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
♂ Bb♀ BbbBbB

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

Bb × Bb
  1. 1b × b
  2. 2b × B
  3. 3B × b
  4. 4B × B
2.Easy
♂ Rr♀ RrrRRr

Two Rr parents are crossed. R gives round seeds and is dominant over r, which gives wrinkled seeds. Click the cell of the Punnett square for an offspring with wrinkled seeds.

Rr × Rr
  1. 1R × r
  2. 2R × R
  3. 3r × r
  4. 4r × R
3.Medium
♂♀YXd​Xd​XD​

Duchenne muscular dystrophy is X-linked recessive (allele d). A carrier mother, XDXd, has children with an affected father, XdY. The mother's gametes run down the side. Click the cell for an affected son.

♀ XDXd♂ XdY
  1. 1Xd × Y
  2. 2Xd × Xd
  3. 3XD × Y
  4. 4XD × Xd
4.Medium
♂♀XB​YXb​XB​

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

♀ XBXb♂ XBY
  1. 1Xb × XB
  2. 2Xb × Y
  3. 3XB × XB
  4. 4XB × Y
5.Hard
♂ AaBb♀ AaBbabAbaBABabaBAbAB

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

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 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 shows white 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

Answer key

  1. 1. B × B
  2. 2. r × r
  3. 3. Xd × Y
  4. 4. XB × Y
  5. 5. aB × aB
  6. 6. Ab × Ab

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