Point mutation is induced by :-

Options

A. Adenine
B. Guanine
C. 3-cytosine
D. Bromouracil

Answer

To solve the question "Point mutation is induced by:", we will follow these steps:

### Step 1: Understand Point Mutation
Point mutation refers to a change in a single base pair in the DNA sequence. This can lead to a change in the amino acid sequence of a protein, which may affect the phenotype of an organism.

**Hint:** Remember that point mutations involve changes at a very small scale, specifically at the level of individual nucleotides.

### Step 2: Identify an Example of Point Mutation
A classic example of point mutation is sickle cell anemia, which is caused by a mutation where the amino acid glutamic acid is replaced by valine at the sixth position of the beta-globin chain due to a change in a single base pair.

**Hint:** Look for diseases or conditions that are known to be caused by specific mutations in the DNA sequence.

### Step 3: Determine the Inducers of Point Mutation
In the context of the question, we need to identify what can induce point mutations. One known inducer is 5-bromouracil, which is a structural analog of thymine.

**Hint:** Consider substances that mimic natural nucleotides and can incorporate into DNA during replication, leading to mutations.

### Step 4: Explain the Mechanism of 5-Bromouracil
5-bromouracil can pair with adenine instead of thymine during DNA replication. This mispairing can lead to a permanent change in the DNA sequence, resulting in a point mutation.

**Hint:** Think about how changes in base pairing can lead to errors in DNA replication and the consequences of those errors.

### Step 5: Conclusion
Based on the understanding that point mutations can be induced by specific chemicals, we conclude that 5-bromouracil is the correct answer to the question.

**Final Answer:** Point mutation is induced by 5-bromouracil.