| A | B |
| Histones | a group of special protein molecules |
| Chromatid | each part of the two identical parts in a chromosome |
| Centromere | the point where each pair of chromatid is attached |
| Homologous chromosomes | the two members of each pair in a chromosome |
| Diploid | a cell that contains both chromosomes of a homologous pair |
| Haploid | a cell that only has one chromosome of each homologous pair |
| Mitosis | the division of the cell nucleus in which chromosomes in the parent cell divide into two identical sets |
| Cell cycle | the sequence of events that occurs in a cell from mitosis to mitosis |
| Interphase | a period of cell growth and development that precedes mitosis and follows cytokinesis |
| Cytokinesis | the division of the cytoplasm of a parent cell and its contents into two daughter cells |
| G1 phase | the first period in interphase |
| S phase | the phase where DNA makes up the chromatin replicates |
| G2 phase | the cell undergoes rapid growth that prepares it for mitosis |
| Prophase | the first phase of mitosis |
| Centrioles | small, dark. cylindrical bodies |
| Polar fibers | a type of spindle fiber that extends across the cell from centriole to centriole |
| Kinetochore fibers | a fiber extending from a centriole to a centromere during mitosis |
| Asters | protein fibers that radiate from each centriole |
| Metaphase | the second phase of mitosis |
| Anaphase | the third phase of mitosis |
| Telophase | the final phase in mitosis |
| Cell plate | a membrane across the middle of the cell |
| Meiosis | the process of nuclear division that reduces the number of chromosomes by half |
| Meiosis I | the first division |
| Meiosis II | the second division |
| Synapsis | the pairing of homologous chromosomes |
| Tetrad | a group of two chromosomes |
| Crossing-over | the exchange of genes by homologous chromosomes during meiosis |
| Gametes | sexual reproductive cells |
| Ootid | the egg cell |
| Polar bodies | The other three cells formed during meiosis I and meiosis II |
| Asexual reproduction | the production of offspring from one parent without the union of gametes |
| Sexual reproduction | the production of offspring through meiosis and subsequent fusion of gametes |
| Genetic recombination | the process that results in chromosomes being rearranged in many different ways |