Answer :
Chromosomes contain DNA which contains genetic information needed to be able to build the onion.
It is necessary for onion cells to contain chromosomes because chromosomes contains the genetic material called DNA.
What is deoxyribonucleic acid (DNA)?
DNA is a self-replicating material which is present in nearly all living organisms as the main constituent of chromosomes. It carries genetic information and inherit information from parents to progeny .
Each onion cell consists of 8 chromosomes, whereas a diploid meiocyte of an onion cell consists of 16 chromosomes.
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