Cells And Organs

Cells
A cell is the basic unit of structure and function in a living thing. The human body contains about 100 trillion cells.
The cell is the basic structural andfunctional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The cellwas discovered by Robert Hooke in 1665.

Structures of Cells
The cell membrane forms the outside boundary of the cell. Inside the cell membrane is a large structurecalled the nucleus.

The nucleus is the center that directs the cells activities and contains the information that determines the cells form and structures.

Thematerial within a cell apart from the nucleus is called cytoplasm and is a jellylike substance.

Function
* Cells are capable of synthesizing new proteins, which areessential for the modulation and maintenance of cellular activities.
* Carry on processes that keep organisms alive.

Examples
Animal CellsPlant Cells
Organ
An organ is a structure that is composed of different kinds of tissue.An organ is a structure that contains at least two different types of tissue functioning together for a common purpose. Each organ of your body is part of an organ system. The maintissue is the one that is unique for the specific organ. Organs exist in all higher biological organisms, in particular they are not restricted to animals, but can alsobe identified in plants. In single-cell organisms like bacteria, the functional analogues of organs are called organelles.

Examples

Heart

Liver

Brain

Lungs