Walrus pups are able to swim at birth and weigh between 100 and 150 pounds. Most are only children (twin births are rare), and they stay with their mothers for two years. Eventually, their small young tusks will grow up to three feet long.
Definition of nuclear for Students. 1  1 : of, relating to, or being a nucleus (as of a cell) 2  2 : of or relating to the nucleus of the atom Fission is a nuclear reaction. 3  3 : produced by a nuclear reaction nuclear energy.  4 : of, relating to, or being a weapon whose destructive power comes from an uncontrolled nuclear reaction.
Nucleus. Definition. noun, plural: nuclei. (general) The core or the central part around which other parts are grouped or gathered. (biology) The large, membrane-bounded organelle that contains the genetic material, in the form of multiple linear DNA molecules organized into structures called chromosomes.upplement. In biology, the major functions of nucleus are to maintain the integrity of DNA and to control cellular activities such as metabolism, growth, and reproduction by regulating gene expression. It has three main components: the nucleolus, the chromatin and the nuclear envelope.