Alleles represent
(a) Different forms of a gene
(b) Same loci on homologous chromosomes
(c) Two or more forms
(d) All the above

Options

A. Different forms of a gene
B. Same loci on homologous chromosomes
C. Two or more forms
D. All the above

Answer

To solve the question regarding what alleles represent, we can analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding Alleles**:
- Alleles are defined as different forms of a gene that can exist at a specific locus on a chromosome.

2. **Analyzing Option (a)**:
- **Different forms of a gene**: This statement is correct. Alleles are indeed different versions of the same gene that can result in variations in a trait.

3. **Analyzing Option (b)**:
- **Same loci on homologous chromosomes**: This statement is also correct. Alleles occupy the same position (locus) on homologous chromosomes, which means they are found at the same location but can have different sequences.

4. **Analyzing Option (c)**:
- **Two or more forms**: This statement is correct as well. Alleles can exist in pairs (as in diploid organisms) or in multiple forms (as in polygenic traits), meaning there can be two or more variations of a gene.

5. **Analyzing Option (d)**:
- **All the above**: Since options (a), (b), and (c) are all correct, this option is also correct.

### Conclusion:
Based on the analysis of all the options, the correct answer is **(d) All the above**.

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