Life cycle of a mosquito. An adult female mosquito lays eggs which develop through several stages to adulthood. Reproduction completes and perpetuates the cycle.
In biology, a biological life cycle (or just life cycle when the biological context is clear) is a series of stages of the life of an organism, that begins as a zygote, often in an egg, and concludes as an adult that reproduces, producing an offspring in the form of a new zygote which then itself goes through the same series of stages, the process repeating in a cyclic fashion.
"The concept is closely related to those of the life history, development and ontogeny, but differs from them in stressing renewal."[1][2] Transitions of form may involve growth, asexual reproduction, or sexual reproduction.
In some organisms, different "generations" of the species succeed each other during the life cycle. For plants and many algae, there are two multicellular stages, and the life cycle is referred to as alternation of generations. The term life history is often used, particularly for organisms such as the red algae which have three multicellular stages (or more), rather than two.[3]
Life cycles that include sexual reproduction involve alternating haploid (n) and diploid (2n) stages, i.e., a change of ploidy is involved. To return from a diploid stage to a haploid stage, meiosis must occur. In regard to changes of ploidy, there are three types of cycles:
haplontic life cycle — the haploid stage is multicellular and the diploid stage is a single cell, meiosis is "zygotic".
diplontic life cycle — the diploid stage is multicellular and haploid gametes are formed, meiosis is "gametic".
haplodiplontic life cycle (also referred to as diplohaplontic, diplobiontic, or dibiontic life cycle) — multicellular diploid and haploid stages occur, meiosis is "sporic".
The cycles differ in when mitosis (growth) occurs. Zygotic meiosis and gametic meiosis have one mitotic stage: mitosis occurs during the n phase in zygotic meiosis and during the 2n phase in gametic meiosis. Therefore, zygotic and gametic meiosis are collectively termed "haplobiontic" (single mitotic phase, not to be confused with haplontic). Sporic meiosis, on the other hand, has mitosis in two stages, both the diploid and haploid stages, termed "diplobiontic" (not to be confused with diplontic).[citation needed]
^Bell, Graham; Koufopanou, Vassiliki (1991). "The Architecture of the Life Cycle in Small Organisms". Philosophical Transactions: Biological Sciences. 332 (1262): 81–89. Bibcode:1991RSPTB.332...81B. doi:10.1098/rstb.1991.0035. JSTOR 55494.
^Cite error: The named reference rodr2014 was invoked but never defined (see the help page).
^Dixon, P.S. 1973. Biology of the Rhodophyta. Oliver & Boyd. ISBN 0 05 002485 X[page needed]
and 26 Related for: Biological life cycle information
In biology, a biologicallifecycle (or just lifecycle when the biological context is clear) is a series of stages of the life of an organism, that begins...
opposed to a randomized occurrence of events. The relevance of a biologicallifecycle relating to the growth of an organization, was discovered by organizational...
generally in a temperate climate, takes two years to complete its biologicallifecycle. In its first year, the biennial plant undergoes primary growth...
differentiation to form mature haploid gametes. Depending on the biologicallifecycle of the organism, gametogenesis occurs by meiotic division of diploid...
is associated with a fungus, which is the true saprophyte. Its whole lifecycle, and especially its reproduction, is still mostly unknown. Thismia rodwayi...
adults. This breaks the biologicallifecycle of the insect, preventing recurring infestation. Methoprene is considered a biological pesticide because rather...
extensively to the development of biological knowledge. He explored biological causation and the diversity of life. His successor, Theophrastus, began...
A tadpole is the larval stage in the biologicallifecycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles...
biogeochemical redox reactions within the cycle. Processes within the oxygen cycle are considered to be biological or geological and are evaluated as either...
Other major biogeochemical cycles include the nitrogen cycle and the water cycle. Carbon is the main component of biological compounds as well as a major...
The biological pump (or ocean carbon biological pump or marine biological carbon pump) is the ocean's biologically driven sequestration of carbon from...
multicellular organisms have two sets of chromosomes at some point in their biologicallifecycle; that is, they are diploid. In this case, the chromosomes can be...
A lifecycle ritual is a ceremony to mark a change in a person's biological or social status at various phases throughout life. Such practices are found...
Biological rhythms are repetitive biological processes. Some types of biological rhythms have been described as biological clocks. They can range in frequency...
nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification...
than from sunlight. The process of biological carbon fixation plays a crucial role in the global carbon cycle, as it serves as the primary mechanism...
its lifecycle within one growing season and then dies Biennial plant – Flowering plant that takes two years to complete its biologicallifecycle Herbaceous...
the environment by providing secretory and absorptive functions. The lifecycle of a typical trematode begins with an egg. Some trematode eggs hatch directly...
An annual plant is a plant that completes its lifecycle, from germination to the production of seeds, within one growing season, and then dies. Globally...
parasites, have lifecycle stages that allow them to survive the wide variety of environments they are exposed to during their complex lifecycle. Each stage...
Phenology is the study of periodic events in biologicallifecycles and how these are influenced by seasonal and interannual variations in climate, as...
in sexual selection, fecundity is contrasted to reproductivity. Biologicallifecycle Birth rate Fecundity selection Natalism Population ecology Etienne...
Conway's Game of Life, works of Polish painter Zdzisław Beksiński, and Koyaanisqatsi. Some features, such as the biologicallifecycle of the tribespeople...
Product lifecycle management (PLM) should be distinguished from 'product life-cycle management (marketing)' (PLCM). PLM describes the engineering aspect of...