You are studying a gene that controls ossicone (horn) length in giraffes. the wild-type long-ossicone allele (l) is dominant to the mutant short-ossicone (l) allele. however the l allele is only 60% penetrant. you cross two giraffes, one heterozygous and one homozygous recessive. what phenotypic progeny classes do you expect and at what frequencies (assume the penetrance of l applies equally to both homozygotes and heterozygotes).