During mitosis, human cells have 92 chromosomes present, though they are often described as 46 chromosomes with each duplicated into two identical sister chromatids. Once mitosis is complete, the cell divides into two identical daughter cells, each with 46 chromosomes, enclosed within their own nuclear membrane. This process, called cytokinesis, results in two clones of the original cell, each containing 46 monovalent chromosomes.
Here's a breakdown to clarify:
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Before Mitosis (Interphase): The cell has 46 chromosomes. Each chromosome replicates, resulting in two identical sister chromatids joined at the centromere. While the DNA has duplicated, the chromosome number is still considered 46 at this point, although there are 92 chromatids.
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During Mitosis: The 46 chromosomes (each consisting of two sister chromatids) are visible. Anaphase is when the sister chromatids separate, effectively doubling the chromosome count temporarily to 92 chromosomes as each chromatid is now considered an individual chromosome.
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After Mitosis (Cytokinesis): The cell divides, and each new daughter cell receives 46 chromosomes.
| Stage | Chromosome Count | Description |
|---|---|---|
| Interphase | 46 | Chromosomes are duplicated, each consisting of two sister chromatids. |
| Prophase | 46 | Chromosomes condense and become visible. |
| Metaphase | 46 | Chromosomes align at the metaphase plate. |
| Anaphase | 92 | Sister chromatids separate and move to opposite poles of the cell (each chromatid is now considered a chromosome). |
| Telophase | 92 (transient) | Chromosomes arrive at the poles and begin to decondense; the cell prepares for cytokinesis. |
| Cytokinesis | 46 in each cell | The cell divides into two daughter cells, each with 46 chromosomes. |
