biol
81reduction division — Biol. 1. the first division of meiosis in which the number of chromosomes is reduced to half the original number. 2. meiosis. [1890 95] * * * …
82Schwann cell — Biol. a cell of the peripheral nervous system that wraps around a nerve fiber, jelly roll fashion, forming the myelin sheath. [1930 35; after T. SCHWANN, who first described it] * * * …
83sensory neuron — Biol. a nerve cell that conducts impulses from a sense organ to the central nervous system. * * * …
84sexual reproduction — Biol. reproduction involving the union of gametes. [1880 85] * * * …
85sexual selection — Biol. a special type of natural selection in which the sexes acquire distinct forms either because the members of one sex choose mates with particular features or because in the competition for mates among the members of one sex only those with… …
86Southern blot — Biol., Med. a procedure for identifying and measuring the amount of a specific DNA sequence or gene in a mixed extract, as in testing for a mutation or a virus: DNA strands from the person or organism under study are cut with restriction enzymes …
87sperm cell — Biol. 1. spermatozoon. 2. any male gamete. [1850 55] * * * …
88spontaneous generation — Biol. abiogenesis. [1650 60] * * * ▪ biology also called Abiogenesis, the hypothetical process by which living organisms develop from nonliving matter; also, the archaic theory that utilizes this process to explain the origin of life.… …
89squamous epithelium — Biol. epithelium consisting of one or more layers of scalelike cells. * * * …
90t.g. — Biol. type genus. * * * …
