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.

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

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 white flowers?

Aa × Aa
P =
2.Easy
♂ Tt♀ TtTtTt

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

Tt × Tt
  1. 1T × T
  2. 2T × t
  3. 3t × T
  4. 4t × t
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 short, round 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 short, round seeds?

AaBb × Aabb
P =
5.Hard
AA?AaAaaap (A)q (a)p (A)q (a)q² = 0.0004N = 10000

In a population of 10000 in Hardy–Weinberg equilibrium, 1 in 2500 show a recessive trait. How many individuals N are expected to be homozygous dominant?

N = 10000q² = 0.0004
N =
6.Hard
♂ AaBb♀ AaBbabaBABAbAbaBABab

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

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 = 0.25
  2. 2. t × t
  3. 3. P = 0.25
  4. 4. P = 0.125
  5. 5. N = 9604
  6. 6. Ab × Ab

Full step-by-step solutions: practise this topic on examproblems.com.