Chapter 14, Problem 4STP

Summary Introduction

Introduction :

A change in the sequence of DNA strand is termed as a mutation. Mutations are caused due to errors during DNA replication at the time of cell division. Exposure to mutagens, harmful radiations or viruses can also lead to mutation.

Answer to Problem 4STP

Correct answer :

The correct answer is option (A) chromosomal mutation.

Explanation of Solution

Explanation/justification for the correct answer :

Option (A) is chromosomal mutation. Chromosomal mutation occurs during crossing over at the time of meiosis. Here CCCCGAATT strand is mutated to CCTCGAATT. It can be resulted from reciprocal translocation between homologous chromosomes. Hence, this option is correct.

Explanation for incorrect answer :

Option (B) is deletion. In deletion mutation, a base is removed from the given DNA sequence leading to shift in frame. In the given sequence no base is deleted. Hence, this option is incorrect.

Option (C) is duplication. In duplication mutation, a base or sequence is repeated several times in the given DNA strand. In the given DNA sequence no duplication of base or sequence occurs. Hence, this option is incorrect.

Option (D) is frameshift. A frameshift mutation occurs due to insertion or deletion of base. In the given DNA sequence, no insertion or deletion occurs. Hence, this option is incorrect.