Evolution Flashcards

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1
Q

How long ago was the big bang?

A

13.7 billion years

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2
Q

How long ago was the sun formed?

A

5.6 billion years ago

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3
Q

How long ago was the Earth formed?

A

4.6 billion years ago

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4
Q

How long ago was the first life?

A

3.6 billion years ago

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5
Q

Can we know for sure how and when life on Earth began? Why?

A

no

no-one was there to observe it

we cannot do experiments to repeat the origin of life

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6
Q

What was Lamarck’s theory?

A

The inheritance of aquired characteristics

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7
Q

What does Lamarck’s theory say?

A

characteristics of individuals change during their own lifetime

the changed (aquired) characteristics are passed on to the next generation

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8
Q

Use the example of long necks for giraffes to explain Lamarck’s theory

A

giraffes used to have short necks, but they preffered to eat leaves from high trees

as they reached for high trees their necks became longer

the long neck characteristic was passed on to offspring

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9
Q

What are the pros of Lamarck’s theory?

A

changes in individuals can be aquired over time

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10
Q

What are the cons of Lamarck’s theory?

A

aquired characteristics are not passed on

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11
Q

What was Darwin’s theory?

A

Theory of evolution by natural selection

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12
Q

What was Darwin’s observations on finches?

A

there is a lot of variation between species

different islands have different food sources

different beaks suit different food sources

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13
Q

What were Darwin’s conclusions?

A

finches show variation in beak size and shape

finches with long, thin beaks are better adapted to catch insects living between rocks, compared to finches with wide, short breaks

finches with long, thin beaks are more likely to survive and breed while less well adapted finches may die before reproducing

the characteristics of the finches with long, thin beaks are passed on to the offspring

over time the number of finches with long, thin beaks increases, while the number of finches with short, wide beaks decreases

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14
Q

What is natural selection

A

mechanism for evolution

explains how some characteristics become more common

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15
Q

What does natural selection show about selection pressures?

A

selection pressures exist in environment (e.g. food source)

this leads to selection (survival) of those organisms that are best suited to this particular environment

these survive and pass on their genes (while others don’t)

characteristics of these organisms become more common

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16
Q

What are some examples of selection pressures?

A

predators

food

disease

climate

finding a mate

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17
Q

where does variation come from?

A

random mutations in genes

not forced by the environment

variation exists before selective pressures (but can be useful later)

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18
Q

Complete this beetle example diagram

A
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19
Q

what are peppered moths?

A

there are dark and light forms of the peppered moth

moths rest on tree bark during the day

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20
Q

before the industrial revolution what was the case with tree bark and peppered moths?

A

tree bark was covered with lichen (makes bark pale)

predomincance of light forms of moth in UK

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21
Q

after the industrial revolution what was the case with tree bark and peppered moths?

A

dark forms in polluted areas (light forms in rural areas)

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22
Q

Complete this table about peppered moths

A
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23
Q

Complete this table about antibiotic resistant bacteria

A
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24
Q

Complete this table about sickle cell anaemia

A
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25
Q

why is it better to be a carrier of sickle cell anaemia in regions with malaria than not to be?

A

if you are a carrier then you cannot have sickle cell anaemia

thus you are protected

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26
Q

what is the definition of Darwin’s Theory of Evolution?

A

all species of living things have evolved from simple life-forms which first developed more than three billion years ago through the process of natural selection

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27
Q

what is the variation, selection pressure and organisms selected for for rabbits with very long ears in the desert?

A

variation = different ear length

selection = hot temperature

organisms selected for = long ears - larger SA/V ratio, easier to lose heat

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28
Q

what is the variation, selection pressure and organisms selected for stick insects?

A

variation = different colours/shape of insect

selection pressure = predators

organisms selected for = good camouflage - harder for predator to find them

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29
Q

what is the variation, selection pressure and organisms selected for giraffes having long necks?

A

variation = different neck length

selection pressure = food - high up and mates

organisms selected for = long necks -able to reach food, attractive

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30
Q

what is the variation, selection pressure and organisms selected for cacti having spines instead of leaves?

A

variation = different sized spines/ leaves

selection pressure = heat (water loss), herbivores

organisms selected for = smaller SA and least water is lost, protection from predators

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31
Q

what is the variation, selection pressure and organisms selected for peacocks having brighlty coloured feathers?

A

variation = different feather colours

selection pressure = finding a mate (sexual selection)

organisms selected for = most brightly coloured feathers - most attractive

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32
Q

what is a fossil?

A

mineralised or otherwise preserved remians of organisms

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33
Q

what two categories of fossils are there?

A

body fossils

trace fossils

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34
Q

what is a body fossil?

