Question

Ex plain how in sexually reproduc ing organisms the number of chromosome s in the progeny is maintained.

Answer 1

in sexually reproducing organisms the no of chromosomes are maintained as:
 the male sperm contains only 23 chromosomes and the female egg also contains only 23 chromosomes and so when zygote gets formed the chromosomes add up to become 46 in number.

Answer 2

In sexually reproducing organisms, the gametes undergo meiosis, and hence, each gamete contains only half a 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 the progeny.

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