AP BIOLOGY

CELL DIVISION

THE CELL CYCLE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
____ is a critical point where stop and go signals can regulate the cycle
A
Metastasis
B
Checkpoint
C
Malignant
D
Benign
Explanation: 

Detailed explanation-1: -A checkpoint in the cell cycle is a critical control point where stoop and go-ahead signals can regulate the cycle. Animal cells generally have built-in stop signals that half the cell cycle at checkpoints until overridden by go-ahead signals.

Detailed explanation-2: -The main cell cycle checkpoints are the G1/S checkpoint, the intra-S checkpoint, and the G2/M checkpoint [60]. The transition through stages of the cell cycle is regulated by the action of cyclin-dependent kinases, which are key targets for modulations induced by different cellular stimuli, including DNA damage.

Detailed explanation-3: -The G1 checkpoint. The G1 checkpoint is located at the end of G1 phase, before the transition to S phase. If cells don’t pass the G1 checkpoint, they may “loop out” of the cell cycle and into a resting state called G0, from which they may subsequently re-enter G1 under the appropriate conditions.

Detailed explanation-4: -Progression through these checkpoints is largely determined by the activation of cyclin-dependent kinases by regulatory protein subunits called cyclins, different forms of which are produced at each stage of the cell cycle to control the specific events that occur therein.

There is 1 question to complete.