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)?

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 has purple flowers?

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 a carrier daughter.

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

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

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

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

In a population of 10000 in Hardy–Weinberg equilibrium, 4% show a recessive trait. How many individuals N are expected to be homozygous dominant?