Question

what is chromosomes.explain how in sexually reproducing organisms the number of chromosomes in the progeny is maintained.

Answer 1

Chromosomes are thread-like structures located inside the nucleus of animal and plant cells.

Answer 2

In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Chromosomes are made of proteins and DNA. They are present in the nuclei of the cells.In sexually reproducing organisms, the gametes undergo meiosis and hence, each gamete contains only half set of chromosomes. When two gametes fuse, the zygote formed contains the full set of chromosomes.Hence, the formation of gametes by meiosis helps to maintain the number of chromosomes in progenies.