Question

Select the incorrect match :
A) submetacentric chromosomes-L-shaped chromosomes
B) Lampbrush chromosomes- diplotene bivalents
C) polytene chromosomes-oocytes of amphibians
D) Allosomes – sex chromosomes

Answer 1

Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. The chromosome is made up of protein and deoxyribonucleic acid (DNA). There are four types of chromosomes based on the position of the centromere. These are metacentric, submetacentric, acrocentric, and telocentric.

Complete answer:
A chromosome is a condensed form of chromatin that is made up of proteins and DNA present in the nucleus of cells, humans have 22 pairs of chromosomes, plus the two sex chromosomes that is a total of 46. The word chromosome was originally coined from the Greek word 'chroma' meaning color and 'Soma’ meaning body.
Option A: Submetacentric chromosomes: L-shaped chromosomes: submetacentric chromosome is a chromosome in which centromere is located near the middle of the chromosome. As a result, the chromosomal arms are slightly equal in length and may also form an L shape.
Option B: Lampbrush chromosomes- diplotene bivalents: lampbrush chromosomes of most animals except mammals. Lymphbrush chromosomes are a transitory structure that exists during an extended diplotene of first meiotic division in females. It is involved in the production of masked mRNA for early development. The giant granular loops could either be the sides where mRNA are packaged or they could be a site where specific alterations of the deoxyribonucleic acid fiber take place.
Option C: Polytene chromosomes -oocytes of amphibians: polytene chromosomes are large chromosomes which have thousands of DNA strands. They provide a high level of function in certain tissues such as the salivary glands of insects.
Option D: Allosomes - sex chromosomes: allosomes are sex chromosomes, it differs from an ordinary autosome in size and behavior.
Thus, the answer is option C: polytene chromosomes-oocytes of amphibians.

Note: Polytene chromosomes are giant chromosomes which are usually seen in two-winged flies. They result due to repeated rounds of DNA replication without any cell division.