Definition: Gravel is an environmental material which is composed of pieces of rock that are at least two millimeters (2mm) in its largest dimension and no more than 75 millimeters.
Definition: Solitary animals are those that spend a majority of their lives without others of their species, with possible exceptions for mating and raising their young. Antonyms for a solitary animal include a social animal or a colonial animal.
Definition: The second nuclear division of meiosis, in which the two chromatids in each chromosome are separated, resulting in four daughter nuclei from the two nuclei produced in meiosis I
