| A | B |
|---|
| gametes | sex cells |
| fertilization | fusion of the nuclei of male and female gametes |
| zygote | a single cell formed from the fusion of gametes |
| meiosis | cell division that results in gametes with half the number of chromosomes as the parent cell |
| somatic cells | body cells |
| homologous chromosomes | chromosomes similar in size and shape and have similar genetic content |
| diploid | homologous chromosomes characteristic to the species; 2n |
| haploid | half the number of chromosomes; n |
| daughter cells | cells that arise from a parent cell |
| tetrad | four chromosomes |
| disjunction | homologous chromosomes from each tetrad separate and move to opposite poles |
| gonads | specialized organs where gametes develop |
| ovaries | female gonads |
| testes | male gonads |
| ova | female gametes, or eggs |
| sperm cells | male gametes |
| hermaphrodites | animals which have both testes and ovaries |
| gametogenesis | process by which gametes develop in the gonads |
| oogenesis | formation of eggs in the ovaries |
| spermatogenesis | formation of sperm in the testes |
| oogonia | immature egg cells |
| follicle | small, spherical sac in which the egg develops |
| ootid | maturing egg cell |
| spermatogonia | immature sperm cells |
| acrosome | part of sperm that contains enzymes to penetrate the egg |
| middle piece | part of sperm cell packed with mitochondria |
| external fertilization | gametes fuse outside the female's body |
| internal fertilization | gametes fuse inside the female's body |
