Cell
Cell: The basic structural and functional unit of any living thing. Each cell is a small container of chemicals and water wrapped in a membrane. There are 100 trillion cells in a human, and each contains all of the genetic information necessary to manufacture a human being. This information is encoded within the cell nucleus in 6 billion subunits of DNA called base pairs. These base pairs are packaged in 23 pairs of chromosomes, with 1 chromosome in each pair coming from each parent. Each of the 46 human chromosomes contains the DNA for thousands of individual genes.
Read Also:
- Celiac sprue
Celiac sprue: An immune disorder whereby the small intestine is injured when exposed to gluten, a protein found in wheat and related grains. Celiac sprue causes impaired absorption and digestion of nutrients through the small intestine. Symptoms include frequent diarrhea and weight loss. A skin condition called dermatitis herpetiformis is sometimes associated. The most accurate […]
- Cell cloning
Cell cloning: The process of producing a group of cells that are genetically identical (clones) to a single ancestral cell.
- Cell cycle
Cell cycle: The sequence of events within the cell between mitotic (cell) divisions. The cell cycle is conventionally divided into five phases: G0 (the gap); G1, (the first gap); S (the synthesis phase, during which the DNA is synthesized and replicated); G2 (the second gap); and M (mitosis). Cells that are not destined to divide […]
- Cell fusion
Cell fusion: The melding of two or more cells into one cell called a heterokaryon. A heterokaryon may reproduce itself for at least several generations. Cell fusion provides a method for assigning specific genes to specific chromosomes. When an undifferentiated stem cell fuses with a mature differentiated cell, the resultant cell can retain the mature […]
- Cell lineage
Cell lineage: A genealogic pedigree of cells related through mitotic division.