Genetics worksheet with answers

In pea plants, purple flowers (A) are dominant over white (a). A plant with genotype Aa is crossed with a plant with genotype aa. What is the probability P that an offspring is heterozygous (Aa)?

Two Bb parents are crossed. B gives black fur and is dominant over b, which gives white fur. Click the cell for an offspring that has black fur and is homozygous.

1. 1B × B
2. 2B × b
3. 3b × B
4. 4b × b

Tall (A) is dominant over short (a), and round seeds (B) over wrinkled (b). The genes are on different chromosomes. For the cross AaBb × AaBb, what is the probability P that an offspring is tall, wrinkled seeds?

red-green colour blindness is X-linked recessive (allele b). A carrier mother, X^BX^b, has children with an unaffected father, X^BY. The mother's gametes run down the side. Click the cell for an affected son.

1. 1X^B × Y
2. 2X^B × X^B
3. 3X^b × Y
4. 4X^b × X^B

Two AaBb parents are crossed. Gene A gives black fur (dominant) or white fur; gene B gives purple flowers (dominant) or white flowers. Click the one cell for an offspring that is shows both white fur and white flowers.

1. 1Ab × aB
2. 2Ab × ab
3. 3Ab × AB
4. 4Ab × Ab
5. 5ab × aB
6. 6ab × ab
7. 7ab × AB
8. 8ab × Ab
9. 9aB × aB
10. 10aB × ab
11. 11aB × AB
12. 12aB × Ab
13. 13AB × aB
14. 14AB × ab
15. 15AB × AB
16. 16AB × Ab

A recessive condition affects 16% of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?