Free Selection questions for IGCSE Biology (0610), part of Inheritance & variation. Each question has the answer and the marking points an examiner would look for.
C bacteria become used to the antibiotic → they pass on the resistance they acquired → resistance becomes more common
D mutation gives resistance in a few bacteria → antibiotic kills non-resistant bacteria → resistant bacteria survive and reproduce → resistance allele becomes more common
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Answer: D
Question 2Multiple choice · 1 mark
What is evolution?
A growth of an organism
B change in adaptive features of a population over time by natural selection
C learning new behaviour
D change in an organism during its life
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Answer: B
Question 3Multiple choice · 1 mark
Which statement describes natural selection?
A A mechanism that reverses a change to return a factor to its set point
B The greater chance of passing on genes by the best adapted organisms
C A cell with a long extension that increases surface area for water and ion uptake
D Choosing individuals with desirable features to breed together
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Answer: B
Question 4Structured · 6 marksA* challenge
Peppered moths in industrial areas became darker over time.
(a)
Explain how natural selection caused this change.
[4]
(b)
Suggest how the proportion of dark moths would change after air pollution was reduced, and explain why.
[2]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
dark variants camouflaged on sooty trees, survive, reproduce
variation: some moths were dark B1 on soot-covered trees dark moths were camouflaged B1 birds ate more light moths B1 dark moths survived to reproduce and passed on the allele B1
4
(b)
dark moths decrease
proportion of dark moths decreases / light moths increase B1 bark becomes lighter so light moths are camouflaged and dark moths are eaten more B1
2
Question 5Structured · 4 marks
Farmers use selective breeding to improve their crops.
(a)
Describe how a farmer could breed wheat with a higher yield.
[3]
(b)
Give one disadvantage of selective breeding.
[1]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
select best, cross, repeat many generations
select plants with the highest yield B1 cross them B1 repeat over many generations B1
3
(b)
reduced variation
reduces genetic variation, making crops vulnerable to disease B1
1
Question 6Structured · 13 marks
This question is about variation and selection.
(a)
Distinguish between continuous and discontinuous variation, giving an example of each.
[4]
(b)
State the type of variation usually caused by genes alone.
[1]
(c)
State two causes of genetic variation.
[2]
(d)
Peppered moths can be pale or dark. In industrial areas with soot-blackened trees, the dark form became more common. Explain this using natural selection.
[4]
(e)
Explain how selective breeding differs from natural selection.
[2]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
continuous: range of values, e.g. height; discontinuous: distinct categories, e.g. blood group
continuous variation has a range of values with no distinct categories B1 e.g. height / mass B1 discontinuous variation has distinct categories B1 e.g. blood group / tongue rolling B1
4
(b)
discontinuous
discontinuous B1
1
(c)
mutation; meiosis; random fertilisation
Any 2 of: mutation; meiosis (independent assortment); random fertilisation B2
2
(d)
variation; dark moths camouflaged, fewer eaten by birds; survive and reproduce; pass on allele
there is variation in colour in the population B1 dark moths are camouflaged on dark trees so fewer are eaten by predators (birds) B1 dark moths survive and reproduce B1 the allele for dark colour is passed on and becomes more frequent B1
4
(e)
humans choose which individuals breed; for desired features, not survival
humans choose individuals with desirable features to breed B1 rather than the environment selecting those best adapted to survive B1
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Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in