Question

Refer to the given diagram showing cell cycle and answer the questions that follow.
(i) if the chromosome number at X is 2n, what will be the number of chromosomes at Y?
(ii) Which phase is the longest phase of M phase?

• A. (i)-2n, (ii)-Telophase
• B. (i)-4n, (ii)-Metaphase
• C. (i)-2n, (ii)-Prophase
• D. (i)-4n, (ii)-Anaphase

Answer 1

The correct option is C (i)-2n, (ii)-Prophase

X is G${}_1$ phase, Y is S phase and Z is G${}_2$ phase.

In S phase the amount of nucleic acid doubles but the number of chromosomes remains the same.

The longest phase in Mitosis is Prophase.

So, the correct option is '(i)-2n, (ii)Prophase'