German cockroaches, bulging eyes, bu, are recessive to normal eyes, bu , and curved wings, cv, are recessive to straight wings, cv . both traits are encoded by autosomal genes that are linked. a cockroach has genotype bu bu cv cv, and the genes are in repulsion. which set of genes will be found in the most common gametes produced by this cockroach?
(E) bu cv+
Linkage is the phenomena in which two genes present on same chromosome have a tendency to get inherited together.
It is given that the two autosomal genes are linked and in repulsion. This means that the dominant allele of one gene is linked to the recessive allele of another gene and vice versa.
Hence, the parental type gametes will have bu cv+ and bu+ cv combination. Since in linkage parental gametes always appear in higher numbers than recombinant gametes, out of the given options bu cv+ set of genes will be present in most gametes produced by this cockroach.
E. bu cv+
Given, that bu+ and cv+ are dominant alleles whereas bu and cv are recessive alleles of the respective genes. In repulsion, the chromosome has one dominant and one recessive allele of the linked genes. According to it, if the German cockroach has bu+bu cv+cv genotype, it should be present in bu+cv/bucv+ arrangement. Thus the parental gametes from this genotype would be bu+cv and bucv+. Recombinant gametes will be bucv and bu+cv+.
Since parental gametes are produced more in number than recombinant gametes in linkage, bu+cv and bucv+ will be the most common gametes. Hence, out of the given options bucv+ set of genes will be present in the most common gametes produced by this cockroach.