Describe cell in 100 words!
Answers
Many living beings are made up of only one cell: unicellular organisms, such as bacteria, arches and most protists. Others are made up of several cells: they are multicellular organisms, like plants and animals. The latter contain a very variable number of cells from one species to another; The human body thus counts on the order of one hundred thousand billion (1014), but is colonized by a number of one to ten-fold greater number of bacteria, which are part of its macrobiotic and are much smaller than human cells.
The existence of the cells was discovered in 1665 by the English naturalist Robert Hooke, who gave them the Latin name cellula in reference to the small rooms occupied by the monks in the monasteries. Cellular theory was formulated for the first time in 1839 by the German botanist Matthias Jakob Schneider and the German histologist Theodore Schwinn: it states that all living beings consist of one or more cells, that cells are the fundamental units Of all biological structures, that they always derive from other pre-existing cells, and that they contain the genetic information necessary for their functioning as well as the transmission of heredity to subsequent cell generations.
There large variety of organism on on this that are all distinct in their form and structure. However, they all possess similarity in their basic structure and functions . Just as building is made up of bricks, similarly , the 'bodies ' of all plants and animals are just made up of cells. From microscopic bacteria , or Amoeba , to large organism , like elephants, whales or gignatic trees , all are made up of cells the basic unit of all organisms. Some cells exist as 'UNICELLULAR OGANISM ' ( Single - celled individuals) while others are a part of multicellular organism. Certain functions like nutrition, respiration, Growth , development and reproduction , are performed by the cells in all organism. These functions are essential for the survival of the organisms. We , therefore , regard the cell as the basic structural as well as functional unit of all living organism . They remind undiscovered for a long time because the majority of cells are too small to be seen by unaided eyes. Robert who was the first scientist who in 1665 observed thin slices of cork obtained from the bark of a tree tharo is self design microscope he observed that they had honeycomb like structure consisting of cell compartments it was letter explain that these components your actually dead cells bounded by cell wall. aa cell consists of all living protoplasm surrounded by a cell membrane the protoplasm consists of cytoplasm and the nucleus cytoplasm contains a number of structure which are called cell organelles. Organelles' are there for structures present within a cell that help it to perform its relevant functions. The cell consists of the following parts :------- • Cell membrane • Nucleus • Cytoplasm
★ CELL MEMBRANE :-------
All living cells are bounded by a membrane called the plasma membrane or cell membrane. It energy like material called protoplasm. The plasma membrane controls the entry and exit of substance as per the requirement of the cell. The cells of plants, fungi , and bacteria have an additional outer covering called the cell wall. The cell wall is important covering in plant cells ; it provides rigidity and protection to the against variation in the environment. It also gives a definite shape, size and support to the cell.
★ CYTOPLASM :--------
The portion of the protoplasm lying inner to the cell membrane but outside the nuclear membrane is called protoplasm it acts as a ground substance for all cell activities it is made up of carbohydrate ,protein, fat and minerals and vitamins along with a large proportion of water all these components work together to provide a unique living nature to protoplasm.
★ NUCLEUS :---------
It is the most important part of the cell it generally lies in the centre of the cell however in some cases it may also occupy peripheral positions. It controls all the activities of the cell. The nucleus is a dense structure bound by a nuclear membrane. The protoplasm of the nucleus is called nucleoplasm. It has a thread like network called chromatin. When the cell is ready to divide this chromatin condenses to form ticket thread like structure called chromosomes. These chromosomes are the structures responsible for the characters inherited by one generation from the earlier generations. many small living organism are present in the cell. These are equivalent to the organs of the body hence they are named as 'cell organelles'.