Cell The cell (Latin word means 'little room') is the basic structural, functional and biological unit of all known living organisms. Cells may be compared to the bricks which are assembled to make a building. Cells are also assembled to make the body of every organism.
Cell Cycle and Cell Division All organisms start their life from a single cell and grow by the addition of new cells. The new cells arise by the division of pre-existing cells. This idea was suggested by Rudolf Virchow in 1858 in a particular statement 'Omnis Cellula e Cellula', means 'every cell produces from a cell. This states that the continuity of life depends on cell reproduction or cell division.
Genetics Genetics is a branch of biology that deals with inheritance as well as variation of characters from parents to offsprings. The term genetics was firstly used by W Bateson in 1905. Inheritance is the process by which characters are passed on from parents to progeny and is the basis of heredity. It is due to heredity that, the born offsprings resemble their parents. All organisms such as human beings, plants or animals, exhibit various characteristics. Each character is carried forward to offsprings by the genes ( core component of chromosomes). Variation is the degree by which progeny differ from their parents.
Tissue The term tissue was coined by N Grew. It is defined as a group of cells that are structurally similar and constitute together to perform a particular function.i e.g., blood, phloem, muscle, etc. Tissues are broadly categorised into plant tissues and animal tissues. Branch of biology which deals with the study of tissues is known as histology.
Human Nervous System Nervous system is fully restricted to animals and not found in plants. It is mainly ectodermal in origin and functions in an integrated manner for control and coordination of various body functions (responding, understanding and memorising) through neurons and hence also called as neural system.
Human Circulatory System ::- The system, which is primarily meant for the circulation of nutritive products, disposal and excretion of waste material in the body is know as circulatory system. The two basic types of circulatory system have evolved in animals such as
Reproduction ::- Reproduction is a biological process in which an organism give rise to young ones (offsprings). There is a continous cycle of birth, growth and death.
Human Respiratory System All organisms use respiration as a beneficial process for release of energy. It is basically an oxidation process of food substances within the tissues to form CO2, and water with consequent release of energy. The energy produced is stored in the form of ATP (Adenosine Triphosphate, energy currency of cell) and CO2 and water are considered as the byproduct of this respiration process.
Human Digestive System ::- Biomacromolecules which we consume in our food are not directly utilised by our body in its original form. Thus, they are subjected to a process called digestion and the system that helps in complete process of digestion by mechanical and biochemical methods is called digestive system. The human digestive system consists of various parts (organs and glands) that are concerned with the uptake, digestion and elimination of indigestible remains of food from the body. Human alimentary canal and its associated glands are shown in the figure below
Human Skeletal System Skeletal system is the framework of bones and cartilages that protect our organs and allow us to move. This system includes all of the bones and joints in the body.
