Genetics worksheet with answers

Two Tt parents are crossed. T gives purple flowers and is dominant over t, which gives white flowers. Click the cell for an offspring that has purple flowers and is homozygous.

1. 1t × T
2. 2t × t
3. 3T × T
4. 4T × t

Two Tt parents are crossed. T gives purple flowers and is dominant over t, which gives white flowers. Click the cell of the Punnett square for an offspring with white flowers.

1. 1t × t
2. 2t × T
3. 3T × t
4. 4T × T

haemophilia is X-linked recessive (allele h). A carrier mother, X^HX^h, has children with an unaffected father, X^HY. The mother's gametes run down the side. Click the cell for a carrier daughter.

1. 1X^h × X^H
2. 2X^h × Y
3. 3X^H × X^H
4. 4X^H × Y

red-green colour blindness is X-linked recessive (allele b). A carrier mother, X^BX^b, has children with an affected father, X^bY. The mother's gametes run down the side. Click the cell for an unaffected 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 purple flowers (dominant) or white flowers; gene B gives round seeds (dominant) or wrinkled seeds. Click the one cell for an offspring that is shows white flowers and is homozygous for round seeds.

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 2000 in Hardy–Weinberg equilibrium, 1% show a recessive trait. How many individuals N are expected to be homozygous dominant?