| A | B |
|---|
| autosome | chromosome not responsible for determining sex (22 pairs) |
| histone | protein that helps organize and pack DNA in the nucleus |
| chromatid | one of two identical copies of DNA in a chromosome that has replicated |
| centromere | the region of the chromosome where chromatids are held together |
| sex chromosome | a chromosome designated X or Y responsible for determining the sex of an organism |
| homologous chromosomes | a pair of chromosomes of the same size, shape, and carrying genes for the same trait |
| karyotype | a photograph of the chromosomes of an individual arranged in homologous pairs |
| diploid | 2n, two sets of choromosomes found in somatic cells |
| haploid | 1n, one set of chromosomes in anucleus of a gamete |
| gamete | sex cell, either a sperm or egg |
| binary fission | nucleoid and cell division in a prokaryote |
| mitosis | a stage of the cell cycle that divides the nucleus into two identical nuclei |
| meiosis | nuclear division that divides the nucleus to make cells with 1n chromosomes |
| cytokinesis | division of the cytoplasm of a cell |
| gap 1 phase | G1 of interphase, cells grow and metabolize |
| gap 2 phase | G2 of interphase, cells prepare for nuclear division |
| S phase | S of interphase, DNA replicates |
| G0 phase | cells exit from the cell cycle, no further cell division |
| prophase | chromosomes form, nuclear membrane breaks down |
| metaphase | chromosomes are at the cell equator |
| anaphase | chromatids separate and move toward cell poles |
| telophase | chromosomes uncoil, nuclear membrane reforms |
| spindle fibers | microtubules organized by the centriole responsible for dividing the chromatids |
| kinetochore fibers | spindle fibers attached to the chromosome |
| polar fibers | spindle fibers that reach from centriole to centriole to lengthen the cell |
| cleavage furrow | where the animal cell pinches in two to make two cells at cytokinesis |
| cell plate | a cell wall that forms between the divided nuclei to form two plant cells at cytokinesis |
| synapsis | when two homologous chromosomes pair during meiosis P1 |
| tetrad | the pair of homologous chromosomes formed at P1 |
| crossing-over | the exchange of a portion of the chromatids of homologous chromosomes in P1 |
| independent assortment | reandom separation of homologous chromosomes in A1 |
| polar bodies | nuclear products of oogenesis that degenerate and do not become an egg |
| spermatogenesis | formation of sprem cells through meiosis |
| oogenesis | formation of egg cells through meiosis |
| sexual reproduction | when two gametes fuse to form a 2n organism |
| asexual reproduction | reproduction that does not involve gametes, but is the result of mitosis or binary fission |
