Q1.
Darwin’s theory of natural selection states that all living things have evolved from simple life forms.
(a)     Use the correct answer from the box to complete the sentence.
 
three billion                        three million                        three thousand	
Darwin’s theory states that life began on Earth _____________________
years ago.
(1)
(b)     Life evolved due to changes in genes. Changes in genes cause variation.
Complete the sentences.
Changes in genes are called ______________________________ .
Individuals with characteristics most suited to the environment are more likely 
to survive and _______________________ .
(2)
(Total 3 marks)
Q2.
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?
______________________________________________________________
______________________________________________________________
(1)
(iii)     Give two reasons, other than collision with an asteroid, why groups of animals may become extinct.
1. ____________________________________________________________
______________________________________________________________
2. ____________________________________________________________
______________________________________________________________
(2)
(b)     The graph shows how the rate of extinction of groups of animals has varied over the past 300 million 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).
(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)
Q3.
In the 1800s, Charles Darwin visited the Galapagos Islands. On the islands he found many different species of bird called finches. Darwin thought that all the different finch species had evolved from one species of finch that had reached the islands many years before.
(a)     Complete the following sentence.
Darwin suggested the theory of evolution by natural
___________________________________________________________________
(1)
(b)     The pie chart shows information about ten species of finch, A − J.
 
(i)      How many of the species of finch eat insects?
Draw a ring around the correct answer.
 
4	5	6	
(1)
(ii)     Describe finch species G.
Use only information from the pie chart.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(2)
(c)     When Darwin returned to the UK very few people believed his theory of evolution.
A different scientist suggested that the changes that occur in an organism during its lifetime can be inherited by its offspring.
What was the name of this scientist?
Tick () one box.
 
Lamarck		
Mendel		
Semmelweis		
(1)
(Total 5 marks)
Q4.
(a)     Complete the sentences about evolution.
Draw a ring around the correct answer to complete each sentence.
 
 	 	artificial	 	
(i)	Darwin suggested the theory of evolution by	natural	selection.	
 	 	asexual	 	
(1)
(ii)     Darwin’s theory of evolution says that all species of living things have
 
 	artificial	 	
evolved from	complex	life forms.	
 	simple	 	
(1)
 	 	three billion	 	
(iii)	Most scientists believe that life first developed about	three million	years ago.	
 	 	three thousand	 	
(1)
(b)     Darwin’s theory of evolution was only slowly accepted by other people.
Give two reasons why.
1 _________________________________________________________________
___________________________________________________________________
2 _________________________________________________________________
___________________________________________________________________
(2)
(c)     Diagram 1 shows one model of the relationship between some animals.
Diagram 1
 
(i)       Complete the sentence.
The model shown in Diagram 1 is an evolutionary _____________________ .
(1)
(ii)     Which two of the animals in Diagram 1 are most closely related?
_____________________________ and _____________________________
(1)
(iii)    Diagram 2 shows a more recent model of the relationship between the animals.
Diagram 2
 
Suggest one reason why scientists have changed the model of the relationships between the animals shown in the diagram.
Draw a ring around the correct answer.
 
more powerful
computers	new evidence
from fossils	new species
discovered	
(1)
(Total 8 marks)
Q5.
The bean aphid is a type of black-fly which lives on broad bean plants in summer.
In the autumn, males and females mate and produce eggs.
 
(a)     Name the type of reproduction which produces the eggs. 
___________________________________________________________________
(1)
(b)     In spring these eggs hatch. The young aphids are all female.
Explain why they are all similar but not identical to each other.
___________________________________________________________________
(1)
(c)     These females are then able to produce offspring without needing any males.
(i)      Name the type of reproduction where females do not need males to produce offspring.
______________________________________________________________
(1)
(ii)     How will the offspring from one of these females: 
A  compare with each other
______________________________________________________________
B  compare with the offspring from other females?
______________________________________________________________
(2)
(d)     Some scientists investigated mutations in these aphids. They exposed the aphids to X-rays.
They plotted their results.
 
(i)      What was the connection between the dose of X-rays and the percentage of mutations?
______________________________________________________________
(1)
(ii)     Name one other possible cause of mutations.
______________________________________________________________
(1)
(Total 7 marks)
Q6.
Charles Darwin proposed the theory of natural selection.
Many people at the time did not accept his theory.
(a)     There was a different theory at the same time as Darwin’s theory.
The different theory said that changes in an organism during its life could be inherited.
Who proposed this theory?
___________________________________________________________________
(1)
(b)     Studying fossils helps scientists understand how living things have evolved.
The diagram below shows a fossilised snake.
 
