An increase in the concentration of MyoD would most likely lead to a(n) _______ of p21 expression, which would _______ the activity of cyclin-dependent kinases.
A) increase; increase
B) increase; decrease
C) decrease; increase
D) decrease; have no effect on
E) decrease; decrease

Question

Quizplus · Accepted Answer

MyoD is a transcription factor that activates the expression of genes involved in muscle differentiation, including p21. P21 is a cyclin-dependent kinase inhibitor that helps regulate the cell cycle. An increase in MyoD concentration would lead to an increase in p21 expression, which would inhibit the activity of cyclin-dependent kinases, thus decreasing their activity. Therefore, the answer is B: increase in MyoD concentration would lead to an increase in p21 expression, which would decrease the activity of cyclin-dependent kinases.

An Increase in the Concentration of MyoD Would Most Likely