Question 1 — IGCSE 0653 Mar 2023 Paper 12 Q40
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Correct answer: C
Cambridge IGCSE·Combined Sciences 0653·Biology
Inheritance
Key knowledge — Inheritance
Key facts & rules
- Chromosome: structure made of DNA; humans have 46 (23 pairs); gametes have 23 (haploid).
- Gene: section of DNA that codes for a protein/characteristic.
- Allele: a version of a gene. Dominant allele (capital letter) masks recessive (lower case).
- Genotype: genetic makeup (e.g. Tt). Phenotype: observable characteristics.
- Homozygous: both alleles the same (TT or tt). Heterozygous: different alleles (Tt).
- Monohybrid cross: Punnett square — 3:1 ratio (Aa × Aa) or 1:2:1 (genotype ratio).
- Sex determination: XX = female; XY = male. Father determines sex of offspring.
- Mutation: change in DNA sequence — can be caused by radiation or chemicals.
- Meiosis: produces 4 haploid gametes with genetic variation (crossing over + independent assortment).
IGCSE Biology — Inheritance
29 Cambridge IGCSE 0653 Combined Sciences past paper questions on inheritance, across Theory, Multiple Choice and Alternative to Practical.
About Inheritance on IGCSE 0653
Genes are sections of DNA that code for proteins. Alleles are different versions of a gene. Monohybrid crosses use Punnett squares to predict the probability of offspring having particular phenotypes.
What's covered:
- Chromosomes, genes and alleles
- Dominant and recessive alleles
- Genotype vs phenotype
- Monohybrid crosses and Punnett squares
- Mitosis and meiosis
- Sex determination in humans
- Mutations
Multiple choice
Inheritance — Core MCQ14 · Paper 1
Question 2 — IGCSE 0653 Mar 2024 Paper 12 Q40
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Correct answer: C
Question 3 — IGCSE 0653 Mar 2025 Paper 12 Q40
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Correct answer: C
Question 4 — IGCSE 0653 May/Jun 2023 Paper 11 Q40
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Correct answer: C
Question 5 — IGCSE 0653 May/Jun 2023 Paper 12 Q40
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Correct answer: B
Question 6 — IGCSE 0653 May/Jun 2023 Paper 13 Q40
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Correct answer: B
Question 7 — IGCSE 0653 May/Jun 2024 Paper 11 Q40
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Correct answer: A
Question 8 — IGCSE 0653 May/Jun 2024 Paper 12 Q40
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Correct answer: B
Question 9 — IGCSE 0653 May/Jun 2024 Paper 13 Q40
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Correct answer: D
Question 10 — IGCSE 0653 May/Jun 2025 Paper 11 Q40
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Correct answer: A
Question 11 — IGCSE 0653 May/Jun 2025 Paper 13 Q40
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Correct answer: A
Question 12 — IGCSE 0653 Oct/Nov 2023 Paper 11 Q40
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Correct answer: C
Question 13 — IGCSE 0653 Oct/Nov 2023 Paper 12 Q40
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Correct answer: D
Question 14 — IGCSE 0653 Oct/Nov 2023 Paper 13 Q40
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Correct answer: D
Inheritance — Extended MCQ15 · Paper 2
Question 1 — IGCSE 0653 Mar 2023 Paper 22 Q40
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Correct answer: C
Question 2 — IGCSE 0653 Mar 2024 Paper 22 Q40
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Correct answer: A
