Question

Describe what is happening at the different stages of the cell cycle, its checkpoints, and two things that can happen if the cell cycle does not function correctly...

Answer 1

Answer:

cell cycle

Explanation:

A checkpoint is a stage in the eukaryotic cell cycle at which the cell examines internal and external cues and "decides" whether or not to move forward with division.

There are a number of checkpoints, but the three most important ones are:

The G_1

1

start subscript, 1, end subscript checkpoint, at the G_1

1

start subscript, 1, end subscript/S transition.

The G_2

2

start subscript, 2, end subscript checkpoint, at the G_2

2

start subscript, 2, end subscript/M transition.

The spindle checkpoint, at the transition from metaphase to anaphase.

Answer 2

Answer:

A checkpoint is a stage in the eukaryotic cell cycle at which the cell examines internal and external cues and "decides" whether or not to move forward with division.

To make sure that cell division goes smoothly (produces healthy daughter cells with complete, undamaged DNA), the cell has an additional checkpoint before M phase, called the G_2

2

start subscript, 2, end subscript checkpoint. At this stage, the cell will check:

DNA integrity. Is any of the DNA damaged?

DNA replication. Was the DNA completely copied during S phase?

If errors or damage are detected, the cell will pause at the G_2

2

start subscript, 2, end subscript checkpoint to allow for repairs. If the checkpoint mechanisms detect problems with the DNA, the cell cycle is halted, and the cell attempts to either complete DNA replication or repair the damaged DNA.

If the damage is irreparable, the cell may undergo apoptosis, or programmed cell death^2

2

squared. This self-destruction mechanism ensures that damaged DNA is not passed on to daughter cells and is important in preventing cancer.