Inheritance of Blood Types

Explore the genetics of human blood types (ABO system) with this worksheet, covering genotypes, phenotypes, and inheritance patterns.

Grade 9 Science BiologyGeneticsInheritance of Blood Types

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TextMultiple ChoiceFill in the Blanks2 Short AnswerImageTrue / False

Standards

HS-LS3-1HS-LS3-2

Topics

BiologyGeneticsBlood TypesABOInheritance

9 sections · Free to use · Printable

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Inheritance of Blood Types

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Read each question carefully and provide your best answer. Use the provided space for your responses.

Human blood types are determined by the presence or absence of specific antigens on the surface of red blood cells. The ABO blood group system is controlled by a single gene with three alleles: I^A, I^B, and i. I^A and I^B are codominant, while i is recessive.

1. Which of the following genotypes represents blood type O?

I^A I^A

I^A I^B

I^B I^B

2. A person with blood type AB has which of the following alleles?

Only I^A

Only I^B

I^A and I^B

I^A, I^B, and i

3. The universal donor blood type is .

4. The alleles I^A and I^B are , meaning both are expressed when present.

5. Explain what codominance means in the context of ABO blood types.

Diagram showing different types of blood cells

6. A person with blood type A can only have the genotype I^A I^A.

True

False

7. The Rh factor is also part of the ABO blood group system.

True

False

8. A mother has blood type A (genotype I^A i) and a father has blood type B (genotype I^B i). What are the possible blood types of their children and the probability of each?