Question

In Haplopappus gracilis, number of chromosomes in cells of nucellus is 4. What will be the chromosome number in Primary endosperm cell?

Options

• 8

• 12

• 6

• 2

Answer 1

6

Explanation:

In Haplopappus gracilis, if the number of chromosomes in the cells of the nucellus is 4 (diploid, 2n = 4), then:

• The haploid (n) chromosome number would be 2.
• The Primary endosperm cell is formed as a result of the fusion of one male gamete (n) with two polar nuclei (n + n) in the process of double fertilization, making it triploid (3n).

Calculation: 3n = 3 × 2 = 6 chromosomes

Therefore, the chromosome number in the Primary endosperm cell will be 6.