Definition

A cell is defined as the functional and structural units of all living things. Essential genetic information can be found in these cells, and this information is used in the reproduction process.

Types

There are two basic cell types within living organisms. The first is unicellular, consisting of a single cell. Bacteria are examples of unicellular organisms. Humans are classified as multicellular, having many cells.

Fun Fact

According to the National Center for Biotechnology Information, humans have as many as 100 trillion cells. All of these cells are reproduced from pre-existing cells.

Categories

There also are two general cell categories used to classify living organisms. The first is known as prokaryotic. This category includes organisms such bacteria and all others lacking nuclear membranes. Eukaryotic organisms fall into the second cell category. The presence of a nucleus is what makes eukaryotic organisms different from prokaryotic.

Basic Cell Components

1. Plasma membrane: outer protective lining of a cell. 2. Cytoskeleton: maintains the cell's shape. 3. Cytoplasm: large, fluid-filled space where mechanics of the cell take place. 4. Organelles: tiny organs that carry out vital cell functions. 5. Cucleus: the cell's center.

Source:

NCBI