Cell Division: Mitosis and Meiosis
Cell division is a type of cell process that happens when a parent cell divides into two daughter cells. All the cells reproduce by splitting into two, where each parental cell gives rise to two daughter cells. These newly formed daughter cells could themselves divide and grow, giving rise to a new cell population that is formed by the division and growth of a single parental cell and its descendant.
What is Cell Division?
The process by which a cell divide into two clones i.e., genetically identical cells. The genetic material is transferred from one generation to another with the help of cell division. The time duration of the cell cycle depends on the species, normally an Ek cell takes 24 hrs. to complete one cell cycle. The cell cycle is classified on the basis of the cell is divided. Normal cells are divided via mitosis, while germ cells divide via meiosis.
Types of Cell Division
Cell Division is broadly classified into 2 subtypes:
- Mitosis: Equational Division
- Meiosis: Reductional Division
- Binary Fission
Whenever, we talk about cell division we refer to mitosis, which means the process of making new body cells.
Mitosis is a fundamental process for life, during this process, a cell duplicates all of its content including the chromosomes, and splits to form two identical daughter cells. They make exact copies of the parent cell. All the genetic material and cytoplasm divide equally, that’s why mitosis is also known as Equational division.
Also Read: Mitosis
Phases of Mitosis
- Interphase: It is the period when a cell is getting ready to divide and start the cell cycle. During this time, cells are gathering nutrients and energy.
- Prophase: There are two stages early and late prophase. In the early prophase, the cell initiates cell division by breaking down and building other components, and then chromosome division starts. In the late stages, the mitotic spindle starts to organize the chromosomes.
- Metaphase: Starts when the mitotic spindle organizes all chromosomes and lines them up in the middle of the cell to divide, at the metaphase plate. At this stage of metaphase, the two kinetochores of each chromosome should be attached to microtubules from opposite spindle poles.
- Anaphase: In this stage, the chromatids separate from each other and move toward the opposite poles of the cell. The protein glue that holds them breaks and allows them to separate.
- Telophase: In this stage, the cell is almost divided and starts to re-establish its normal cellular structures as cytokinesis takes place. The mitotic spindle breaks down into its building blocks and two new nuclei are formed, one for each set of chromosomes.
- Cytokinesis: In animal cells, cytokinesis is contractile. There’s a pinch-like formation within the cell that divides it in two like a coin purse with a ‘drawstring’. The “drawstring” is a band of actin protein filaments. The pinch crease is called the cleavage furrow. Plant cells can’t be divided like this as they have a rigid cell wall and are too stiff. A cell plate forms down the middle of the cell which splits the daughter cells.
In meiosis, the cell ensures that humans have the same number of chromosomes in each generation, it is a two-step process that reduces the number of chromosomes to half from 46 to 23- to form sperm and egg cells. When the two, the sperm and the egg cell combine resulting in the embryo which will have the usual 46 chromosomes. Meiosis also allows generic variation through a process of gene shuffling while the cells are dividing.
Meiosis has two cycles of cell division, called Meiosis I and Meiosis II. Meiosis I halves the number of chromosomes and is also when crossing over happens. Meiosis II halves the amount of genetic information in each chromosome of each cell. The ultimate result is four daughter cells called haploid cells. During the next stages of meiosis, this DNA will be switched around during genetic recombination and then divided between four haploid cells. Therefore, Mitosis helps us grow and Meiosis tells us why we are unique.
Also Read: Meiosis
Binary fission is a type of reproduction occurred in prokaryotic cells. It is a process in which a bacteria cell divides into 2 cells via the duplication of the genetic material into 2 cells.
Differences Between Mitosis and Meiosis
The main difference between mitosis and meiosis is that mitosis is the equational division which means that the cell divides into two equal daughter cells. Meiosis is known as the reductional division. Meiosis normally occurs in the gamete cell. In meiosis cells, genetic material reduces to half (2n ⇢ n).
FAQs on Cell Division
Q1. What is Meant by Binary Fission?
When single-celled organisms like bacteria replicate themselves for reproduction it is called binary fission.
Q2. What are the 3 types of Cell Division?
The three type of cell division are:
- Binary Fission
Q3: What is the Function of Cell Division?
The main function of cell division is to generate new cells which will help in growth, preparing the damaged cell of the body.
Question 4: What is Cell Growth called?
Cell proliferation is a process in which the number of cells is increased via cell division. Cell division is also known as cell proliferation.
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