Chapter 10, Problem 3STP

Summary Introduction

Introduction:

A cell grows until it reaches its size limit, then it either stops growing or divides. Most cells undergo division. Cell division helps a cell to reproduce and makes the organism grow and heal certain injuries.

Answer to Problem 3STP

Correct answer :

The correct answer is option D. mitosis

Explanation of Solution

Explanation/justification for the correct answer:

Option D.Mitosis- The second stage in a cell cycle is mitosis in which cell’s nucleus and nuclear material divides. In this stage the cell’s 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 nuclear membrane disintegrates, nucleolus disappears, chromosomes condense and mitotic spindle begins to form between the poles of the cell.

Metaphase- In this stage the chromosomes attach to mitotic spindle and align along the equator of the cell.

Anaphase- In this stage, the microtubules shorten, moving the chromosomes to opposite poles.

Telophase- This is the last stage in which the chromosomes reach the poles of the cell, nuclear envelope forms again, nucleolus reappears and chromosomes decondense.

Explanation for incorrect answer:

Option 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. The entire sequence of events in the life of a eukaryotic cell is called cell cycle. Hence this is not the correct option.

Option B. cytokinesis-The last stage of cell cycle is cytokinesis in which the cytoplasm of the cell divided creating a new cell. The nuclear material and nucleus does not divide in this stage. Hence this is not the correct option.

Option C. interphase- A cell spends most of the time in interphase. It is the stage in which a cell grows, carries out cellular activities and DNA replicates. The nuclear material and nucleus does not divide in this stage. Hence this is not the correct option.