| A | B |
|---|
| meiosis | a form of cell division that halves the number of chromosomes. Used for sexual reproduction. |
| prophase I | chromosomes condense, homologous chromosomes pair up, crossing over occurs |
| metaphase I | pairs of homologous chromosomes are in the middle of the cell |
| anaphase I | homologous chromosomes separate. each chromosome is still composed of two chromatids |
| telophase I | individual chromosomes gather at the poles, cytoplasm divides |
| prophase II | a new spindle forms around the chromosomes |
| metaphase II | chromosomes line up at equator |
| anaphase II | sister chromatids separate and are pulled toward opposite poles of the cell |
| telophase II | nuclear envelope forms around each set of chromosomes, spindle breaks down, cytokinesis occurs, results in 4 different haploid cells |
| independent assortment | random distribution of chromosomes during meiosis |
| crossing over | portions of a chromatid on one homologous chromosome changes places with the corresponding portion on the other homologous chromosome |
| diploid | 2n |
| haploid | n |
| spermatogenesis | process by which sperm are produced in male animals |
| oogenesis | process by which gametes are produced in female animals |
| ovum | egg |
| polar body | small cell that is produced during oogenesis that does not become the egg |
| asexual reproduction | a single parent passes all th e copies of its genes to its offspring |
| clone | an individual produces by asexual reproduction, genetically identical to the parent |
| sexual reproduction | two haploid cells join to form genetically unique offspring |
| fertilization | joining of gametes |
| parthenogenesis | a type of asexual reproduction in which a new individual develops from an unfertilized egg |
| spore | haploid cell that can develope into an adult |
| sporophyte | diploid stucture that produces spores |
| gametophyte | haploid phase that produces gametes by mitosis |
