In: Biology
Processes that regulate cell division in mammals include all of the following except:
rapid production of CDK enzymes that activate cyclin proteins | ||
different cyclins and CDKs act at different stages of the cell cycle to promote cell division. | ||
rapid degradation of cyclins after CDK activation | ||
activated cyclin-CDK complexes trigger cell cycle events. | ||
rapid production of cyclin proteins that activate CDK enzymes. |
Defects in cell signaling can lead to a cancerous cell due to all of the following except:
overproduction of signals that trigger cell division | ||
a defective signal-transduction protein that stays in the inactivated state and fails to trigger cell division. | ||
inactivation of proteins that promote apoptosis. | ||
a defective receptor that stays in the activated state and triggers cell division continuously. | ||
overproduction of a receptor that triggers cell division. |
1. The correct answer is Option a Rapid production of CDK enzymes that activate cyclin proteins.
Cyclin is a protein that is responsible for the control of the progression of cell cycle.The production of cyclin will activates the CDK enzymes. CDK alone is inactive but when it binds with cyclin causes the activation of the functional enzyme. In this option , it is given that the rapid production of CDK enzyme activates the cyclin proteins. But the truth is cyclin activates the CDK. Hence this is the answer.
Option B, C, D and E are not the right answers because these processes involved in the regulation of cell division in mammals.
2. The correct answer is Option B a defective signal- transduction protein that stays in the inactivated state and fails to trigger cell division
This option is an Exception because normally a defective signal transduction protein that stays in the activated state will helps to trigger the cell division. The signal transduction protein in an inactive state will not produce the formation of cancerous cells.
Option a is not the right answer because over production of cells that trigger cell division will leads to the formation of cancerous cells.
Options C, D and E are not the right answers because these all triggers the cell division and the formation of the cancerous cells.