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The formation of new species can occur as a result of evolution by natural selection.
Which of the following are required for natural selection to occur within a population?
[1 mark]
A
Individuals deciding to change to become better adapted to their environment
B
Random mutations
C
A stable environment
D
Introduction of a new predator
Your answer
Which scientist(s) formulated a theory of evolution by natural selection? [1 mark]
A
Darwin alone
B
Lamarck
C
Mendel
D
Darwin and Wallace
Your answer
Which of the following does not occur as part of evolution?
A
A change in inherited characteristics of a population over time.
B
The inheritance of acquired characteristics.
C
The process of natural selection.
D
The formation of a new species.
Your answer
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What is the genome? [1 mark]
A
The dominant genes which are expressed.
B
The entire genetic material of an organism.
C
The genes in an organism.
D
The length of DNA which codes for the making of a protein.
Your answer
Some bacteria have evolved to become resistant to antibiotics.
Which statement is true about the evolution of these bacteria?
A
Antibiotics killed the resistant bacteria.
B
Bacteria reproduce slowly allowing the resistance to have affect.
C
D
Mutations in some bacteria were an advantage.
Mutations occurred within the nucleus of the bacteria.
[1]
Your answer
Q1. Over millions of years:
•
new groups of organisms have evolved
•
other groups of organisms have become extinct.
(a) If an asteroid collided with the Earth, large amounts of dust and water vapour would be thrown up into
the air. This would mean less light and heat would reach the Earth’s surface from the Sun.
(i)
A reduced amount of light and heat could have caused the extinction of plants.
Suggest how.
_____________________________________________________________________________________
(1)
(ii)
How could the extinction of plants have caused the extinction of some animals?
_____________________________________________________________________________________
(iii)
Give two reasons, other than collision with an asteroid, why groups of animals may become extinct.
1.
____________________________________________________________________________________
2.
___________________________________________________________________________________
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(2)
(b)
million
The graph shows how the rate of extinction of groups of animals has varied over the past 300
years.
(i)
If more than 10 groups of animals become extinct in a 1 million year period, scientists call this a ‘mass
extinction’.
How many mass extinctions occurred over the past 300 million years?
____________________________________
(1)
(ii)
How do we know what types of animals lived hundreds of millions of years ago?
______________________________________________________________
______________________________________________________________
(1)
(c)
Use information from the graph to answer part (i) and (ii).
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(i)
How many years ago did the most recent mass extinction of animals occur?
Tick (✔) one box.
50 million years ago
65 million years ago
250 million years ago
(1)
(ii) What was the mean number of groups of animals becoming extinct per million years in the most
recent mass extinction?
________________ groups per million years
(1)
(iii) Why are scientists not sure how many groups of animals became extinct in the most recent mass
extinction?
______________________________________________________________
______________________________________________________________
(1)
(Total 9 marks)
Q2.
The Arabian oryx (Oryx leucoryx) is a mammal that was once extinct in the wild.
The image shows an Arabian oryx.
(a)
What is the genus of the Arabian oryx?
Tick one box.
leucoryx
Oryx
Oryx leucoryx
(1)
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(b)
Give two adaptations of the Arabian oryx to living in hot desert environments.
Use information from the image.
1. _________________________________________________________________
___________________________________________________________________
2. _________________________________________________________________
___________________________________________________________________
(2)
(c)
The Arabian oryx uses its long horns to fight for territory and mates.
Describe how the long horns could have evolved.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(3)
Arabian oryx from many different zoos were interbred so that they could be reintroduced to the wild.
(d)
What is the name of this method of increasing the population of endangered animals?
Tick one box.
Breeding programme
Genetic modification
Natural selection
Selective breeding
(1)
(e)
Explain why it was important to use Arabian oryx from many different zoos instead of one zoo.
___________________________________________________________________
___________________________________________________________________
(1)
(Total 8 marks)
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Q3.
Moose are animals that eat grass.
Figure 1 shows a moose.
Figure 1
© Wildnerdpix/iStock/Thinkstock
Figure 2 shows a food chain.
Figure 2
Grass
(a)
Moose
Wolves
Name the secondary consumer shown in Figure 2.
___________________________________________________________________
(1)
(b)
Figure 3 shows how the moose population and wolf population have changed in one area.
This is a predator-prey cycle.
Figure 3
In 2004 the
line on
Figure 3 for
wolves is
above the
line for moose.
How does Figure 3 show that there are more moose than wolves in 2004?
___________________________________________________________________
___________________________________________________________________
(1)
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(c)
Suggest why the moose population decreased between 2002 and 2004.
Use information from Figure 3.
