In a heterozygote for two linked genes,both dominant alleles are on one chromosome and both recessive alleles are on another chromosome.The genes are said to be in
A)recombination.
B)repulsion.
C)cis.
D)trans.

Question

Quizplus · Accepted Answer

When both dominant alleles are on one chromosome and both recessive alleles are on another chromosome, the genes are said to be in cis. This means that they are on the same chromosome and are not undergoing recombination or crossing over. Choice A (recombination) is incorrect because recombination involves the exchange of genetic material between homologous chromosomes during meiosis. Choice B (repulsion) is incorrect because this term is sometimes used to describe a heterozygote in which one chromosome carries both dominant alleles and the other carries both recessive alleles, but this is not the same as the genes being in cis. Choice D (trans) is incorrect because this term describes a situation in which the dominant allele of one gene is on the same chromosome as the recessive allele of another gene, but this is not the same as the genes being in cis.

In a Heterozygote for Two Linked Genes,both Dominant Alleles Are