Biology Assignment

Inheritance Assignment

Directions: Complete the following assignment and then enter your answers on Titanium for credit.

I. A homozygous dominant brown mouse is crossed with a heterozygous brown mouse (tan is the recessive color).

1. What is the phenotypic ratio of this cross?

2. What is the probability of having a heterozygous offspring?

II. Two heterozygous red flowers (white flowers are recessive) are crossed.

3. What is the phenotypic ratio of this cross?

4. What is the genotypic ratio of this cross?

5. What is the probability of producing red flowers?

III. Co-dominance: A man who has type A blood has a child with a woman with type B blood, what are the possible genotypes for each parent?

6. Mother:

7. Father:

If the mother is heterozygous and the father is homozygous (your understanding of blood type will tell you if it is dominant or recessive), complete a Punnett square to show the possible blood types of their offspring and answer the question below.

8. What are the possible genotypes of the children?

What is the probability that their children will have:

9. Type A blood:

10. Type B blood:

11. Type O blood:

12. Type AB blood:

IV. Dihybrid cross (2 traits at once) – In rabbits, grey hair (H) is dominant to white hair (h) and black eyes (E) are dominant to red eyes (e).

13. What are the possible allele combinations for a rabbit with the genotype HhEe (Hint: independent assortment)

Complete the cross of the individual above (#13) with a white-haired, red-eyed rabbit.

14. What is the second rabbit’s genotype?

15. What are the chances of having a grey-haired, red-eyed rabbit?

16. What are the chances of having a white-haired, black-eyed rabbit?

V. Sex-linked trait: Color-blindness is a recessive sex-linked trait found on the X chromosomes. A man who is color-blind has a child with a woman who has normal vision (assume she is heterozygous).

17. What are the chances they will have a child who is color-blind?

18. What are the chances a son will be color-blind?

19. What are the chances a daughter will be color-blind?

20. Who are considered carriers of color-blindness?