Question

Allosomes are
A. Bead like structure on chromosomes
B. Sex chromosomes
C. Rounded bodies
D. Node like structure on chromosomes

Answer 1

Hint: Allosomes are those which vary from an autosome in terms of size, structure, etc. Chromosomes that contain the same number of genes are known as autosomes.

Complete answer:
The 23rd pair of chromosomes is called autosomes which consists of a pair of X chromosomes in females and one X and Y chromosome in males.
These sets of chromosomes are also known as sex chromosomes as they help in determining the sex of an individual and are involved in sexual reproduction.
Males have 22 pairs of homologous chromosomes, whereas 23 pairs of homologous pairs are present in females. In the ova, the X chromosome is present on the 23rd chromosome whereas, in men, X or Y can be present in individual sperm.
Autosomes are not involved in sexual reproduction and thus, they do not play any role in the genetic determination of an individual.

Additional information: Each autosome consists of many thousands of genes, each of which performs a special function in the organism's cells. Under normal conditions, each chromosome follows a “map” that is used across individuals in the species.
This permits cells to “know” where to start gene expression when they want to express a certain gene.

Hence, the correct option is (B) Sex chromosomes.

Note: Genes present on the allosomes are called sex-linked genes as they help in determining the sex of an individual and are involved in inherited and genetic expressions.