Question

QUESTION 18

1. Following activation of a mitogenic signaling pathway, which of these events occur to promote cell division?

   	a.	Dephosphorylation of Retinoblastoma protein.
   	b.	Increased expression of p21.
   	c.	Phosphorylation of Myc.
   	d.	Inhibition of new protein synthesis.

1 points   

QUESTION 19

1. The slow rise of S cyclin levels throughout G1 phase is due to ___________, and the abrupt decrease is caused by ___________.

   	a.	import; export
   	b.	synthesis; mitosis
   	c.	transcription; proteolysis
   	d.	phosphorylation; translation

Answer 1

QUESTION 18
Following activation of a mitogenic signaling pathway, Immediate early gene Myc is produced. Upon phosphorylation, Myc promotes cell cycle entry by increasing the expression of genes encoding the G1 cyclins (D cyclins). This results in increased G1-Cdk activity.
Hence, option C is the correct answer.

QUESTION 19.

The slow rise of S cyclin levels throughout G1 phase is due to transcription, and the abrupt decrease is caused by proteolysis.

Hence, option C is the correct answer.