What are micro–mutations

Options

A. Union of chromosomes
B. Reduction of chromosomes
C. Changes in genes
D. Polyploidy

Explanation

### Step-by-Step Solution:

1. **Definition of Micromutations**: Micromutations are small-scale mutations that occur at a specific location in the DNA sequence. They are often referred to as localized mutations.

2. **Characteristics of Micromutations**: These mutations typically involve changes at a single gene locus, meaning that they affect only one specific gene rather than multiple genes or entire chromosomes.

3. **Types of Micromutations**: Micromutations can include various types of genetic changes such as point mutations (where a single nucleotide is altered), insertions, or deletions of small segments of DNA.

4. **Distinction from Other Mutations**: Unlike larger-scale mutations such as polyploidy (which involves changes in the number of chromosomes) or chromosomal rearrangements, micromutations are confined to minor alterations within a gene.

5. **Conclusion**: Therefore, micromutations are defined as changes in gene sequences at a single gene locus, making option C (changes in gene) the correct answer when considering the options provided.