Cellls+and+Tissues+DB



1. A cell is the basic unit of life. Most cells can only be seen under a microscope. 2. The cell theory states that the cell is the basic unit of life, all living things are made up of cells, and that new cells arise from preexisting cells. 3. Cells are tiny so that they are able to have a large surface area to move materials in and out of the cell. A small cell will produce a small amount of waste and only require a small amount of nutrients to function.

4. A eukaryotic cell has a plasma membrane, a nucleus, and a cytoplasm. 5. A prokaryote has a plasma membrane and a cytoplasm, but lacks a nucleus. 6. The eukaryotic cell may have evolved to have a nucleus due to an pocket forming in the plasma membrane. During the process, a endomembrane system was established. The mitochondrian and chloroplast of enkaryotic cells may have come about after one cell engulfed a prokaryote.

7. A tissue is a group of specialized cells in the body that work together to perform the same task. 8. Connective tissues in the body provide organs with protective covering and support parts of the body such as cartilage and bone. Muscular tissue moves the muscles in the body. When it contracts, a body part is moved. Nervous tissue is in charge of communication between parts of the body, including sensory input, integration of data and motor output. Finally, epithelial tissue may control excretion, absorption, secretion and filtration in the body, but it also lines areas and covers body surfaces.