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3.3 Inheritance

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Question 3

The ABO blood groups in humans are controlled by one gene with three alleles, $I^A$ , $I^B\,$ and $I^O$ .

The alleles $I^A\,$ and $I^B\,$ are codominant. The allele $I^O\,$ is recessive.

State what is meant by the term multiple alleles.

[1]

Give the blood group of a person with the genotype $I^A I^O$ .

[1]

Give the two possible genotypes of a person with blood group B.

[2]

A person has the genotype $I^A I^B$ .

State the blood group of this person and explain your answer.

[2]

Give the genotype of a person with blood group O.

[1]

Markscheme

3.3 Inheritance Questions

GCSE
Biology
3.3 Inheritance

43 exam-style questions on Edexcel GCSE Biology 3.3 Inheritance, covering 3.3.1 Gregor Mendel and the basis of genetics, 3.3.2 Alleles and inherited characteristics, 3.3.3 Monohybrid inheritance, 3.3.4 Determination of sex at fertilisation, 3.3.5 Outcomes from monohybrid crosses, 3.3.6 Inheritance of ABO blood groups, 3.3.7 Inheritance of sex-linked disorders, and 3.3.8 Multiple genes and phenotypic features. Each one has a worked solution and a mark scheme showing where the marks go.

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