A

fossilised remains of an organism

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35
Q

what are some examples (9) of body fossils?

A

bones

claws

teeth

eggs

embryos

skin

muscles

tendons

organs

36
Q

what is a trace fossil?

A

fossilised record of the activity of an organism

37
Q

what are some examples (6) of a trace fossil?

A

trackways (set of footprints)

toothmarks

gastroliths (stones swallowed and used for digestion to grind food)

coprolites (fossilised faeces)

burrows

nests

38
Q

what are the types (3) of fossils?

A

mold fossils

cast fossils

true form fossils

39
Q

what is a mold fossil?

A

fossilised impression (negative image)

40
Q

what is a cast fossil?

A

formed when mold fills in

41
Q

what is a true form fossil?

A

fossil of actual organism

42
Q

what are the types (6) of formation of fossils?

A

unaltered preservation

permineralisation = petrification

replacement

carbonisation = coalification

recrystallisation

authigenic preservation

43
Q

what is unaltered preservation?

A

insects or plant parts trapped in amber, a hardened form of tree sap

44
Q

what is permineralisation?

A

= petrification

rock-like minerals seep in slowly and replace the original organis tissue with silica, calcite or pyrite, forming rock-like fossil

45
Q

what is replacement?

A

an organism’s hard parts dissolve and are replaced by other minerals, like calcite, silica, pyrite or iron

46
Q

what is carbonisation?

A

= coalification

in which only the carbon remains in the specimen - other elements, like oxygen and nitrogen are removed

47
Q

what is recrystallisation?

A

hard parts either revert to more stable minerals or small crystals turn into larger ones

48
Q

what is authigenic preservation?

A

molds and casts of organisms that have been destroyed or dissolved

49
Q

what can fossils tell us (3)?

A

when animals presumbly lived

how much or how little species have changed over time

what sorts of organisms existed that are no longer around

50
Q

what can’t fossils tell us (2)?

A

what organisms looked like exactly

if organisms are really derived from one another

51
Q

what is extinction?

A

the permanent loss of all the members of a species from earth

52
Q

what is mass extinction?

A

loss of a number of species at the same time

53
Q

what are some examples (4) of mass extinction?

A

environmental change - climate change (e.g. the Ice Age), meteorites, vocanoes

new predators

new diseases

competition

54
Q

what is this type of formation of fossils is this?

insects or plant parts trapped in amber, a hardened form of tree sap

A

unaltered preservation

55
Q

what is this type of formation of fossils is this?

= petrification

rock-like minerals seep in slowly and replace the original organis tissue with silica, calcite or pyrite, forming rock-like fossil

A

permineralisation

56
Q

what is this type of formation of fossils is this?

an organism’s hard parts dissolve and are replaced by other minerals, like calcite, silica, pyrite or iron

A

replacement

57
Q

what is this type of formation of fossils is this?

= coalification

in which only the carbon remains in the specimen - other elements, like oxygen and nitrogen are removed

A

carbonisation

58
Q

what is this type of formation of fossils is this?

hard parts either revert to more stable minerals or small crystals turn into larger ones

A

recrystallisation

59
Q

what is this type of formation of fossils is this?

molds and casts of organisms that have been destroyed or dissolved

A

authigenic preservation

60
Q

Complete this gap fill:

One important piece of for how life has developed on eath is . The most common type are formed when parts of the or are replaced by as they decay over long periods of time. Some were formed when an organisms did not after it died. are rare.

A

One important piece of evidence for how life has developed on eath is fossils. The most common type are formed when parts of the plant or animals are replaced by minerals as they decay over long periods of time. Some fossils were formed when an organisms did not decay after it died. Ice fossils are rare.

61
Q

Complete this gap fill:

The theory of evolution states that all the which are alive today - and many more which are now extinct from simple life forms, which first developed more than three years ago. Darwin’s theory of evolution takes place through selection. Studying the similarities and differenced between species helps us to understand how they have evolved and how closely they are to each other. When a has a good effect it produced an which makes an better suited to its . This makes it more likely to and . The then gets passed on to the next . This is .

A

The theory of evolution states that all the species which are alive today - and many more which are now extinct evolved from simple life forms, which first developed more than three billion years ago. Darwin’s theory of evolution takes place through natural selection. Studying the similarities and differenced between species helps us to understand how they have evolved and how closely related they are to each other. When a mutation has a good effect it produced an adaptation which makes an organism better suited to its environment. This makes it more likely to survive and reproduce. The mutation then gets passed on to the next generation. This is natural selection.

62
Q

Complete this gap fill:

is the permanent loss of all the members of a from the . It may be caused by changes in the or , to new , new or possibly new

A

Extinction is the permanent loss of all the members of a species from the earth. It may be caused by changes in the environment or climate, to new predators, new disease or possibly new competitors

63
Q

what is selective breeding?

