Cells and different types of cells in the human body

Cells and different types of cells in the human body

Cells and different types of cells in the human body

Cells and different types of cells in the human body: The cell is the structural and functional unit of organisms, discovered by Robert Hooke in 1665 AD. Organisms with a single cell, such as bacteria, protozoa, and yeast, are called unicellular organisms and complex organisms with more than one cell are called multicellular organisms. All the organisms found on Earth can be divided into two classes:

  1. Acellular bio means organisms in which no cells are found, such as viruses.
  2. Cellular organisms mean organisms in which one or more cells are found.

Types of cells

Different types of cells in the human body. There are two types of cells depending on the composition. These are

  1. Prokaryotic cells and
  2. Eukaryotic cells.

Prokaryotic cells: These types of cells are called primitive cells. It is a cell with a simple structure. This type of cell lacks a clear nucleus. A bacterial cell is the best example of this type of cell. They usually range in size from 1μ to 10μ. The genetic material found in them, i.e., the chromosome produced by DNA, is present in a particular region of the cytoplasm. This particular region is called a nucleoid. Due to the absence of Nuclear membranes, substances found in the nucleus, such as DNA, RNA, proteins, etc. remain in contact with the cytoplasm. Ribosome particles are present in the cytoplasm, but there is a lack of other cells. In photosynthetic bacteria, the green chloride is present in the thalamic structure produced by the plasma membrane.

Characteristics of prokaryotic organisms

  • Undeveloped and primitive cells are found in these organisms.
  • They are small in size.
  • The nucleus is not found. Or rudimentary nucleus
  • The nucleus is also not found.
  • Only one chromosome is found.
  • Cells are also not found surrounded by cell walls.
  • Cell division occurs by incomplete division. Cyanobacteria such as bacteria and blue-green algae are examples of prokaryotic organisms.

Eukaryotic cells: The cells that are fully developed are called eukaryotic cells. These types of cells are found in all plants and animals except the virus, bacteria, and blue-green algae. It is a fully grown cell on an anatomical basis. They are large in size. This type of cell has a fully developed nucleus surrounded by double membranes. Membranous membranes are present in the cytoplasm. They have more than one number of chromosomes.

Characteristics of Eukaryotic Organisms

  • In these, developed and new cells are found
  • They are large in size
  • The nucleus is found.
  • A nucleus is also found.
  • More than one chromosome is found.
  • Cells are also found surrounded by cell walls.? Cell division occurs by mitosis and meiosis.

Difference between Prokaryotic cells and Eukaryotic cells

Prokaryotic cellsEukaryotic cells
In it, the cytoplasm is spread throughout the cell.The cytoplasm extends between the nucleus and the cell art.
Ribosomes are of the 70S type.There are both 70S and 80S types.
There is no vacuole.There is a vacuole.
Lysosomes are absent.Are present.
Respiration in these is done by the cytoplasm.Respiration is by mitochondria.
Cells such as galactic, endoplasmic reticulum, lavage, and mitochondria are absent in this cell.All cellulitis is present here.
The nucleus does not develop.Is fully developed.

Parts of cells.

The cell is mainly divided into two parts.

  1. Cell wall
  2. Protoplasm
  1. Cell Wall: The cell wall forms the outer covering of the cell, it is found only in the “plant cell”. It is made of cellulose. Whereas the outer membrane of an animal cell is called the “plasma membrane”. It is made up of lipoproteins.
  2. Protoplasm: Except for the cell wall of any cell, the rest is called protoplasm. These are the physical basis of life. Protoplasm is divided into two parts.
  1. Cytoplasm
  2. Nucleus


The part between the nucleus and the plasma membrane is called the cytoplasm. All the essential organs of the cell are found in this part, which is called the cell organ. Cell organ is as follows:

Endoplasmic reticulum: This is called the “skeletal system” of the cell. Its main function is to provide structural strength to the cell, which performs the function of protein synthesis.

Mitochondria: The cell’s powerhouse or energy house is called. Because it contains oxidation of food (only carbohydrates). Oxidation of food is called cellular respiration or inhalation. As a result of the oxidation of food, energy is stored in ATP form.


This is called the “direct and control” of the cell. The nucleus was discovered by Robert Brown. It is situated in the middle of the cell and controls all the functions of the cell. The nucleus is surrounded by a porous membrane called the center membrane. The nucleus has two parts:

  1. Nucleolus
  2. Neoplasm

D.N.A. And R.N.A. Are found in the nucleus.

Different elements found in the cell

  1. Oxygen – 65%
  2. Carbon – 18%
  3. Hydrogen – 10%
  4. Nitrogen – 2 • 5%
  5. Calcium – 0 • 15%
  6. Sodium – 2%

Cell Division 

The process of cell division was first reported to Virchau in 1855.

Cell division occurs in 3 ways:

Amitosis: Bacteria, indigo green algae, yeast, amoebae, and some protozoa, which have undeveloped cells, have “disarticulate division”.

Mitosis: Isotope division occurs only in somatic cells. In 1882 AD, this division of the cell by “water flaming” gave it the name of mitosis.

Meiosis: It is also called reduction division. The division was named by Farmer and Moore in Meiosis 1905. Meiosis occurs only in germ cells.

The main part of the cell

Mitochondria: The discovery was made in 1886 by Altman & Named-Benda. It is the respiratory place of cells.
Its number is uncertain. Its function is to provide energy to the human body by oxidizing energy-rich organic matter. Due to its functions, it is also called the powerhouse of the cell. Apart from the nucleus, DNA is also found in it.

Lysosome: The discovery was made by D. Duve, surrounded by microscopic, round, single membranes and contains 24 A enzymes whose functions are to feed and digest. It is also called the suicide sac of Kaushika. Lysosomes are absent in red blood cells (RBCs).