Columbia Encyclopedia

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rorqual

(Encyclopedia)rorqual: see whale.

baleen

(Encyclopedia)baleen: see whale.

fertilization

(Encyclopedia)CE5 Fertilization of an egg cell fertilization, in biology, process in the reproduction of both plants and animals, involving the union of two unlike sex cells (gametes), the sperm and the ovum, f...

spermatozoon

(Encyclopedia)spermatozoon: see sperm.

infertility

(Encyclopedia)infertility, inability to conceive or carry a child to delivery. The term is usually limited to situations where the couple has had intercourse regularly for one year without using birth control. The ...

vasectomy

(Encyclopedia)vasectomy, male sterilization by surgical excision of the vas deferens, the thin duct that carries sperm cells from the testicles to the prostate and the penis. Vasectomy is a popular method of birth ...

ovum

(Encyclopedia)ovum ōˈvəm [key], in biology, specialized plant or animal sex cell, also called the egg, or egg cell. It is the female sex cell, or female gamete; the male gamete is the sperm. The study of the ovu...

James Bay Project

(Encyclopedia)James Bay Project, a colossal hydroelectric development of the rivers emptying into the E James Bay, central Quebec, Canada. La Grande Phase I, finished in 1985, created the world's largest undergroun...

beluga

(Encyclopedia)beluga bəlo͞oˈgə [key] or white whale, small, toothed northern whale, Delphinapterus leucas. The beluga may reach a length of 19 ft (5.8 m) and a weight of 4,400 lb (2,000 kg). It has a small, rou...

orca

(Encyclopedia)orca: see killer whale.