Question

Select the correct option:The DNA content of individual cells and the number of cells in each phase of a " cell cycle" can be determined using flow cytometry. Which of the following combinations of "phase of a cell cycle and its corresponding DNA content" can be considered normal?
(i) Diploid cells found in the $G_0$ or $G_1$ phase.
(ii) Cells with twice the normal DNA content in the early M phase.
(iii) Cells with intermediate amounts of DNA in the S phase.
(iv) Cells with twice the normal DNA content in the $G_2$ phase.

• A. (i) and (ii)
• B. (ii) and (iii)
• C. (iii) and (iv)
• D. (i), (ii), (iii) and (iv)

Answer 1

The correct option is D (i), (ii), (iii) and (iv)

The sequence of events which occur during cell growth and cell division are collectively known as the cell cycle. The cell cycle is completed into two steps; the interphase which is again divided into G₁ and G₂ phase and the M phase which is the mitotic phase in which karyokinesis and cytokinesis take place.

In G₁ phase of interphase synthesis of the content of the cell is there growth and cell take place. During the S phase, the DNA replication takes place and its amount becomes double. During the G₂ phase, the chromosome condensation factor appears and DNA repair occurs.

So, the correct option is '(i), (ii), (iii) and (iv)'