The significance of mitosis is to keep the chromosome number constant in a species.

Answer

**Step-by-Step Solution:**

1. **Understanding Mitosis**: Mitosis is a type of cell division that occurs in somatic (body) cells, which are all the cells of an organism except for the reproductive cells (gametes).

2. **Purpose of Mitosis**: The primary purpose of mitosis is to allow for growth, development, and tissue repair in an organism. It ensures that when a cell divides, the resulting daughter cells are genetically identical to the parent cell.

3. **Chromosome Number Maintenance**: During mitosis, if a diploid cell (which has two sets of chromosomes) undergoes division, it will produce two diploid daughter cells. Similarly, if a haploid cell (which has one set of chromosomes) undergoes mitosis, it will produce two haploid daughter cells. This means that the chromosome number remains constant in the resulting cells.

4. **Equational Division**: Mitosis is often referred to as an equational division because it divides the genetic material equally between the two daughter cells. Each daughter cell receives an identical set of chromosomes, maintaining the chromosome number.

5. **Conclusion**: Therefore, the statement that "the significance of mitosis is to keep the chromosome number constant in a species" is true. Mitosis ensures that the chromosome number remains stable across generations of cells within an organism.

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