How do polytene chromosomes develop?


Do humans have polytene chromosomes?

While polytene chromosomes are most frequently found in insects, they are critical in diverse organisms from ciliates to plants to humans, and they play important roles in disease progression.

How do polytene chromosomes form?

Polytene chromosomes develop from the chromosomes of diploid nuclei by successive duplication of each chromosomal element (chromatid) without their segregation. The newly formed chromatids remain associated lengthwise and together form a cable-like structure, referred to as polytene chromosomes.

Why do the fruit fly larvae need polytene chromosomes?

Because each chromosome actually consists of many strands, they are called polytene (“many threaded”) chromosomes. … These bands provide visible landmarks that can be used to identify the location of a specific gene on the chromosome or the sites of chromosomal rearrangements.

What does polytene mean?

: relating to, being, or having chromosomes each of which consists of many strands with the corresponding chromomeres in contact.

What is polytene chromosome Class 11?

Polytene chromosomes are large chromosomes with thousands of strands of DNA. They provide a high level of functionality in certain organizations such as B. Salivary glands of insects. Polytene chromosomes have a series of dark stripes along their length, alternating light or medium stripes.

What is polytene chromosome Byjus?

Polytene chromosomes are giant chromosomes and are commonly found in the salivary glands of insects. … They are formed due to repeated duplication of chromosomes without separation. It is known as endomitosis. They have darkly stained bands and the region between two bands is lightly stained and is known as interband.

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What is the difference between Lampbrush chromosome and polytene chromosome?

The main difference between polytene and lampbrush chromosome is that polytene chromosomes occur in the salivary glands and other tissues of insects whereas lampbrush chromosomes occur in the oocytes of vertebrates except for mammals and some invertebrates.