Biology

The human cell is said to be a living thing because it is a basic functional unit of any living organism. Thus it performs the most detailed functions like energy generation, facilitating tissues functions, hence organism control. Body cells feed, grow, respire, excrete and can die.

A cell is the smallest basic unit of life. It is made up of chemical substances such as atoms, ions and molecules that are important for life. The body is made up of different types on cell. For instance, egg cell, muscle cell, rode cells found in the eye, sperm cell, hair cell and nerve cell. Each of these different types of cell performs different functions in the body of the organism. Different cells are joined together through biological processes to form tissues, for example, epithelia tissue and muscles tissue. More so, different tissues unite to form different organs.  An organ is formed of two or more tissues that collectively undertake a specific function in the body of an organism. Some examples of organs are the stomach, heart, kidney, lungs, and liver.

When a number of organs are coordinated together towards a certain body function they form a system. The human body has eleven major systems which include the digestive, respiratory, nervous, circulatory, lymphatic, skeletal, endocrine, reproductive, integumentary, muscular and urinary systems.
As discussed earlier the livelihood of an organism depends entirely on the functionality of each particular cell, tissue, organ and system. For example, the reproductive system is responsible for the propagation of genetic material to new organisms of the same species. The system results from the organization of reproductive cells, tissues and organs. In other wards, if each particular cell, tissue, organ and system functions effectively within its role the organism must be sustained alive. All the body systems are interlinked to form a fully functioning organism

It is worth noting that for any cell or tissue and body part to function effectively it must be supplied with enough energy. The process by which energy is made available to cells and organs is metabolism. This process ensures an endless flow of matter and energy via an interlinked set of connections of chemical reactions within the cell, tissues, organs and organ systems. This results in a sustainable and continuous supply of body building materials, constant body repair and development of the organism. Generally, biological life is maintained by metabolism which involves food intake, digestion and its subsequent transformation into energy source for the cells. Food plays a vital role in the growth and development of body cells hence organisms health and life satiability. All living thing feed, grow, reproduce, move, breath and die. Food intake necessitates growth, development, reproduction, breathing, digestion, excretion, movement of organisms.  

Organisms are categorized in to five kingdoms animals, plants, fungi, protisti and bacteria. The fetal pig and human are related in their body systems since they are all animals. They are further classed in to mammals which bring them closer in terms of organ systems such as respiration, digestion, reproduction and endocrine systems. Thus when a fatal pig grows, its body functions the same as that of and adult pig except for a few systems. The development processes involved in pigs is similar to that of humans.

In conclusion, body systems are formed by organs, which are formed by tissues resulting from cells. A living organism sustains its life and health through internetworking of the different body organs and systems through their specific functions in the body. The cell is a basic unit of life.