Question

Lampbrush loops and polytene puffs are

• A. Analogous
• B. Homologous
• C. Both A and B
• D. Have no relation

Answer 1

The correct option is A Analogous

Lampbrush chromosomes are a special form of chromosome found in the growing oocytes (immature eggs) of most animals, except mammals. They were first described by Walther Flemming in 1882. A given loop always contains the same DNA sequence, and it remains extended in the same manner as the oocytes grows. These chromosomes are producing large amounts of RNA for the oocyte, and most of the genes present in the DNA loops are being actively expressed.
Polytene chromosomes are over-sized chromosomes which have developed from standard chromosomes and are commonly found in the salivary glands of Drosophila melanogaster. Specialized cells undergo repeated rounds of DNA replication without cell division (endomitosis), to increase cell volume, forming a giant polytene chromosome. Polytene chromosomes form when multiple rounds of replication produce many sister chromatids that remain synapsed together.
Lampbrush chromosomes and polytene puffs are analogous in nature because they are performing a similar function but having a different evolutionary origin.