Meaning : (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).
Synonyms : meiosis, reduction division
Meaning : Reflex contraction of the sphincter muscle of the iris in response to a bright light (or certain drugs) causing the pupil to become smaller.
Synonyms : light reflex, myosis, pupillary reflex