What usually causes some species to become extinct? give two examples of species that are now extinct.

Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. a parakeet that is heterozygous for blue feathers (dominant) is crossed with a parakeet that is homozygous for white feathers (recessive). according to the punnett square for this cross, what percentage of offspring is predicted to have blue feathers? 25 percent 50 percent 75 percent 100 percent