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
♂ Rr♀ RrRrrR

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

AaBb × aaBb
P =
5.Hard
AA?AaAaaap (A)q (a)p (A)q (a)q² = 0.04N = 10000

In a population of 10000 in Hardy–Weinberg equilibrium, 4% show a recessive trait. How many individuals N are expected to be homozygous dominant?

N = 10000q² = 0.04
N =
6.Hard
AAAa?Aa?aap (A)q (a)p (A)q (a)q² = 0.04f = ?

A recessive condition affects 4% of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?

q² = 0.04
f =

Answer key

  1. 1. r × r
  2. 2. P = 0.5
  3. 3. P = 0.375
  4. 4. P = 0.375
  5. 5. N = 6400
  6. 6. f = 0.32

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