cell biology | what is cell biology | Who discovered cell biology | cell biology in english

Today we will tell you about cell biology

Robert Hooke discovered the dead cell

Leuven Hooke discovered the living cell


What are cells?
 Cellular organisms are capable of
 (1) independent existence and 
(2) all the essential functions of life.

 Without a cell, no independent organism can exist. For this reason, the cell itself is the basic structural and functional unit for an organism.

 Antonvan Leuwenhoek first observed and described the cell. Robert Brown later discovered the nucleus. After the discovery and later improvement of microscopes, it became possible to study the detailed structure of the cell by phase-contrast and electron microscopes.

 cell theory, cell biology

 In 1838, German botanist Matthias Schleiden, after studying many plants, found that these plants consist of different types of cells, which form tissues in plants. Around the same time in 1839, a British zoologist Theodor Schwann, after studying various animal cells, found that a thin layer is found outside the cells, which is today called 'protoplasm'. This scientist, after studying plant tissues, found that cell wall is found in plant cells which is its specialty. On the basis of the above, Schwan while keeping his hypothesis said that the body of animals and plants is made up of cells and their products.


 Schiden and Schwann jointly propounded the cell theory. However, his theory failed to explain how new cells are formed. For the first time, Rudolf Bich (1855) explained that the cell divides and new cells are formed by the division of pre-existing cells (omnis cellul-e cellula). He propounded the new cell theory by transforming the imagination of Sliden and Schwann. The cell theory in the present day perspective is as follows:

 All organisms are made up of cells and cell products.
 All cells are made up of pre-located cells.


 overall overview of the cell , cell biology

 In the beginning you may have observed onion peel and/or human cheek cells under a microscope. Remember their structure. The onion cell, which is a typical plant cell, has a clear cell wall on its outer surface and a cell membrane just below it. In the organization of the human cheek cell, only one membrane structure is visible on the outside. Inside each cell is a densely membranous structure called the nucleus. This nucleus contains the chromosome, which contains the genetic material DNA. A cell that has a membrane-bound nucleus is called a eukaryote and a cell that does not have a membrane-bound nucleus is called a prokaryote. Both eukaryotic and prokaryotic cells have a semi-liquid matrix surrounding its volume called cytoplasm. The cytoplasm is a major site for cellular activities in both plant and animal cells. Various chemical reactions related to the 'living stage' of the cell take place here.

 In eukaryotic cell, apart from the nucleus, there are various other membrane-bound structures, which are called organelles such as endoplasmic reticulum (endoplasmic reticulum), formula granules (mitochondria), microbodies (microbodies), Golgi complex, lysosomes and vacuoles Absence of membranous cells in prokaryotic cells it happens.

 In both eukaryotic and prokaryotic cells, membraneless organelles ribosomes are found. Within the cell, ribosomes are found not only in the cytoplasm, but also in two organelles – chloroplasts (in plants) and granules and rough endoplasmic reticulum.

 Animal cells contain other organelles such as membraneless stellate nuclei, which help in cell division.

 Cells vary greatly in size, shape and function (Figure 8.1). For example, the smallest cell mycoplasma is 0.3um (micrometer) in length, while bacteria are 3 to 5um (micrometer). The largest cell separated is similar to that of an ostrich egg. The diameter of a human red blood cell in multicellular organisms is about 7.0um (micrometers). Nerve cells are among the longest cells. They may be rectangular, polygonal, erect, cuboidal, thread-like or asymmetrical type. The form of cells may vary according to their function. 

Cell biology
What is cell biology



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