Genetics worksheet with answers

Free printable Genetics worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
Aa ♀Aa ♂AaAa????

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?

Aa × Aa
P =
2.Easy
♂ Aa♀ AaaAAa

Two Aa parents are crossed. A gives yellow seeds and is dominant over a, which gives green seeds. Click the cell of the Punnett square for an offspring with green seeds.

Aa × Aa
  1. 1A × a
  2. 2A × A
  3. 3a × a
  4. 4a × A
3.Medium
♂♀Xb​YXB​Xb​

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

♀ XBXb♂ XbY
  1. 1XB × Xb
  2. 2XB × Y
  3. 3Xb × Xb
  4. 4Xb × Y
4.Medium
♂♀YXb​XB​Xb​

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

♀ XBXb♂ XbY
  1. 1XB × Y
  2. 2XB × Xb
  3. 3Xb × Y
  4. 4Xb × Xb
5.Hard
♂ AaBb♀ AaBbABAbaBabABaBAbab

Two AaBb parents are crossed. Gene A gives yellow seeds (dominant) or green seeds; gene B gives purple flowers (dominant) or white flowers. Click the one cell for an offspring that is homozygous for yellow seeds and for purple flowers.

AaBb × AaBb
  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
6.Hard
♂ AaBb♀ AaBbaBAbABababAbABaB

Two AaBb parents are crossed. Gene A gives round seeds (dominant) or wrinkled seeds; gene B gives tall plants (dominant) or short plants. Click the one cell for an offspring that is shows wrinkled seeds and is homozygous for tall plants.

AaBb × AaBb
  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

Answer key

  1. 1. P = 0.75
  2. 2. a × a
  3. 3. Xb × Y
  4. 4. Xb × Xb
  5. 5. AB × AB
  6. 6. aB × aB

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