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
♂ 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
2.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 is heterozygous (Aa)?

Aa × Aa
P =
3.Medium
AaBb ♀AaBb ♂ABAbaBabABAbaBab????????????????

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?

AaBb × AaBb
P =
4.Medium
AaBb ♀aaBb ♂ABAbaBabaBabaBab????????????????

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, round seeds?

AaBb × aaBb
P =
5.Hard
AAAa?Aa?aap (A)q (a)p (A)q (a)q² = 0.0025f = ?

A recessive condition affects 1 in 400 of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?

q² = 0.0025
f =
6.Hard
♂ AaBb♀ AaBbAbABabaBAbabABaB

Two AaBb parents are crossed. Gene A gives yellow seeds (dominant) or green seeds; gene B gives tall plants (dominant) or short plants. Click the one cell for an offspring that is shows both green seeds and short 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. r × r
  2. 2. P = 0.5
  3. 3. P = 0.1875
  4. 4. P = 0.375
  5. 5. f = 0.095
  6. 6. ab × ab

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