Question

During the _____ phase of cell reproduction, protein synthesis occurs during the _____ phase of cell reproduction, rapid protein synthesis occurs as the cell grows to double in size.

a. G1 :G2

b. S : G2

c. G1 : S

d. G2 : S

Answer 1

During the __G1___ phase of cell reproduction, protein synthesis occurs during the _ S___ phase of cell reproduction, rapid protein synthesis occurs as the cell grows to double in size.

P.S:

G1 phase

G1 phase (G = gap) is the gap between completion of mitosis and the beginning of S phase (DNA synthesis). During this time, protein synthesis occurs and the cell grows to about double its original size. More organelles are produced, increasing the volume of the cytoplasm. If the cell is not to divide, it can pause its progress and enter a specialised resting state known as G0 (G zero), where it can remain for days, weeks or even years before resuming proliferation.

S phase

Following the G1 phase, the cell takes a decisive step and commits to DNA replication in a phase known as S phase (S = synthesis). During S phase, DNA is replicated to produce exactly two identical chromosomes. At the end of S phase, all of the chromosomes have been replicated; the amount of DNA in the cell has therefore effectively doubled. Typically, in a population of cells, about 30% will be in S phase at any one time.

G2 phase

Following DNA replication, the cell enters the G2 phase of the cell cycle, which lasts until the cell enters mitosis. Here, the cell undergoes significant biosynthesis to ensure necessary cell growth and production of microtubules required for mitosis. Inhibition of protein synthesis during G2 phase prevents the cell from undergoing mitosis.