Introduction
- The basic unit of an organism’s body is a cell.
- Cells make up tissue, tissues come together to make an organ, organs constitute an organ system, which makes an organism.
- Therefore, to grow, reproduce, and repair, cells undergo division.
- Cell division is of two types – Meiosis and Mitosis.
Real-Life Examples:
What is Mitosis?
- In mitosis, a cell divides into two identical daughter cells.
- Mitosis is needed in multicellular living beings to grow.
- It helps repair the damaged cells.
- In organisms like bacteria, protists, and some plants, asexual reproduction is carried out using mitosis.
Importance of Mitosis
- Mitosis assists organisms in Growth, repair, and asexual reproduction.
Growth:
- When an organism grows from a young individual to an adult, the number and the size of cells increase.
- As mitosis gives two identical cells from a parent cell, it is used by the organisms to meet the need for an increasing number of cells.
Repair:
- Mitosis gives birth to new cells from parent cells.
- These new cells replace old, damaged, and dead cells at the site of injury, helping repair the tissue.
Asexual Reproduction:
- There are a few organisms that have the ability to reproduce using only one parent, known as asexual reproduction.
- In this, parents give birth to offspring that are exactly the same (clones).
- This happens with the help of mitosis.
Stages of the Cell Cycle
- In a cell cycle, there are two phases – Interphase + Mitosis
- Before the cell undergoes mitosis, it passes through interphase.
- Interphase is the longest phase, divided into three stages.
Stages of Mitosis
- Once the cell is prepared through various Interphase stages, it goes for cell division by mitosis.
- A cell crosses five stages to complete Mitosis.
Prophase:
- In G2 of Interphase, the cell continues to grow. For division into two equal daughter cells, the nucleus must divide.
- Thus, the nuclear membrane breakdown begins.
- Condensation of chromosomes begins.
- Spindle fibres emerge.
Metaphase:
- Spindle fibres get developed.
- Each chromosome gets attached to a spindle fibre.
- On these fibres, the chromosomes align themselves in the middle of the cell.
Anaphase:
- Cell elongation begins after the spindle fibres lengthen.
- The copies of chromosomes (sister chromatids) segregate and are pulled to opposite ends.
- This opposite movement of sister chromatids happens on the spindle fibres.
Telophase:
- The chromosomes meet at opposite poles and decondense.
- Nuclear membrane starts to develop around each set.
- This remarks the formation of new nuclei.
Cytokinesis:
- The cytoplasm of the elongated cell is divided by surface membrane.
- Formation of cell wall is observed in plant cells.
- With this, the cell division completes and gives two daughter cells.
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Book a Consultation →How does Mitosis Occur?
- For a cell to divide and give birth to new cells, it undergoes mitosis.
- Interphase prepares the cell by providing the necessary proteins, developing organelles, and DNA Replication.
- The cell enters Mitosis after completing interphase.
- As a cell must have a nucleus, in mitosis, its nucleus must divide; that is, karyokinesis must occur.
- The stages from Prophase to Telophase modify the cell.
- Telophase has the cell with new nuclei.
- Once it has two nuclei, it splits into clones. This splitting of the cell from the cytoplasm is known as cytokinesis.
Cancer Tumours
- Generally, cell division occurs only when needed.
- But, sometimes, uncontrollable cell division occurs.
- Such rapid cell division gives rise to the formation of lumps in the body, which are tumors.
- This leads to cancer, which can be deadly.
Asexual Reproduction
- Asexual Reproduction involves only one parent to produce offspring.
- The organism undergoes mitosis.
- The offspring produced are clones (genetically, they are the same).
- Thus, no variation as in sexual reproduction.
- This mode of reproduction is faster than sexual reproduction as no partner is needed.
- For example, strawberry plants, aphids, and female Komodo dragons.
Frequently Asked Questions
Solution:
A process by which a parent cell divides into two or more cells.
Solution:
Mitosis is a type of cell division that results in two identical daughter cells.
Solution:
Mitosis is essential for growth, repair of damaged tissues, and asexual reproduction.
Solution:
During interphase, the cell grows, replicates its DNA, and prepares for cell division. It consists of the G1, S, and G2 stages.
Solution:
The stages of mitosis are Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis.
Solution:
During Metaphase, chromosomes align in the middle of the cell and attach to spindle fibres.
Solution:
Cytokinesis is the final stage of cell division where the cell’s cytoplasm splits, forming two separate daughter cells.
Solution:
Cancer is caused by uncontrollable and rapid cell division, which leads to the formation of tumors.
