A cell represents everything a human is. If we think about all the functions our body’s perform, a cell does all of those. More than a hundred trillion cells make up the human body. They vary in size and shape and have different functions. Every cell has three features in common: The cell membrane, the nucleus and the cytoplasm. A cell, breathes, has food and liquid, reproduces, excretes, moves, does work and dies. One of the substances in the nucleus is DNA. This is the material that provides all the information about your genetic make-up that is I inherited from your parents and grandparents.
A tissue is an ensemble of similar cells from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues. An example is skin. Skin tissue is made up of lots of skin tissue. They work together to provide a protective covering for the internal organs of the body.
Organs are made up for different tissues that work together to carry out a particular function. An example is the liver; this organ plays a major role in metabolism and has a number of functions in the body, including glycogen storage, decomposition of red blood cells, plasma protein synthesis, hormone production, and detoxification
A system is made up of different tissues and organs, working together to perform a specific function in the body. The organs of the respiratory system include nose, trachea, and lungs. Many of the organ systems need to work together to help the body perform effectively.