Cell srtucture and cell division

Cell structure and cell division:

In today’s talk, we will discuss in detail cell identity, cell structure, and cell division in plant cells and animal cells. First, I will discuss cell introduction, then cell division, along with some other important questions and answers about cells.

What is cell?

The bodies of all plants and animals are made up of cells. A cell is the unit of body structure. Cells are the basic building blocks of the ‘overall structure’, ‘division function’, and ‘line of heredity’ of a plant or animal. The structural unit of this cell is the protoplasm. However, some animals are made up of only one cell, such as amoeba. Even the reproduction of this amoeba is completed by dividing its cells into two parts.

Some bacteria are also found to be unicellular. Just as a building is built by arranging many bricks in a row, the body is formed by arranging countless numbers of cells coming together. Some cells with the same characteristics are united to form tissue. And many tissues are made up of each organ. Scientist Robert Hooke discovered the cell in 1665.

Scientists Matthias Jakob Schleiden and Theodor Schleiden together discovered the cell theory in 1839 that “all living things are composed of one or more cells, and all cells derive from some pre-existing cell.”

Types of cells:

There are generally two main classes of cells.
1) Prokaryotic and
2) Eukaryotic.

Prokaryotic cells do not have a nucleus. Such cells are found in animals, like bacteria. Eukaryotic cells contain a nucleus and are found in the human body.

Cells can be divided into two types according to function.
1) Body cells and
2) Germ cells.

Body cells generally refer to somatic cells that make up most of the body’s tissues.

And germ cells produce functions associated with reproduction, such as sperm and eggs.

Cell structure:

Usually, a complete cell is formed by the nucleus, protoplasm, and cell wall. Apart from the nucleus, the other part of the cell is the protoplasm. The upper membrane of this protoplasm is called a cell wall. The fluid between the cell wall and the nucleus is called the cytoplasm.

1) Mitochondria: Mitochondria are called the powerhouse of the cell. They look small and long. Mitochondria help with cell nutrition and respiration.

2) Golgi Bodies: They are located near the nucleus and help in the secretion of the cell.

3) Cytoplasm is a complex colloidal substance, and in it, other structural elements of the cell are located.

4) The density of the centrosome is slightly higher than that of the cytoplasm. It accompanies the nucleus and helps in reproduction.

5) Cell wall: The entire cell is covered by this cell wall. The cell wall has numerous tiny pores, like a net.

6) Nucleus: This nucleus is the heart of the cell. The nucleus is covered by a membrane called a nuclear membrane. Inside the nucleus, there is a fluid called nuclear SAP.

Chemical components of cell:

Cells are usually made up of chemicals.

1) Protein: cells contain protein material.

2) Fat: contains oil or lipid-like substances.

3) Carbohydrates: sugars or carbohydrates are inside the cells.

4) Inorganic salts: Different types of inorganic salts, such as sodium, calcium, phosphate, chloride, etc., are inside the cells.

5) H2O: A part of the cell is made up of water. When the amount of water in the cells decreases, it is called dehydration. This dehydration can lead to death if it is severe. Because of this, it is often seen that people die of dehydration due to cholera or heat stroke.

Cell division:

The special process by which living cells divide into two or four (in the case of bacteria, cells are divided according to binary fission), and new cells are created is called cell division. The new cell that is formed by this cell division process is called the daughter cell. The original cell from which this division takes place is called the mother cell. Scientist Walter Fleming observed the first cell division in 1882 in the cells of the marine salamander (Triturus maculosa).

Cell Division

Types of cell division: 

Generally, three types of cell division are seen.
1) Mitosis cell division
2) Meiosis cell division.
3) Mitosis cell division.

What is mitosis cell division?

The process of cell division that produces two daughter cells from a single mother cell, and the newly created daughter cells have the same characteristics as the mother cell, is called mitosis cell division. In this process of cell division, the chromosome numbers of the mother cell and the daughter cell must be equal. Mitosis cell division is called equational cell division.

In the process of mitosis cell division, both the chromosomes and the nucleus divide only once. This is why the offspring cell has the same chromosome number as the mother cell. This cell division process normally occurs in body cells.

What is meiosis cell division?

The process of cell division that produces four daughter cells from a single mother cell, and the number of chromosomes in the daughter cell is half of the number of chromosomes in the mother cell, is called meiosis cell division. In the process of meiosis cell division, the chromosomes divide 1 time and the nucleus divides 2 times, hence, this process of cell division is called reductive cell division’.

What is amitosis cell division?

This type of cell division is commonly seen in bacteria and unicellular animals.

The process of cell division in which a mother cell divides directly without any complex and continuous process to form two daughter cells is called amitosis cell division. It is also called direct cell division. In this case, the nucleus and cytoplasm of the mother cell are divided directly. A groove is formed between the nucleus and the cytoplasm, and as this groove grows, the cell divides completely and divides into two new cells. Prokaryotic cells usually undergo this type of cell division. Cell division in amoeba takes place in the process of amitosis cell division.

Now we will discuss some more important questions and answers about cells.

What is the powerhouse of the cell?

Mitochondria is called the powerhouse of the cell. The energy production process of the cell is done by the mitochondria, which are called the powerhouse of the cell.

What is a cell wall?

The cell nucleus and protoplasm are both surrounded by a membrane. This coating is called a cell wall. This cell wall protects the nucleus and protoplasm.

What is nucleus?

The well-organized center of the cell is the nucleus. The brain of the cell is called the nucleus. Inside this nucleus, there is a kind of liquid called ‘nuclear SAP’. Inside the nucleus, there are also some thin thread-like substances called chromosomes. Within the chromatin network, the chromosome is a long DNA strand that contains the genetic material. The total number of chromosomes in human germ cells is 23 pairs. That is, a total of 46 chromosomes are present in each reproductive cell. Among these 23 pairs of chromosomes, one pair of chromosomes is the sex chromosome. They can be XX or XY. These sex chromosomes determine whether a child will be a boy or a girl.

What is prokaryotic cell?

The nucleus is the heart of the cell. However, in the case of some organisms, there are cells in which this nucleus is not well-organised. This type of cell is called a prokaryotic cell, such as a bacterial cell. In bacterial cells, the nuclear material is dispersed throughout the protoplasm in a floating state. Bacteria are called protocellular organisms because their nucleus are not well organised.

What is sclereids?

Sclereids are also known as ‘Stone Cells’ (the word sclereids comes from the Greek word meaning hard or hard). It is a type of specialized plant cell that is surrounded by a rigid and thick cell wall. These cells help to make the plant tough and strong. These types of cells have different shapes. Commonly, sclereids are found in the tissues of various fruits, nuts, and woody parts.

What is nerve cell?

A neuron is a special cell of the nervous system, which is the structural unit of the nervous system. It maintains communication between all nervous systems, and neurons play a direct role in sending and receiving various signals from one cell to another and in the brain. That is, the neuron is the basic unit of the nervous system that manages the communication and coordination of various functions of the body.

Finally, it can be said that although the cell is very small, its structure and its mechanism of action are very extensive, complex, and profound. It is necessary to study it patiently and thoroughly over and over again to understand it correctly.

Read More:
Septal deviation causes, treatment, and management

Dr. Dipankar Mondal.
Registered Homeopath.
04.02.2024

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