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Biology Punnet Squares Activities

Punnet Squares

Complete the following activities of punnet squares:
This resource is print only .

  1. a) Complete the following punnet square for a homozygous blue eyed male crossed with a homozygous


1 What percentage of offspring have blue eyes?
Explain why:

b) The offspring then cross to form another generation. Complete the punnet square to form the offspring.


i) What percentage have blue eyes?

  1. The gene for curly hair is C and is dominant. The gene for straight hair is s and is recessive.
    a) Design and draw a punnet square for heterozygous curly haired male crossing straight haired female.

    b) If the couple had 6 children how many are they likely to have with curly hair?
  2. Design three punnet squares to show how the offspring are likely to form genetically. The punnet squares are for
    blonde and brown hair. Brown hair is dominant and has the gene B. Blonde hair is recessive and has the gene b.

    a) The first punnet square should have no offspring with blonde hair. b)

    The second punnet square should have offspring with 50% blonde hair and 50% brown hair.

    c) The third punnet square should have offspring with 75% brown hair and 25% blonde hair.