| A | B |
|---|
| cell cycle | All events that occur in a cell from the time it divides to the time it divides again |
| interphase | most cells are in this stage of the cell cycle when growth, replication of DNA, preparation for division occurs |
| prophase | chromosomes become visible as the nuclear membrane breaks down |
| metaphase | replicated chromosomes line up at the "equator"of the cell |
| anaphase | sister chromatids of the replicated chromosomes split and head for the "poles" |
| chromatids (sister) | identical chromosomes attached to each other by a centromere |
| centromere | the protein "glue wad" that holds sister chromatids together |
| spindle fibers | fibers of microfilaments that contract and split the chromotids |
| G1 phase | interphase time of cell growth and replication of organelles |
| S phase | interphase time of DNA replication |
| G2 phase | interphase time of preparation for cell division by checking for DNA mistakes |
| cytokinesis | division of the cell cytoplasm into 2 cells |
| chromosome | a "package" of 4,000 - 5,000 genes (humans have 23 kinds) |
| mitosis | cell division process that divides the nucleus |
| telophase | last stage of mitosis when the nucleus reforms and cytokinesis occurs |
| chromatin | unwound DNA in the nucleus during interphase |
| replicated chromosome | a chromosome made of 2 identical chromatids |
| homologous chromosomes | chromosomes with the same kinds of genes on them |
| diploid | twice the number (2n) of chromosomes (46 in humans) |
| haploid | half the diploid number of chromosomes (n=23 in humans) |
| meiosis | cell division process in gametes (sperm & eggs) |
| meiosis 1 | 1st division of meiosis resulting in 2 cells (haploid) |
| meiosis 2 | 2nd division process in meiosis resulting in 4 haploid cells |
| independent assortment | the occurrence of 1 trait has nothing to do with another trait if on different chromosomes |
| gene map | a diagram of where genes occur on chromosomes |