Question 3 — IGCSE 0653 Mar 2025 Paper 22 Q40
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Correct answer: D
Question 4 — IGCSE 0653 May/Jun 2023 Paper 21 Q40
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Correct answer: A
Question 5 — IGCSE 0653 May/Jun 2023 Paper 22 Q40
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Correct answer: B
Question 6 — IGCSE 0653 May/Jun 2023 Paper 23 Q40
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Correct answer: B
Question 7 — IGCSE 0653 May/Jun 2024 Paper 21 Q40
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Correct answer: B
Question 8 — IGCSE 0653 May/Jun 2024 Paper 22 Q40
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Correct answer: B
Question 9 — IGCSE 0653 May/Jun 2024 Paper 23 Q40
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Correct answer: B
Question 10 — IGCSE 0653 May/Jun 2025 Paper 21 Q40
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Correct answer: C
Question 11 — IGCSE 0653 May/Jun 2025 Paper 22 Q40
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Correct answer: B
Question 12 — IGCSE 0653 May/Jun 2025 Paper 23 Q40
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Correct answer: D
Question 13 — IGCSE 0653 Oct/Nov 2023 Paper 21 Q40
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Correct answer: B
Question 14 — IGCSE 0653 Oct/Nov 2023 Paper 22 Q40
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Correct answer: A
Question 15 — IGCSE 0653 Oct/Nov 2023 Paper 23 Q40
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Correct answer: B
All Inheritance questions in this collection
| Type | Level | Paper | Session | Q# | Marks | Answer / key |
|---|---|---|---|---|---|---|
| MCQ | Core | Paper 12 | Mar 2023 | Q40 | 1 mark | C |
| MCQ | Core | Paper 12 | Mar 2024 | Q40 | 1 mark | C |
| MCQ | Core | Paper 12 | Mar 2025 | Q40 | 1 mark | C |
| MCQ | Core | Paper 11 | May/Jun 2023 | Q40 | 1 mark | C |
| MCQ | Core | Paper 12 | May/Jun 2023 | Q40 | 1 mark | B |
| MCQ | Core | Paper 13 | May/Jun 2023 | Q40 | 1 mark | B |
| MCQ | Core | Paper 11 | May/Jun 2024 | Q40 | 1 mark | A |
| MCQ | Core | Paper 12 | May/Jun 2024 | Q40 | 1 mark | B |
| MCQ | Core | Paper 13 | May/Jun 2024 | Q40 | 1 mark | D |
| MCQ | Core | Paper 11 | May/Jun 2025 | Q40 | 1 mark | A |
| MCQ | Core | Paper 13 | May/Jun 2025 | Q40 | 1 mark | A |
| MCQ | Core | Paper 11 | Oct/Nov 2023 | Q40 | 1 mark | C |
| MCQ | Core | Paper 12 | Oct/Nov 2023 | Q40 | 1 mark | D |
| MCQ | Core | Paper 13 | Oct/Nov 2023 | Q40 | 1 mark | D |
| MCQ | Extended | Paper 22 | Mar 2023 | Q40 | 1 mark | C |
| MCQ | Extended | Paper 22 | Mar 2024 | Q40 | 1 mark | A |
| MCQ | Extended | Paper 22 | Mar 2025 | Q40 | 1 mark | D |
| MCQ | Extended | Paper 21 | May/Jun 2023 | Q40 | 1 mark | A |
| MCQ | Extended | Paper 22 | May/Jun 2023 | Q40 | 1 mark | B |
| MCQ | Extended | Paper 23 | May/Jun 2023 | Q40 | 1 mark | B |
| MCQ | Extended | Paper 21 | May/Jun 2024 | Q40 | 1 mark | B |
| MCQ | Extended | Paper 22 | May/Jun 2024 | Q40 | 1 mark | B |
| MCQ | Extended | Paper 23 | May/Jun 2024 | Q40 | 1 mark | B |
| MCQ | Extended | Paper 21 | May/Jun 2025 | Q40 | 1 mark | C |
| MCQ | Extended | Paper 22 | May/Jun 2025 | Q40 | 1 mark | B |
| MCQ | Extended | Paper 23 | May/Jun 2025 | Q40 | 1 mark | D |
| MCQ | Extended | Paper 21 | Oct/Nov 2023 | Q40 | 1 mark | B |
| MCQ | Extended | Paper 22 | Oct/Nov 2023 | Q40 | 1 mark | A |
| MCQ | Extended | Paper 23 | Oct/Nov 2023 | Q40 | 1 mark | B |