Mitosis
What Is Mitosis?
Mitosis is a type of cell division that creates two identical cells from one original cell.
It is essential for:
- Growth
- Repair
- Asexual reproduction
💡 Key Concept: The daughter cells produced by mitosis are genetically identical to the parent cell.
Where Does Mitosis Happen?
Mitosis occurs in: ✔ Body cells (not gametes)
✔ Growth areas like skin, hair roots, and plant root tips
✔ Asexual reproduction in some organisms (e.g. bacteria, some plants)
The Cell Cycle
Cells go through a cycle of growth and division. It has three key stages:
1️. Growth and DNA replication
- Cell grows and increases organelles
- DNA is copied – forms X-shaped chromosomes made of two identical arms
2. Mitosis
- Chromosomes line up, are pulled apart, and move to opposite ends
- Nucleus divides
3. Cytokinesis
- The cytoplasm and membrane divide
- Two new identical daughter cells are formed
Steps of Mitosis (Simplified)
|
Stage |
What Happens |
|
Prophase |
Chromosomes condense, spindle fibres form |
|
Metaphase |
Chromosomes line up in the middle |
|
Anaphase |
Chromatids pulled to opposite ends |
|
Telophase |
New nuclei form at each end |
|
Cytokinesis |
Cell splits into two identical daughter cells |
💡 Remember: PMAT = Prophase, Metaphase, Anaphase, Telophase
Importance of Mitosis
✔ Enables organisms to grow
✔ Repairs damaged tissues
✔ Allows asexual reproduction
✔ Maintains the same number of chromosomes in each cell
Questions
- What is the purpose of mitosis?
- How many cells are produced by mitosis?
- Are the daughter cells genetically identical or different?
- During which stage do chromosomes line up in the middle?
- What does PMAT stand for?
Summary
- Mitosis is the process of cell division in body cells.
- It produces two identical daughter cells, each with the same number of chromosomes.
- Mitosis is part of the cell cycle, following DNA replication.
- It’s vital for growth, repair, and asexual reproduction.
- The stages of mitosis can be remembered using PMAT.