GCSE Biology (AQA) chapter 6: Inheritance, variation and evolution MCQs with answers

By Team Megalecture · Updated 4 Nov 2026

70 exam-style questions on Inheritance, variation and evolution, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.

70 questions · 5 topics · 10 per test

Test this chapter freeAll GCSE Biology (AQA) chapters

What chapter 6 covers

Ten Inheritance, variation and evolution questions with answers

Try each one, then open the answer. These ten stay the same; the test draws new ones every time.

1. Which is the correct sequence in evolution by natural selection?

  1. A
    individuals change during their lifetime to suit the environment, then pass those changes to their offspring
  2. B
    variation exists, and the best-adapted individuals survive, breed and pass on their alleles
  3. C
    all individuals are identical, so the environment decides which of them will survive
  4. D
    the environment causes mutations that are always helpful, so the whole population changes at once
Show answer

Answer: B. Natural selection acts on existing genetic variation: the best-adapted individuals survive, reproduce and pass on their alleles.

2. A mutation changes one base in the gene for an enzyme. Why might the enzyme stop working?

  1. A
    all the amino acids in the enzyme are replaced, so an entirely different enzyme is made
  2. B
    the mutation makes the enzyme move out of the cell, so the substrate cannot reach it
  3. C
    one amino acid may change, altering the shape of the active site
  4. D
    the mutation always stops the ribosome reading the rest of the gene
Show answer

Answer: C. A change in the base sequence may change an amino acid, so the protein folds differently; the substrate may no longer fit the active site.

3. Which is a reason why Darwin’s theory of natural selection was only gradually accepted?

  1. A
    it agreed with the belief that God made all living things and that species never change
  2. B
    Darwin delayed publishing until after he had died, so other scientists could not read it
  3. C
    it said that humans had evolved from chimpanzees, which scientists now know is wrong
  4. D
    the mechanism of inheritance and variation was not known at the time
Show answer

Answer: D. The theory challenged the belief that God made all living things, there was not enough evidence at the time, and the mechanism of inheritance was not understood.

4. Which is an example of genetic engineering?

  1. A
    bacterial cells modified to produce human insulin
  2. B
    crossing two tall pea plants and choosing the tallest offspring
  3. C
    growing new plants from cuttings taken from a healthy parent
  4. D
    splitting an embryo at an early stage and implanting the parts
Show answer

Answer: A. Genetic engineering transfers a gene from one organism to another; bacteria carrying the human insulin gene make insulin to treat diabetes.

5. What is an allele?

  1. A
    one of the 23 pairs of chromosomes found in a human body cell
  2. B
    a cell with half the normal number of chromosomes, such as a sperm cell
  3. C
    the complete set of genetic material found in an organism
  4. D
    one of the different versions of a gene
Show answer

Answer: D. Genes can exist in different versions called alleles, for example alleles for blue or brown eyes.

6. In guinea pigs, black fur (B) is dominant to white fur (b). A guinea pig has the genotype Bb. Which is its phenotype?

  1. A
    white fur, because it carries a recessive allele b
  2. B
    BB, because the dominant allele hides the recessive allele
  3. C
    half black fur and half white fur, because it has both alleles
  4. D
    black fur, because the dominant allele B is expressed even with one copy
Show answer

Answer: D. The phenotype is the characteristic that is expressed. Bb is the genotype; because B is dominant, the guinea pig has black fur.

7. A population of lizards is split by a new river. Which sequence best describes how a new species could form?

  1. A
    isolated groups face different selection pressures until they cannot interbreed
  2. B
    the lizards mutate to suit the river, and each group becomes unable to breed with the other
  3. C
    the two groups keep interbreeding across the river, so they gradually merge into a single species
  4. D
    each group chooses to change its features, and they stop recognising each other as mates
Show answer

Answer: A. Speciation needs isolation plus different selection pressures over many generations, until the populations can no longer interbreed to produce fertile offspring.

8. What do evolutionary trees show?

  1. A
    the order in which species were discovered and named by scientists over time
  2. B
    how species are related, based on living and fossil evidence
  3. C
    which organisms feed on which others in a food web within a habitat
  4. D
    the number of individuals of each species that are alive on Earth today
Show answer

Answer: B. Evolutionary trees use data from living and fossil organisms to show how closely related organisms are and their common ancestors.

9. A patient’s body has 1 000 000 bacteria. An antibiotic kills all but 10 resistant bacteria, which then divide every 20 minutes with none dying. How many resistant bacteria are there after 2 hours?

  1. A
    60
  2. B
    1200
  3. C
    640
  4. D
    1280
Show answer

Answer: C. 2 hours = 120 minutes = 6 divisions, so the number doubles 6 times: 10 × 26 = 10 × 64 = 640.

10. During protein synthesis, what brings the amino acids to the ribosome in the correct order?

  1. A
    the DNA itself, which leaves the nucleus and is read directly by the ribosome
  2. B
    carrier molecules, matching a template copied from the gene in the nucleus
  3. C
    hormones in the blood, which deliver each amino acid to the ribosome in turn
  4. D
    the cell membrane, which sorts the amino acids into the order that is needed
Show answer

Answer: B. A template of the gene is carried to the ribosome; carrier molecules bring specific amino acids to match the template, which are joined into a protein.

Start the chapter testAbout the GCSE Biology (AQA) test

Read the notes for this chapter

Ways to practise this chapter

Inheritance, variation and evolution: questions students ask

How many Inheritance, variation and evolution MCQs are there?

70, each with the answer and a short explanation, across 5 topics: 4.6.1.1–4.6.1.5 Reproduction, meiosis and DNA, 4.6.1.6–4.6.1.8 Genetic inheritance, inherited disorders and sex determination, 4.6.2 Variation, evolution and genetic technologies, 4.6.3 Development of understanding of genetics and evolution, 4.6.4 Classification of living organisms. Every chapter test draws ten of them, so you can take it many times.

Is the GCSE Biology (AQA) chapter 6 test free?

Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.

How is the chapter test marked?

The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.

Keep going

← Chapter 5: Homeostasis and responseChapter 7: Ecology →All chaptersStuck? Ask a question