Question

Explain how in sexually producing organisms the no. Of chromosomes in the progeny remains the same as that of the parents

Answer 1

Ciao,
this happends due to meiosis or reduction division .in it gametes are formed and meiosis ensures that each of them is haploid means having half of the number of chromosomes from their parents.so both of the gametes ( egg and sperm) have half chromosomes in each when they combine two halves makes full set of chromosomes as that in their parents.so in this way chromosome no. remains same .
hope it helps stay blessed☺

Answer 2

Chromosomes are thread like structure,made of proteins and DNA,found in the nucleus at the time of cell division.

In sexually reproducing organisms,the gametes undergo meiosis,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.