© Peter Menzel/Science Photo Library
Explain how the fossil in the diagram above may have formed.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(3)
(c)     There are many types of rat snake in the world.
The table below shows two types of rat snake.

© Kazzpix/iStock/Thinkstock 	
© Talkir/iStock/Thinkstock 	
Type of snake	Japanese rat snake	Texas rat snake	
Colour of snake	Green	Pale brown	
Type of environment	Grass	Dry and dusty	
The different types of rat snake have evolved from similar ancestors.
The rat snakes have evolved to to suit their environments.
Explain how the Japanese rat snake evolved to be different from the Texas rat snake.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(4)
(d)     Many species of snake have become extinct.
Give one reason why a species might become extinct.
___________________________________________________________________
___________________________________________________________________
(1)
(Total 9 marks)

Mark schemes
Q1.
(a)    three billion
1
(b)    mutation(s)
1
breed / reproduce
in this order only
allow pass on their genes
1
[3]
Q2.
(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
or
cannot perform experiment to test
1
[9]
Q3.
(a)      selection
1
(b)     (i)      4
1
(ii)     ground finch / lives on the ground
1
(only) eats seeds
allow eg eats seeds on / from the ground for 2 marks
1
(c)     Lamarck
1
[5]
Q4.
(a)     (i)      natural
1
(ii)     simple
1
(iii)    three billion
1
(b)     any two from:
•        reference to religion
•        insufficient evidence / couldn’t prove it / no proof
ignore no evidence
•        mechanism of inheritance / variation not known
allow genes / DNA not known about
•        reference to other theories
•        reference to Darwin’s status
2
(c)     (i)      tree
1
(ii)     hippopotamus and pig
both required, either order
allow hippo
1
(iii)    new evidence from fossils
1
[8]
Q5.
(a)     sexual / sex
for 1 mark
1
(b)     idea that
sexual reproduction brings about a mixture of genes 
or similar / different genes / parents / gametes / DNA / 
characteristics / chromosomes (not features)
for 1 mark
1
(c)     (i)      asexual / cloning  (allow vegetative)
for 1 mark
1
(ii)     (A)    idea that (they are exactly the same). Do not allow 
          similar or just one named feature.
for 1 mark
2
(B)     different (allow similar but do not allow same).
Allow any one named difference
for 1 mark
(d)     (i)      greater the X-ray dose, greater the % of mutations
or % of mutations increases steadily / in proportion to X-ray dose
for 1 mark
1
(ii)     ionising radiations / ultra-violet light / alpha particles / beta particles 
/ gamma rays / radio activity / chemicals / drugs / smoking / natural 
in meiosis / spontaneous / cell replication / toxic waste / pollution
1
         Accept radioactivity but not radiations alone.
for 1 mark
[7]
Q6.
(a)     (Jean Baptiste) Lamarck
allow phonetic spelling
1
(b)     (snake is) covered in sediment / mud
or
sinks into the mud
1
(then) the soft parts decay / are eaten
or
bones / hard parts do not decay
1
(so) minerals enter bones
or
bones are replaced by minerals
1
(c)     Level 3 (3–4 marks):
A detailed and coherent explanation is provided. Logical links between clearly identified, relevant points explain how the rat snake evolved through the process of natural
selection.
Level 2 (1–2 marks):
Simple statements made, but not precisely. The logic is unclear.
0 marks:
No relevant content.
Indicative content
statements:
•        there are lots of different colours of snakes
•        some shades of green are closer to the colour of the environment (in Japan) than others
•        survivors (in each generation) will breed and produce offspring
explanations:
•        different colours are controlled by different genes / alleles / are caused by mutations
•        being green means they are best suited to grassy / green environments
•        being green means they are camouflaged
•        those that are camouflaged best will be able to catch more food
•        those that are camouflaged best will be able to avoid being eaten
•        survivors’ offspring will inherit the genes / alleles / mutation for the shade of green colouration
additional examiner guidance:
•        allow converse points relating to the Texas rat snake if they clearly identify the
reasons why this snake was at an evolutionary disadvantage, ie more likely to be caught and eaten by a predator
•        a good level 2 answer will clearly link survival and breeding to the passing on of the advantageous genes / alleles / mutations and link the idea of colour (AO2) to a
correct explanation of its significance for survival
4
(d)     any one from:
•        changes to the environment
•        new predators
•        new diseases
•        new (more successful) competitors
•        catastrophic event / described event
1
[9]