Question

The salivary gland chromosome dipteran larvae, are useful in gene mapping because

• A. These are fused
• B. These are much longer in size
• C. These are easy to stain
• D. They have endoreduplicated chromosomes

Answer 1

The correct option is D They have endoreduplicated chromosomes

Gene mapping is a powerful tool used to identify and record the location of genes and the distances between genes on a chromosome. The salivary gland chromosomes in the dipteran larvae are very useful in gene mapping because they have endoreduplicated chromosomes. These chromosomes are formed due to the process of endoduplication or endopolyploidy or endomitosis. In this process, the nuclear membrane does not rupture but chromosomes become double and they do not separate from each other. Thus the endoreduplicated chromosomes serve the best for gene mapping.