Chapter 9, Problem 1TYU

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely

1. A.    an animal cell in the process of cytokinesis.
2. B.     a plant cell in the process of cytokinesis.
3. C.     a bacterial cell dividing.
4. D.    a plant cell in metaphase.

Summary Introduction

Introduction:

Cell division takes place in two steps. The first step is the replication and segregation of the genetic material of the nucleus and that is called karyokinesis. The division of the cytoplasm is called cytokinesis.

Answer to Problem 1TYU

Correct answer:

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely a plant cell in the process of cytokinesis. Therefore, option (b) is correct.

Explanation of Solution

Reason for the correct statement:

The cytokinesis occurring in a plant cell is identified by the development of a cell plate near the center of the cytoplasmic region. The cell plate is developed by the accumulation of the materials for cell wall generation near the middle of the cell wall. The cell plate merges with the plasma membrane to form the two daughter cells.

Option (b) is given as “a plant cell in the process of cytokinesis”.

“During the cytokinesis of the plant cell, the cell plate formation takes place”, so it is the correct answer.

Hence, option (b) is correct.

Reasons for the incorrect statements:

Option (a) is given as “an animal cell in the process of cytokinesis”.

The process of cytoplasm division in the animal cell takes place by the process of cleavage. So, it is a wrong answer.

Option (b) is given as “a bacterial cell dividing”.

The bacteria divide into two daughter cells by replicating the genetic material, followed by the narrowing of the plasma membrane inwards to form the two identical daughter cells. So, it is a wrong answer.

Option (d) is given as “a plant cell in metaphase”.

At the time of metaphase, the chromosomes are seen near the center of the cell. There is no formation of the cell plate in the plant cell. So, it is a wrong answer.

Hence, options (a), (b), and (c) are incorrect.

Conclusion

The cell plate is formed during the cytokinesis of the cell division in the plant cell. The cell plate merges with the plasma membrane and the two identical daughter cells are formed.