reflex contraction of the sphincter muscle of the iris in response to a bright light (or certain drugs) causing the pupil to become smaller | the act of segregating or sequestering |
(genetics) cell division that produces reproductive cells in sexually reproducing organisms; the nucleus divides into four nuclei each containing half the chromosome number (leading to gametes in animals and spores in plants) | a social system that provides separate facilities for minority groups |
| (genetics) the separation of paired alleles during meiosis so that members of each pair of alleles appear in different gametes |