There arIn steps 4 and 5, you are shown the offspring first. Here, you will use a Punnett square to determine actual results of a cross between offspring. the actual age of the offspring. the genotypes of the parents. how genes are expressed.e four different combinations of offspring genotypes in every Punnett square. Fill in the blanks below to complete the ratio for the Punnet square shown to the right. black fur:white fur = :