What is the meaning of Polyteny?

polyteny The condition of a chromosome, nucleus, or cell in which the DNA has repeatedly replicated, without subsequently separating (see endomitosis). This results in a cablelike giant chromosome, consisting of up to 1000 parallel chromatids and often showing conspicuous transverse banding.

What leads to Endoreduplication?

Endoreduplication (also referred to as endoreplication or endocycling) is replication of the nuclear genome in the absence of mitosis, which leads to elevated nuclear gene content and polyploidy.

Why are polytene chromosomes in salivary glands?

Structure. In insects, polytene chromosomes are commonly found in the salivary glands; they are also referred to as “salivary gland chromosomes”. The large size of the chromosome is due to the presence of many longitudinal strands called chromonemata; hence the name polytene (many stranded).

Are polytene chromosomes haploid or diploid?

The end product of the replication cycles is a nucleus with a haploid number of chromosomes, each containing up to 2,000 or more parallel strands. In the Collembola, however, the polytene chromosomes typically remain unpaired and the nuclei contain the diploid number (Fig.