Chapter 9, Problem 12STP

Summary Introduction

To explain:

What the cell does at the checkpoint indicated by the stoplight in the given diagram..

Introduction:

The given diagram depicts a cell cycle. Cells reproduce by a cycle of growing and dividing called the cell cycle. There are three main stages of a cell cycle; interphase, mitosis and cytokinesis.A cell cycle has built in checkpoints that monitor the cycle and can stop the cycle if something goes wrong. There are three checkpoints; G₁, G₂ and M to control the speed at which a cell moves through a cell cycle.

Answer to Problem 12STP

The G₂ checkpoint located at G₂/ M interphase sees if DNA has replicated properly and completely in the S phase. Only then will the cell advance to next stage.

Explanation of Solution

The following diagram is given.

  

According to the diagram the stoplight is given at G₂/ M interphase. This checkpoint sees if DNA has replicated properly and completely in the S phase. Only then will the cell advance to next stage. It this checkpoint detects any error in DNA replication, it will stop the cell cycle and the cell will proceed to complete replication. If the DNA is damaged or cannot be repaired, cells will undergo apoptosis.