Question

When root tip cell have $2n=20$ chromosomes, then number of chromosomes in endosperm will be

• A. $10$
• B. $20$
• C. $30$
• D. $40$

Answer 1

Answer: (C)

Diploidy (2n) refers to having two sets of chromosome, with one member of each chromosome pair derived from the ovum and one from the sperm.

Haploidy (n) refers to the state of having the half of the set of chromosomes as in a germ cell or a gamete.

Triploidy (3n) is a rare chromosomal abnormality when there is an extra pair of the chromosome in their cells. Example: endosperm in plants.

Therefore, 2n = 20 chromosomes

n = 10 chromosomes

Since endosperm is a triploid (3n). Therefore 3n = 3 * 10 = 30.

So, the correct option is '30'.