There Are 4 Phases of Mitosis
Definition
Mitosis
Mitosis is a type of cell division in which a single parent cell divides to produce two genetically identical daughter cells, each containing the same number of chromosomes as the parent cell.
- Mitosis is divided into four distinct phases: prophase, metaphase, anaphase, and telophase.
- Each phase plays a critical role in ensuring the accurate distribution of chromosomes.
- Don't assume the phases of mitosis are separate.
- The process is continuous and are only divided into stages for clarity.
Prophase Prepares Cells for Division
Prophase is the first phase of mitosis, where chromosomes condense, the nuclear envelope breaks down, and the mitotic spindle begins to form.
- During prophase, the chromatin (loosely packed DNA) condenses into visible chromosomes.
- Each chromosome consists of two sister chromatids joined at a centromere.
- The nuclear envelope begins to break down, allowing the chromosomes to move freely in the cytoplasm.
- Microtubules assemble into a mitotic spindle, which will guide the chromosomes during division.
Remember: Prophase is all about preparation condensing DNA and assembling the machinery for division.
Metaphase Aligns the Chromosomes
Metaphase is the second phase of mitosis, where chromosomes align at the cell’s equator, attached to spindle fibers.
- Chromosomes line up along the metaphase plate (the cell’s equator).
- Spindle fibers attach to the kinetochores (protein structures) on the centromeres of each chromatid.
- This alignment ensures that each daughter cell will receive one copy of each chromosome.
Don’t confuse the metaphase plate with a physical structure, it’s an imaginary linewhere the chromosomes align.