A

breeding only those individuals with desired characteristics (artificial insemination)

64
Q

what are some desired characteristics (8) for plants?

A

high yield

disease resistant

pesticide resistant

hardier (survive in harsh climates)

good nutrient balance in crops

high growth rate

flavour

looks (e.g. flower)

65
Q

what are some desired characteristics (7) for animals?

A

more meat, milk, eggs

more fur/better quality fur

more offspring

disease resistant

soeed (e.g. race horse)

looks (e.g. dogs)

character (e.g. dogs)

66
Q

How does selective breeding work in milk cows?

A

there is natural variation in milk cows

select high yield milk cow

mate with bull from high yield milk cow family (artificial insemination)

select high yield offspring and repeat process

67
Q

what is the selection pressure in natural selection vs artificial selection (selective breeding)?

A

natural selection = disease, climate, predators

artificial selection = human choice

68
Q

who survies the selection pressure in natural selection vs artificial selection (selective breeding)?

A

natural selection = only organisms with favourable traits survive and breed

artificial selection = only organisms with desired traits are chosen to breed

69
Q

what is the selection pressure of wheat?

A

high yield

high resistance

70
Q

what is a modern breeding technique?

A

cloning

71
Q

what is cloning?

A

any method that produces genetically identical offspring

72
Q

what two ways can you clone plants?

A

cutting

micropropagation

73
Q

how do you clone plants through cuttings?

A

take a small piece of plant and grow it in the right conditions

74
Q

how do you clone plants through micropropagation?

A

take a few cells/ or small parts from the plant (= explants)

put them into culture medium

let them grow into many new plants

75
Q

what way can you clone animals?

A

reproductive cloning

76
Q

how do you clone animals through reproductive cloning?

A

transfer a nucleus from a somatic cell of donar A to an empty egg cell from B to form a diploid zygote with A’s DNA

the developing embryo is implanted into the uterus of a foster mother (C) to develop and give rise to a clone of A

77
Q

what is the natural variation (due to chance mutation) in sickle cell anaemia in malaria-free regions (e.g. Europe) vs regions with malaria (e.g. Africa)

A

malaria-free regions = sickle cell haemoglobin + normal haemoglobin

malaria = sickle cell haemoglobin + normal haemoglobin

78
Q

what is the selection pressure in sickle cell anaemia in malaria-free regions (e.g. Europe) vs regions with malaria (e.g. Africa)

A

malaria-free regions = oxygen transport

malaria = oxygen transport + malaria

79
Q

which type has the selective advantage in sickle cell anaemia in malarie-free regions (e.g. Europe) vs regions with malaria (e.g. Africa)

A

malarie-free = HnHn

malaria = HnHs

(H = haemoglobin, N = normal, S = sickle)

80
Q

which type is selected for in sickle cell anaemia in malarie-free regions (e.g. Europe) vs regions with malaria (e.g. Africa)

A

malaria-free = HnHn

malaria = HnHs

(H = haemoglobin, N = normal, S = sickle)

81
Q

which type is selected against in sickle cell anaemia in malarie-free regions (e.g. Europe) vs regions with malaria (e.g. Africa)

A

malaria-free = HsHs, HnHs

malaria = HsHs, HnHn

82
Q

what is the result over generations in sickle cell anaemia in malarie-free regions (e.g. Europe) vs regions with malaria (e.g. Africa)

A

malaria-free = sickle cell anaemia-free

malaria = sickle cell anaemia still present

83
Q

Why do people in regions with malaria want one HnHs?

A

they will survive and cannot catch malaria

HsHs = dies of malaria

HnHn = can catch malaria and die

84
Q

Describe what is meant by a mutation and explain the effect a mutation could have in a population of organisms

A

mutation = change/damage/ mistake to genetic material

passed on

rare/random

alters characteristics (e.g. sickle cell)

increase/decrease of gene/allele/ numbers in population

natural selection/evolutio

must give examples of advantages/disadvantages and characteristics

85
Q

describe the process of selective breeding

A

humans/farmers select organisms

desired features/characteristics chosen

mate/reproduce/cross/artificial insemination

repeat/several generations/ select offspring

86
Q

give one example of two desired characteristics developed by selective breeding in a named crop plant

A

desired characteristic = high yield / short stem

crop plant = wheat

87
Q

give two ways in which natural selection differs from selective breeding

A
  1. the selection pressure of selective breeding is human choice whereas in natural selection it is factors such as disease or predators
  2. in artificial selecion, only organisms with desired traits are chosen to breed whereas in natural selection only organisms with favourable traits survive and breed