Question

An egg cell has 5 picogram of genetic material in its nucleus. What amount of the material will be present in the organism at the end of G2-phase of mitosis?
a. 5 gm
b. 5 picogram
c. 10 picogram
d. 20 picogram

Answer 1

Hint: In preparation for cell division, the cell cycle is the ordered sequence of events that occur in a cell. It "decides" whether it should join the cell cycle and divide depending on the stimulatory and inhibitory signals a cell receives.

Complete answer:
> Option A is incorrect. If the egg is haploid and contains 5 picograms of genetic material. It is an animal comprising 10 picograms of genetic material and must be diploid. The genetic material becomes two-fold in the S process. At the end of the G2-phase of mitosis the cell must undergo a hundred trillion cycle to generate 5 gm of the genetic material.

> Option B is incorrect. If the egg is haploid and contains 5 picograms of genetic material. It was arrested in phase G1 and can either enter the phase G0 or re-enter the cycle of cells. Therefore, in this instance, 5 picograms will be generated.

> Option C is incorrect. The production of proteins, the number of organelles (such as mitochondria, ribosomes) are increased during the G1 process, grows in size. The egg is haploid and thus contains 5 picograms of genetic material. It is an animal comprising 10 picograms of genetic material and must be diploid.

> Option D is correct. An egg is haploid, and it comprises 5 picograms of genetic material. It is an animal comprising 10 picograms of genetic material and must be diploid. In the S phase, the genetic material is doubled, so 20 picograms would be the sum of genetic material in the G2 phase.

Hence, The correct answer is option (D).

Note: Cells use unique proteins and signalling checkpoint mechanisms to make sure the cell cycle is working properly. The cell is forced to undergo programmed cell death or apoptosis if DNA damage or abnormalities. However, abnormal proteins or genes that cause malignant cell transformation, which can lead to cancer, can sabotage the cell cycle and its checkpoint systems.