Practise 40 real questions on Inheritance, variation and evolution from 2021 to 2026. See the answer and explanation as soon as you answer.
Inheritance, variation and evolution is one of the 13 main topics in our O Level Biology (Cambridge (CAIE) 5090) question bank, and about 7% of its real questions come from it. Tayyari Karo has 40 real questions on this topic from 2021 to 2026, from Paper 1, Paper 2; 36 are multiple choice and marked instantly, and the rest are structured questions with a model answer. By difficulty: 33 medium, 6 easy, 1 hard.
Work through the questions below, then open the explanation for each one. Redo the ones you missed a few days later.
These are real past-paper questions. Think of your answer first, then open the explanation.
What is an example of continuous variation?
Answer: B. body mass
Body mass shows a range of values between extremes; the others fall into distinct categories.
Which statements refer to discontinuous variation (1 body mass 2 limited forms no intermediates 3 any value min to max 4 unaffected by environment 5 caused by genes only)?
Answer: C. 2, 4 and 5
Night-blindness is inherited. Couple 4 and 5 are expecting their second child (individual 7). What is the probability that individual 7 will be a male and also show night-blindness?
Answer: D. 0.125
A scientist takes four pairs of samples from a wild cherry tree. In which pair of samples could there be cells with different genotypes?
Answer: A. two seeds
A variety of snail has: StSt thick shells, StSn thin shells, SnSn do not survive. Two heterozygous snails are mated. What is the probability that a surviving snail of the next generation is a heterozygote?
Answer: D. 0.67
Which statements about natural selection are correct? natural selection can lead to better adapted species surviving / natural selection can lead to extinction of a species / natural selection can lead to gene mutations occurring
Answer: B. true / true / false
(a) Explain the role of the nucleus and cell division in the inheritance of characteristics from parents to offspring. [6] (b) Suggest how exposure to ionising radiation may affect inheritance of characteristics. [4]
(a) The nucleus contains chromosomes made of DNA; genes on the chromosomes carry instructions for characteristics; gametes are formed by meiosis and contain half the chromosome number; fertilisation joins male and female gametes so the offspring receives genes from both parents; mitosis divides cells for growth/repair, copying the genetic information. (b) Ionising radiation can cause mutations in DNA/gametes; these changes may be inherited by offspring; they can produce new alleles or harmful defects; increased mutation rate.
Best-effort; mark scheme not parsed.
| Session | Paper 1 | Paper 2 |
|---|---|---|
| May/June 2026 | 3 | – |
| May/June 2025 | 1 | 1 |
| Oct/Nov 2025 | 4 | – |
| May/June 2024 | 5 | – |
| Oct/Nov 2024 | 4 | – |
| May/June 2023 | 3 | – |
| Oct/Nov 2023 | 3 | 1 |
| May/June 2022 | 2 | – |
| Oct/Nov 2022 | 4 | 1 |
| May/June 2021 | 3 | – |
| Oct/Nov 2021 | 4 | 1 |
40 real O Level Biology (5090) questions on Inheritance, variation and evolution from 2021 to 2026, from Paper 1, Paper 2. Each one shows the year, session and paper it came from.
Yes. Every question shows the correct answer and a short explanation the moment you answer.
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