Question

A condition where an individual heterozygous for two linked genes (AaBb) possesses the two dominant genes on one chromosome of the homologous pair and the two recessive genes on the other, is said to be

• A. cis-arrangement
• B. trans-arrangement
• C. partly cis and partly trans
• D. Independently assorting genes

Answer 1

The correct option is A cis-arrangement

Linked genes are those genes that remain together and do not show independent assortment due to the physical closeness of the gene on the chromosome, hence remain clutched together along the chromosome.

If the dominant alleles (A and B) of both the linked genes are present on one chromosome, it is called a cis-arrangement and if the dominant allele of one pair and recessive allele of another is on one chromosome (A and b) then it is called trans-arrangement.
Independent assortment says the factor/alleles of genes assort independently while forming gametes. Linked genes do not show independent assortment, because the genes are located on the same chromosome and they tend to inherit in a group or unit unless there is any crossing over.