___________________________________________________________________
___________________________________________________________________
(1)
(d)
The number of wolves is one biotic factor that could affect the size of the moose population.
Give two other biotic factors that could affect the size of the moose population.
1. _________________________________________________________________
___________________________________________________________________
2. _________________________________________________________________
___________________________________________________________________
(2)
(e)
Moose have distinct characteristics such as antlers.
Describe how moose may have evolved to have large antlers.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(5)
(Total 10 marks)
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Q4.The diagram below shows changes in the foot bones of four ancestors of modern horses over the past
50 million years.
(a) Describe two changes to the bones in the feet of horses that have taken place over the
past 50 million years.
___________________________________________________________________
___________________________________________________________________
(2)
(b)
Eohippus lived in swampy areas with soft mud.
Since this time the ground in the habitat has become drier and harder.
All of the horse ancestors were preyed upon by other animals.
(i)
Explain one advantage to Eohippus of the arrangement of bones in its feet.
______________________________________________________________
______________________________________________________________
(2)
(ii) The changes in the arrangement of the foot bones of horses support Darwin’s theory of evolution by
natural selection.
Explain how the arrangement of the foot bones of Eohippus could have evolved into the arrangement of the
foot bones of Equus.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(4)
(Total 8 marks)
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Mark schemes
Q1.
(a)
(i)
reduced photosynthesis
ignore growth
do not allow need light for respiration
1
(ii)
less food (for animals) or less oxygen (for animals)
allow loss of habitat
1
(iii)
any two from:
accept 2 physical factors or 2 biological factors or one of
each for full marks
examples of physical factors, eg
•
flooding
•
drought
•
ice age / temperature change
ignore pollution
•
volcanic activity
examples of biological factors, eg
•
(new) predators (allow hunters / poachers)
•
(new) disease / named pathogen
•
competition for food
•
competition for mates
•
cyclical nature of speciation
•
isolation
•
lack of habitat or habitat change
If no other answers given allow natural disaster / climate
change / weather change / catastrophic event /
environmental change for 1 mark
2
(b)
(i)
3
1
(ii)
fossils
ignore bones, remains, fossil fuels
1
(c)
(i)
65 million years ago
1
(ii)
17
allow ecf
1
(iii)
fossil record incomplete
or
some fossils destroyed
accept not enough evidence
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or
cannot perform experiment to test
1
[9]
Q2.
(a)
Oryx
1
(b)
any two from:
•
white / light colour (to reduce thermal gain)
•
short fur (to reduce thermal insulation)
•
little body fat
•
large hooves (to walk in sand)
•
camouflaged (against sand by light colour)
2
(c)
any three from:
•
variation in population
•
animals with longest horns more likely to survive / reproduce
•
passing on alleles for long horns
•
repeated over many generations
3
(d)
breeding programme
1
(e)
any one from:
•
to increase genetic diversity
do not accept to increase biodiversity
•
species may be unable to cope if environment changes
•
all susceptible to same diseases / inbreeding problems
allow otherwise all offspring would have similar genes or a
decreased gene pool
•
prevents inbreeding
1
[8]
Q3.
(a)
wolves
1
(b)
moose and wolves are on different scales
1
(c)
wolf population has increased so more moose are eaten
do not accept there are more wolves than moose
1
(d)
any two from:
•
•
(other) predators
allow correct examples
allow ‘humans hunting moose’
(new) pathogens
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•
allow diseases
competition
2
(e)
any four from:
•
•
•
•
•
variation (within species) of antler size
allow description relating to antlers
(caused by) different genes
as a result of sexual reproduction / process of meiosis / mutation
(phenotype) most suited to environment most likely to survive and breed
ignore natural selection unqualified
genes for large antlers (more likely to be) passed on to next generation
4
reference to mate selection
or
fighting
or
gaining territory
or
competition for mates
or
avoiding predation
1
[10]
Q4.
(a)
any two from:
•
larger / longer / thicker
allow examples eg fewer toes or bones fused
•
fewer (bones in total)
allow smaller surface area touching the ground
•
fewer bones touching the ground
2
(b)
(i)
large(r) surface / area in contact with the ground
or
low / less pressure on ground
1
(so) less likely to sink into mud / ground
or
(so) could run fast(er)
allow easy / easier to escape predators
1
(ii)
variation (in size / number / arrangement of bones)
allow mutation(s) (in size / number / arrangement of bones)
1
(and) those with large(r) / few(er) bones more suited to running or run faster
(on harder / drier ground)
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1
these survive and breed
allow ref to offspring for breed
1
(so) genes / DNA (for larger / fewer bones) passed on
allow alleles passed on
1
[8]
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