BIO152H5 Lecture Notes - Lecture 5: Sister Chromatids, Chromatin, Chromosome
Document Summary
The ability of organisms to reproduce best distinguishes living things from nonliving matter. The continuity of life is based on the reproduction of cells, or cell division. Concept 12. 1: most cell division results in genetically identical daughter cells. Most cell division results in daughter cells with identical genetic information (dna) as the parent cell, and as each other. The exception is meiosis, a special type of division that produces sperm and egg cells. All the dna in cell constitutes its genome. A genome can consist of a single dna molecule (common in prokaryotic cells), or several dna molecules (common in eukaryotic cells) Every eukaryotic species has a characteristic number of chromosomes. In humans, somatic cells (non-reproductive cells) have two sets of chromosomes (2 x 23 = 46 total) Gametes (reproductive cells: sperm and eggs) have half as many chromosomes as somatic cells. During cell division, sister chromatids separate and move into two nuclei.
