What are chromosomes? Can you explain how in sexually reproducing organisms the number of chromosome in the progeny is maintained?

Hello Amartya, A chromosome is a DNA molecule with part or all of the genetic material (genome) of an organism. Prokaryotes usually have one single circular chromosome, whereas most eukaryotes are diploid, like humans. Chromosomes in eukaryotes are composed of the chromatin fibre. Chromatin fibre is made of nucleosomes. A nucleosome is a histone octamer with part of a longer DNA strand attached to and wrapped around it. Chromatin fibre, together with associated proteins is known as chromatin. Chromatin is present in most cells, with a few exceptions, for example, red blood cells. Occurring only in the nucleus of eukaryotic cells, chromatin contains the vast majority of DNA, except for a small amount inherited maternally, which is found in the mitochondria. * two cells combine to form a single cell male cell + female cell = Baby cell sperm + Ovum= zygote If the cells combine directly to form zygote, the zygote will have 96 pairs of chromosomes (46 from male+46 from female) To avoid this, male sperm and ovum are produced having only 23 pairs of chromosomes(called as haploid cells) This process is called as MEIOSIS. So when they combine they form 23+23= 46 pairs of chromosomes in offspring(zygote) diploid cells = 46 chromosomes haploid cells = 23 chromosomes 2 haploid cells combine to form single diploid cell (offspring) I hope this answers your question to your satisfaction. If so, kindly upvote this answer. If you have any further questions, kindly revert.

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