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4-1 Coin Toss

Hybrid Cross Coin Toss


You can simulate Mendel's hybrid crosses by flipping two coins at the same time and observing how the pair lands. Each side of a coin represents a "coin gene" with heads the dominant trait.

The box below, called a Punnett Square, shows the possible combinations of the "coin genes" and their probabilities of landing with two heads, two tails, or one of each.

A Punnett square hybrid cross  
  • Toss a pair of coins 20 times.
  • Keep a tally of how they land.
  • Compare your results with the mathematical probabilities shown in the Punnett square.
  • How do you think your results might change if you toss the coins 100 times?


A Punnett square hybrid cross