Write an Article on cell
Answers
Answer:
Anything less than a complete cell cans neither lead an independent existence nor perform all the functions of life. A multicellular organism is made of many cells. A higher animal or plant contains billions of cells. For example, a newly born human infant has 2 x 1012 cells.
The number increases to 100 trillion (100 x 1012 or 1014) cells in the body of 60 kg human being. About 25% (25 x 1012) of them are found in the blood. A drop of blood contains several million cells. The large sized organisms do not have large sized cells. Instead they possess higher number of cells. In multicellular organisms, cells are building blocks of the body or basic units of body structure.
Of course, they become specialized for performing different functions. Human body has some 200 types of cells, e.g., erythrocytes, leucocyte types, epithelial cell types, muscle cells, nerve cells, fat cells, cartilage cells, bone cells, connective tissue cells, gland cells, germinal cells, pigment cells, etc.
Cells are grouped into tissues, tissues into organs and organs into organ systems. Occurrence of different types of tissues, organs and organ system results in division of labour or performance of different functions of the body by specialised structures.
Cells are not only the building blocks of the organisms, they are also the functional units of life. Life passes from one generation to the next in the form of cells.
The activities of an organism are actually the sum total of activities of its cells. Each cell of the body possesses the same genetic information though mature cells may become specialized to perform specific functions. A new cell always develops by division of a pre-existing cell.
Cells are totipotent, i.e., a single cell has the ability to form the whole organism. Internally each cell is build up of several organelles. The organelles perform different functions just like the ones carried on by different organ systems of the body.
All life activities of the organism are present in miniature form in each and every cell of its body. Thus, cell is a basic unit of life and structural and functional unit of an organism. It is the smallest unit capable of independent existence and performing the essential functions of life.
Answer:
please mark the one above the brainliest