life cycle

See synonyms for life cycle on
  1. Biology. the continuous sequence of changes undergone by an organism from one primary form, as a gamete, to the development of the same form again.

  2. a series of stages, as childhood and middle age, that characterize the course of existence of an individual, group, or culture.

  1. any similar series of stages: the life cycle of a manufactured product.

Origin of life cycle

First recorded in 1870–75

Words Nearby life cycle Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use life cycle in a sentence

British Dictionary definitions for life cycle

life cycle

  1. the series of changes occurring in an animal or plant between one development stage and the identical stage in the next generation

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for life cycle

life cycle

  1. The series of changes in the growth and development of an organism from its beginning as an independent life form to its mature state in which offspring are produced. In simple organisms, such as bacteria, the life cycle begins when an organism is produced by fission and ends when that organism in turn divides into two new ones. In organisms that reproduce sexually, the life cycle may be thought of as beginning with the fusion of reproductive cells to form a new organism. The cycle ends when that organism produces its own reproductive cells, which then begin the cycle again by undergoing fusion with other reproductive cells. The life cycles of plants, algae, and many protists often involve an alternation between a generation of organisms that reproduces sexually and another that reproduces asexually. See more at alternation of generations.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.