NEET Solved Paper 2014 Question 16
Question: During which phase(s) of cell cycle, amount of DNA in a cell remains at 4C level if the initial amount is denoted as 2C? [AIPMT 2014]
Options:
A) $ G _0 $ and $ G _1 $
B) $ G _1 $ and S
C) Only $ G _2 $
D) $ G _2 $ and M
Show Answer
Answer:
Correct Answer: C
Solution:
- During the S or synthetic phase, the DNA content doubles, i.e., from 2C to 4C for all diploid cells. The $ G _2 $ phase follows the 5-phase and is called second growth phase or pre mitotic gap phase. In $ G _2 $ phase the synthesis of DNA stops therefore, the DNA level remains 4C if initial was 2C. However, the formation of RNA and protein continues as they are required for the multiplication of cell organelles, spindle formation and cell growth. This amount becomes half (i.e.,) 2C only during anaphase (in mitosis) when chromosomes separate.
