life cycle

American  

noun

• life cycles
  plural

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.

3. any similar series of stages.

   the life cycle of a manufactured product.

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life cycle British  

noun

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

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life cycle Scientific  

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.

2. See more at alternation of generations

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Other Word Forms

Noun Inflected Forms

• life cycles
  plural

Etymology

Origin of life cycle

First recorded in 1870–75

Example Sentences

See Examples For:

life cycle

That’s why it affects mainly produce that has a longer life cycle from crop cultivation and irrigation to when it hits store shelves and is consumed.

From The Wall Street Journal ● Jul. 17, 2026

As cells reach the end of their life cycle and begin to self-destruct, they undergo a series of physical changes.

From Science Daily ● Jun. 24, 2026

Their hydropower plants, which have a long life cycle and generate high free cash flow, are underappreciated by the market, they write.

From The Wall Street Journal ● Jun. 22, 2026

But Green, who oversaw that recovery project, said the bog bush cricket would be more difficult to rear because it can be cannibalistic and has a longer, two-year life cycle.

From BBC ● Jun. 15, 2026

The spiders were carrying on their life cycle at the back of Kitum Cave.

From "The Hot Zone" by Richard Preston

Related Words

• biological clock