| A | B |
|---|
| Germ Cells | Animal cell of a lineage set aside for sexual reproduction; gives rise to gametes |
| gametes | Haploid cell, formed by meitotic cell division of a germ cell; required for sexual reproduction |
| asexual reproduction | Any of a number of modes of reproduction by which offspring arise from a single parents and inherit the genes of that parent only |
| genes | Unit of information about a heritable trait, passed from parents to offspring. |
| sexual reproduction | Production of offspring by meiosis, gamete formation, and fertilization |
| allele | For a given gene locus, one of 2 or more slightly different molecular forms of a gene that arise through mutation and that code for different versions of the same trait |
| meiosis | 2-stage nuclear division process that halves the chromosome # of a parental germ cell |
| chromosome number | All chromosomes in a given type of cell. |
| homologous chromosomes | Of cells w/ a diploid chromosome #, one of a pair of chromosomes that are idnetical in size, shape, and gene sequence, and that interact at meiosis |
| Sister chromatids | Of a duplicated chromosome, 1 of 2 DNA molecules attached at the centromere until the are separated from each other during mitosis or meiosis |
| Crossing over | At prophase I of m eiosis, an interaction in which nonsister chromatids break at corresponding sites and exchange segments; genetic recombination is the result |
| spores | Reproductive or resting structure of one or a few cells, often walled or coated and adapted for resisting adverse conditions, for dispersal, or both |
| Sperm | Mature male gamete |
| oocyte | Immature egg of all animals and some protistans |
| fertilization | The fusion of a sperm nucleus with the nucleusof an egg, which thus becomes a zygote |
| diploidy | Presence of 2 of each type of chromosome in a cell nucleus at interphase |
| haploidy | Presence of only half of the parental number of chromosomes in a spore or gamete, as brought about by meiosis |
