Question

A human being suffering from Down’s syndrome shows trisomy of 21st chromosome. Mention the cause of this chromosomal abnormality.

Answer 1

hi dear

it is due to mutations

.due to environment

due to genetics

etc ..


bye


and please tell me how I am looking ??

Answer 2

Due to non-disjunction in down Syndrome,21st pair of chromosomes fail to separate during the process of oogenesis.

Hence, the egg instead to possessing 23 chromosomes possesses 24 chromosomes.

When the sperm & egg fuses with each other, the zygote has 3 copies of chromosome 21 that results in trisomy.