NEET Biology question

A pollen grain of a plant has chromosome number 14. What will be the chromosome number and DNA content of a leaf cell of this plant during the following stages: G₁, S, G₂ and Metaphase?

(A)G₁: 2n=28, 2C; S: n=14, 2C; G₂: 2n=28, 4C; Metaphase: 2n=28, 4C
(B)G₁: 2n=28, 2C; S: 2n=28, 4C; G₂: 2n=28, 4C; Metaphase: 2n=28, 4CCorrect
(C)G₁: 2n=28, 2C; S: 2n=56, 4C; G₂: 2n=28, 4C; Metaphase: 2n=56, 4C
(D)G₁: n=14, 2C; S: n=14, 4C; G₂: n=14, 4C; Metaphase: n=14, 4C

Answer: (B)

Solution

A pollen grain is haploid, so n = 14, making the plant's somatic (leaf) cells diploid with 2n = 28 chromosomes — this chromosome number stays fixed at 28 throughout G₁, S, G₂ and metaphase of mitosis, since only the DNA amount per chromosome changes, not chromosome count. In G₁, DNA content is the unreplicated

See the full step-by-step solution

Create a free account to read the complete working, and practise questions like this in a timed test.

Create a free account

Question ID VK-127401