Gene mutations occurs in
(a) Chromosomes
(b) DNA
(c) RNA
(d) Nucleus

Options

A. Chromosomes
B. DNA
C. RNA
D. Nucleus

Answer

To solve the question regarding where gene mutations occur, we can follow these steps:

### Step 1: Understand what gene mutations are
Gene mutations are changes in the nucleotide sequence of DNA. These changes can affect how genes function and can lead to variations in the traits of organisms.

**Hint:** Think about the basic definition of gene mutations and their significance in genetics.

### Step 2: Analyze the options provided
The options given are:
- (a) Chromosomes
- (b) DNA
- (c) RNA
- (d) Nucleus

We need to determine where gene mutations specifically occur.

**Hint:** Consider the relationship between genes and the molecular structures listed in the options.

### Step 3: Identify the relationship between genes and DNA
Genes are segments of DNA that code for proteins. Therefore, any mutation that occurs at the gene level must occur in the DNA itself, as genes are composed of DNA.

**Hint:** Recall that genes are made up of DNA and that mutations affect the sequence of nucleotides in DNA.

### Step 4: Evaluate the other options
- **Chromosomes**: While genes are located on chromosomes, mutations occur at the DNA level, not at the chromosomal level.
- **RNA**: RNA is a product of DNA transcription and is not where mutations occur.
- **Nucleus**: The nucleus is the cellular structure that contains DNA, but mutations occur within the DNA itself, not in the nucleus as a whole.

**Hint:** Think about the structural hierarchy of genetics: DNA → Genes → Chromosomes.

### Step 5: Conclude with the correct answer
Based on the analysis, the correct answer is (b) DNA, as gene mutations occur in the DNA sequence that makes up the genes.

**Final Answer:** (b) DNA