands, so a few animals came from the mainland.

66
Q

What was Lamarck’s theory?

A

Lamarck suggested that animals acquired characteristics that were passed on to offspring

67
Q

What evidence was found for Lamarck’s theory?

A

None. However, some evidence now being found that whether genes are switched on or off can change in the life of an animal and can be passed on.

68
Q

What is biodiversity?

A

The variety of life on earth

69
Q

What is another name for the variation within a species?

A

Genetic diversity

70
Q

What is a kingdom?

A

A large group with many organisms with few characteristics in common

71
Q

What is the species?

A

The lowest level of classification.

72
Q

What is sustainability?

A

Meeting today’s needs without stopping future generations from meeting theirs.

73
Q

What do we need to do to achieve sustainability?

A

limit our impact on wildlife, habitats and the environment; actively support populations and ecosystems.

74
Q

How is biodiversity related to sustainability?

A

Biodiversity is essential to achieve sustainability, as removable of a single species can have such a devastating impact on the rest of the ecosystem

75
Q

How do our farms maximise crop yield?

A

They use a system called intensive monoculture crop production; fertilisers and pesticides, massive fields, no hedges, just one species

76
Q

Is intensive monoculture crop production sustainable?

A

Probably not; for instance, the over-use of pesticides is killing the bees that mankind relies on to fertilise our crops.

77
Q

How can we increase sustainability in product manufacture?

A

Use little energy and packaging; limiting transport and using local products; creating as little pollution as possible

78
Q

How is the environmental impact of a product tracked?

A

Life cycle assessment

79
Q

What are the stages of the life cycle assessment?

A

raw materials; manufacture; transport; use; disposal

80
Q

What can packaging be to be more sustainable?

A

Biodegradable

81
Q

Why is it better to use no packaging at all?

A

Even biodegradable packaging takes space in landfill and takes a long time to degrade. It can also produce methane.

Biology 21st century (12 decks)

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