Question

. What can be the disorders caused by the following type of aneuploidy –

A. 47 chromosomes with an extra copy of 21st chromosome

B. 47 chromosomes with an extra copy of X chromosome
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Answer 1

Question

. What can be the disorders caused by the following type of aneuploidy –

A. 47 chromosomes with an extra copy of 21st chromosome

B. 47 chromosomes with an extra copy of X chromosome

​

Answer: A. 47 chromosomes with an extra copy of 21st chromosome

Explanation:

Aneuploidy

An extra or missing chromosome is a common cause of some genetic disorders.

Answer 2

Answer:

Both A and R are true, and R is the correct explanation of A.

When the pollen tube gerninates on the stigma of a carpel, two pollen grains descend to the ovary, and they enter through the micropylar end.

One of the pollen fuses with the egg cell to form a diploid zygote.

While the other pollen fuses with the central cells (two polar nuclei) to form a triploid primary endosperm nucleus.

Further, the zygote develops into an embryo and the PEN develops into Endosperm cells.

Endosperm is nutritive and supportive in function, it nourishes the growing embryo.

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