| A | B |
|---|
| anaphase | a phase of mitosis and meiosis in which the chromosomes separate |
| asexual reproduction | the production of offspring that does not involve the union of gametes |
| autosome | a chromosome that is not a sex chromosome |
| cell cycle | the events of cell divion,includes interphase, mitosis, and cytokinesis |
| centriole | a structure that appears during mitosis in animal cells (poles) |
| centromere | a region of the chromosome where the two sister chromatids are held together and which is the site of attachment of the chromosome to the spindle fibers during mitosis |
| chromatid | one of two identical parts of a chromosome |
| crossing-over | the exchange of genes by reciprical segments of homologous chromosomes during meiosis |
| cytokinesis | the division of the cytoplasm of one cell into two new cells |
| diploid | a cell that contains both chromosomes of a homologous pair |
| gamete | a reproductive cell- egg or sperm |
| genetic recombination | the new mixture of genetic material after crossing-over has taken place |
| haploid | having only one chromosome of each homologous pair |
| histone | a protein molecule that DNA wraps around during chromosome formation |
| homologous chromosome | one of a pair of morphologically similar chromosomes |
| interphase | a period of cell growth and development and DNA replication that precedes eukaryotic cell nuclear division |
| karyotype | a picture of an individual's chromosomes in a dividing cell |
| meiosis | the process of nuclear division that reduces the number of chromosomes in a cell by half |
| metaphase | the second phase of mitosis, during which all the chromosomes move to the cell's equator |
| mitosis | eukaryotic nuclear division |
| polar body | one of three small cells produced and discarded during each of the two meiotic divisions that yield the haploid egg cell |
| prophase | the first stage of mitosis and meiosis, chracterized by condensation of chromosomes |
| sex chromosome | a chromosome that determines sex, X or Y |
| sexual reproduction | the production of offspring from the combination of genetic material from two parent organisms |
| spindle fiber | one of the microtubles that extend across a dividing eukaryotic cell; assists in the movement of chromosomes |
| telophase | the final stage of mitosis during which a nuclear membrane forms around each set of new chromosomes |
| tetrad | a group of two homologous chromosomes during meiosis |
