Why shouldn't you cross a parrot with a shark answer key?

This is because it would not be possible. The resulting zygote from the fusion of gametes from both species would probably not be able to grow and develop into a normal organism. This is because the two are two different species and are reproductively isolated. A shark has 82 chromosomes while a parrot has 80 chromosomes and do not share homologous chromosomes (alleles).