Biology Chapter 12

Biology Chapter 12 - The Key roles of Cell Division - Cell...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
The Key roles of Cell Division - Cell Division: The reproduction of cells - Cell cycle: The life of a cell from the time it is first formed from a dividing parent cell until its own division I into two cells Cell division results in genetically identical daughter cells - Cell division involves the distribution of identical genetic material; DNA to two daughter cells Cellular Organization of the Genetic Material - Genome: cell’s genetic information - Before a cell divides, all the DNA is copied and the two copies separate so that each daughter cell ends up with a complete genome - Chromosomes: A threadlike, gene carrying structure, found in the nucleus, each chromosome consists of a long DNA molecule and associated proteins - Somatic Cell: Any cell in a multicellular organism except a sperm or egg cell - Each contain 46 chromosomes made up of two sets of 23, one set inherited from each parent - Gametes: reproductive cells - Sperm and egg cells, have half as many chromosomes as somatic cells ( one set of 23 chromosomes) - Chromatin: A complex of DNA and associated protein molecules Distribution of Chromosomes During Cell Division - After DNA duplication, the chromosomes condense - Each chromatin fiber becomes densely coiled and folded - Each duplicated chromosome has two sister chromatids - Chromatids contain an identical DNA molecule - In the condensed form it has a narrow waist, at a specialized region called the Centro mere where the two chromatids are most closely attached - Mitosis: The division of the nucleus followed by cytokinesis - The division of the cytoplasm - Gametes are produced by a variation of cell division called meiosis - Occurs in your gonads (ovaries or testes) - Yields no identical daughter cells in that only have one set of chromosomes - Half as many chromosomes as the parent cell Phases of the cell cycle - Mitotic (M) phase, includes both mitosis and cytokinesis - Shortest part of the cell cycle - Interphase: The period in the cell when the cell is not dividing, during interphase, cellular metabolic activity is high, chromosomes and organelles are duplicated, and size may increase. Interphase accounts for 90% of cell cycle, it can be divided into sub phases - G1 phase, S phase and G2 phase: the cell grows by producing proteins and cytoplasm
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/04/2010 for the course BIO 107 taught by Professor Abott during the Fall '09 term at UConn.

Page1 / 3

Biology Chapter 12 - The Key roles of Cell Division - Cell...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online