Mitosis
Cell division is the process by which a cell divides into two new cells. There are two main types of cell division: Mitosis and Meiosis.
Mitosis
Mitosis is the division of a single cell into two identical daughter cells.
It is a way for cells to grow, repair damaged tissues, and replace old or dying cells.
The cell goes through a series of steps:
Interphase (normal cell life)
Prophase (preparation)
Metaphase (lining up chromosomes)
Anaphase (chromosomes pulled apart)
Telophase (division of the cell)
Cytokinesis (division of the cytoplasm).
At the end of mitosis, each daughter cell has the same number of chromosomes as the original cell.
Mitosis – Detailed
Mitosis is similar to using a copy machine. Imagine your body’s cells as important documents, and each cell has its unique set of instructions. Mitosis is like putting one of these documents into a copy machine, creating two identical copies. The original document is like the parent cell, and the copies are the daughter cells. The purpose is to have more of the same information, just as mitosis helps the body grow, repair, and stay healthy by making more identical cells. It’s like making sure you always have fresh, updated copies of important documents for your body to function properly.
Interphase
This is the phase before mitosis officially begins.
The cell is in a resting state, carrying out its normal functions and preparing for division.
It consists of three sub-phases:
G1 (cell growth)
S (DNA synthesis, where the cell replicates its chromosomes)
G2 (further growth and preparation for mitosis).
Prophase
The chromatin (a complex of DNA and proteins) condenses into visible chromosomes.
The nuclear membrane starts to break down.
The mitotic spindle, a structure made of microtubules, begins to form. These microtubules will help move the chromosomes during cell division.
Metaphase
Chromosomes align at the cell’s equator, known as the metaphase plate.
The mitotic spindle is fully developed and attached to each chromatid of the chromosome.
Anaphase
The paired chromosomes (sister chromatids) are pulled apart by the mitotic spindle towards opposite ends of the cell.
Each chromatid is now considered an individual chromosome.
Telophase
Chromosomes reach the opposite poles of the cell.
The mitotic spindle disassembles, and a new nuclear membrane forms around each set of chromosomes.
The chromosomes begin to decondense back into chromatin.
Cytokinesis
Cytokinesis is the division of the cell’s cytoplasm and other organelles.
In animal cells, a cleavage furrow* forms, pinching the cell into two.
In plant cells, a new cell wall forms between the two daughter cells.
Ultimately, two identical daughter cells are produced.
After cytokinesis, the two new cells enter interphase, and the cycle can begin again. The result is the production of two cells, each with the same genetic material as the original cell.
* A cleavage furrow is like a pinching action that happens in animal cells during cell division. Imagine the cell as a balloon, and when it’s time to divide, a little crease or furrow forms around its middle. This furrow gradually gets deeper, and it’s like the cell is pinching itself in two. Eventually, the cell splits into two separate cells, each with its own set of instructions for what to do next. The cleavage furrow is like the finishing touch that completes the process of cell division in animals.
Uses of Mitosis
Growth:
Mitosis enables the increase in cell number, contributing to the overall growth of an organism.
Repair and Maintenance:
Mitosis replaces damaged or worn-out cells, supporting tissue repair and maintenance.
Asexual Reproduction:
Some organisms use mitosis as the primary method for asexual reproduction, producing genetically identical offspring.
Cell Renewal:
Mitosis is essential for the continuous renewal of tissues such as the skin, blood cells, and the lining of the digestive tract.
Embryonic Development:
Mitosis plays a crucial role in the early stages of embryonic development, shaping the structure of the developing organism.
Wound Healing:
Mitosis is involved in the rapid regeneration of cells to close wounds and restore normal tissue function after injuries.
