Chapter 9, Problem 15A

Summary Introduction

To write:

Correct vocabulary terminthe given concept map.

Introduction:

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 spends most of the time in interphase. It is the stage in which a cell grows, carries out cellular activities and replicates. The next stage is mitosis in which cell’s nucleus and nuclear material divides. The last stage is cytokinesis in which the cytoplasm of the cell divided creating a new cell.

Answer to Problem 15A

Prophase

Explanation of Solution

The second stage in a cell cycle is mitosis in which cell’s nucleus and nuclear material divides. In this stage the replicated genetic material separates and the cell prepares to split into two cells. There are four stages in mitosis; prophase, metaphase, anaphase and telophase.

Prophase- This is the first stage in which a dividing cell spends most of the time. The nuclear membrane disintegrates and nucleolus disappears. The chromatin tightens and condenses into chromosomes. Chromosomes are shaped like an X. Each half of this X chromosome that was replicated in interphase is called sister chromatid. The sister chromatids are attached at the center with a structure called centromere. Mitoticspindle also begins to form between the poles of the cell.