Square used to explain genetic traits
. The sperm
is listed on the left and the egg
's on the top, then the traits are crossbred
. For example, the sperm genotype that determines the sex of a baby is XY
and the egg genotype is XX
. This leads to this Punnett Square:
X XX XX
Y XY XY
This means that there's a 50% chance that the baby will be a boy (XY) and a 50% chance that it will be a girl (XX).
The Punnett Square sometimes gets more complicated, but the idea remains the same. It works for all types of plants and animals, but some genes are a little too complicated to use a Punnett Square for.