Chapter 10, Problem 1U

Binary fission in prokaryotes does not require the

a. replication of DNA.

b. elongation of the cell.

c. separation of daughter cells by septum formation.

d. assembly of the nuclear envelope.

Summary Introduction

Introduction:

“Binary fission” in prokaryotes is a process of the division of the parent cell into two daughter cells. This leads to the division of the genetic material like chromosomes inside the cell. The nuclear envelope is absent in the prokaryotes and the chromosomes are present in a region of nucleoid inside the cytoplasm.

Answer to Problem 1U

Correct answer:

Binary fission in prokaryotes is the process of the separation of the chromosomes and their replication during the division of the parent cell into two daughter cells. The prokaryotes do not have a nucleus and therefore assembly of the nuclear envelope does not take place. Therefore, option d. is correct.

Explanation of Solution

Reason for the correct statement:

The prokaryotes do not have a nucleus the nuclear material is suspended in the cell and is termed as the nucleolus and the formation of the nuclear assembly does not take place during the process of binary fission.

Option d. is given as “assembly of the nuclear envelope”.

As, “the nucleus and nuclear envelope are absent in the prokaryotes therefore the process of binary fission involves only the replication and separation of the chromosomes after the division of the parent cell into two daughter cells” is the right answer.

Hence, option d. is correct.

Reasons for the incorrect statements:

Option a. is given as “replication of $\text{DNA}$”.

Replication of $\text{DNA}$ takes place during the process of binary fission. So, it is the wrong answer.

Option b. is given as “elongation of the cell”.

The elongation of the parent cell takes place before cell division. So, it is a wrong answer.

Option c. is given as “separation of daughter cells by septum formation”.

The septum is formed in between the two daughter cells which helps in the formation of the separate cells during binary fission. So, it is a wrong answer.

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

Conclusion

The binary fission process involves the division of the parent prokaryotic cell into two daughter cells with replication and separation of the chromosomes. The nucleus and nuclear envelope are absent in the prokaryotes and the chromosomes are present as nucleoid in the cytoplasm.