Biological weapons ( often termed " bio-weapons " or " bio-agents ") are living organisms or replicating entities ( viruses ) that reproduce or replicate within their host victims.

In artificial selection, one species is bred selectively at each generation, allowing only those organisms that exhibit desired characteristics to reproduce.

* Nitrogen — to grow and reproduce more organisms to oxidize the carbon.

Cloning in biology is the process of producing similar populations of genetically identical individuals that occurs in nature when organisms such as bacteria, insects or plants reproduce asexually.

A gamete ( from Ancient Greek γαμέτης gametes " husband " / γαμετή gamete " wife ") is a cell that fuses with another cell during fertilization ( conception ) in organisms that reproduce sexually.

These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments.

Properties common to terrestrial organisms ( plants, animals, fungi, protists, archaea and bacteria ) are that they are cellular, carbon-and-water-based with complex organization, having a metabolism, a capacity to grow, respond to stimuli, and reproduce.

These proteins are crucial for cellular motility of single celled organisms and the sperm of many multicellular organisms which reproduce sexually.

The degree to which taxonomy depends on phylogenies differs between schools of taxonomy: numerical taxonomy ignored phylogeny altogether, trying to represent the similarity between organisms instead ; phylogenetic systematics tries to reproduce phylogeny in its classification without loss of information ; evolutionary taxonomy tries to find a compromise between them in order to represent stages of evolution.

Most organisms that reproduce sexually have pairs of chromosomes in each cell, with one chromosome inherited from each parent.

In certain other asterozoans the adult organisms reproduce asexually for a while before they mature and reproduce sexually.

In particular, phenomena such as kin selection and eusociality, where organisms act altruistically, against their individual interests ( in the sense of health, safety or personal reproduction ) to help related organisms reproduce, can be explained as gene sets " helping " copies of themselves ( or sequences with the same phenotypic effect ) in other bodies to replicate.

Although epigenetics in multicellular organisms is generally thought to be a mechanism involved in differentiation, with epigenetic patterns " reset " when organisms reproduce, there have been some observations of transgenerational epigenetic inheritance ( e. g., the phenomenon of paramutation observed in maize ).

While prokaryotic cyanobacteria themselves reproduce asexually through cell division, they were instrumental in priming the environment for the evolutionary development of more complex eukaryotic organisms.

In each new generation the organisms reproduce at random.

Judging from hyperthermophile organisms, the temperature limit is at about 120 ° C ( the recently discovered Strain 121 can reproduce at 121 ° C ), which limits the possible depth to 4-4. 5 km below the continental crust, and 7 or 7. 5 km below the ocean floor.

Microcosm studies are used to simplify food web research into semi-isolated units such as small springs, decaying logs, and laboratory experiments using organisms that reproduce quickly, such as daphnia feeding on algae grown under controlled environments in jars of water.

By contrast, gametes are cells that fuse during sexual reproduction, for organisms that reproduce sexually ; Germ cells are cells that give rise to gametes ; Stem cells are cells that can divide through mitosis and differentiate into diverse specialized cell types.

When the organisms are swallowed, they move into the intestine, where they can reproduce and cause symptoms.

They are filamentous, microscopic, absorptive organisms that reproduce both sexually and asexually.

Cell division also enables sexually reproducing organisms to develop from the one-celled zygote, which itself was produced by cell division from gametes.

Parasites account for as much as or more than half of life's diversity ; they perform an important ecological role ( by weakening prey ) that ecosystems would take some time to adapt to ; and without parasites organisms may eventually tend to asexual reproduction, diminishing the diversity of sexually dimorphic traits.

The shuffling of genes brought about by genetic recombination is thought to have many advantages, as it is a major engine of genetic variation and also allows sexually reproducing organisms to avoid Muller's ratchet, in which the genomes of an asexual population accumulate deleterious mutations in an irreversible manner.

In sexually reproducing multicellular organisms, the nucleotide substitution must arise within one of the many sex cells that an individual carries.

* Both lesions are caused by sexually transmissible organisms

In sexually reproducing organisms non-recombining chromosomes or chromosomal regions such as the mammalian Y chromosome ( with the exception of multi-copy sequences which do engage intrachromosomal recombination and gene conversion ), should also be subject to the effects of Muller's ratchet.

* Both lesions are caused by sexually transmissible organisms

The lack of evidence to the contrary suggests that the organisms reproduced sexually.

* tertiary sex ratio — ratio in sexually active organisms

Spermatozoa are the mature male gametes in many sexually reproducing organisms.

It is these new combinations of parts of chromosomes that provide the major advantage for sexually reproducing organisms by allowing for new combinations of genes and more efficient evolution.

Most multicellular organisms are unable to sexually reproduce at birth ( or germination ), and depending on the species, it may be days, weeks, or years until their bodies are able to do so.

Also, while in many organisms sexual maturity is strongly linked to age, many other factors are involved, and it is possible for some to display most or all of the characteristics of the adult form without being sexually mature.

All sexually reproducing organisms derive from a common ancestor which was a single celled eukaryotic species.

Technically this is not a problem of sex but a problem of some multicellular sexually reproducing organisms.

A male cannot reproduce sexually without access to at least one ovum from a female, but some organisms can reproduce both sexually and asexually.

While they can be a human safety hazard, it is productive for these ecosystems to burn out every once in a while so that new organisms can begin to grow and thrive.

Bernard Baars proposed that once in place, this " recursive " circuitry may have provided a basis for the subsequent development of many of the functions that consciousness facilitates in higher organisms.

Persistent organisms remain viable as they are capable of returning to a normal growth state once conditions in the host cell improve.

These plant communities cover approximately 9. 4 percent of the Earth's surface ( or 30 percent of total land area ), though they once covered much more ( about 50 percent of total land area ), in many different regions and function as habitats for organisms, hydrologic flow modulators, and soil conservers, constituting one of the most important aspects of the biosphere.

Scientists once thought that organic compounds are or could only be created by living organisms.

In the late 19th century, knowledge was increasing of the mechanisms by which living organisms become infected, how they manage infection once it has begun and, most importantly in the case of penicillin, the effect that natural and man-made agents could have on the progress of infection.

Some organisms can take opportunistic advantage of a similar process, where they engulf an alga and use the products of its photosynthesis, but once the prey item dies ( or is lost ) the host returns to a free living state.

It is a story not of an individual magically imprinting his personality on an institution — what Salonen has called the " empty hype " of conductor worship — but of an individual and an institution bringing out unforeseen capabilities in each other, and thereby proving how much life remains in the orchestra itself, at once the most conservative and the most powerful of musical organisms.

— The pre-Socratic Greek philosopher Xenophanes of Colophon argues that fossils of marine organisms show that dry land was once under water.

All multicellular organisms do not live or die all at once: not all cells in the body die instantaneously, nor are homeostatic " set points " constant through the life of an organism.

For instance, the two or three symbiotic organisms forming the composite lichen, while dependent on each other for survival, have to separately reproduce and then re-form to create one individual organism once more.

It is a story not of an individual magically imprinting his personality on an institution – what Salonen has called the " empty hype " of conductor worship – but of an individual and an institution bringing out unforeseen capabilities in each other, and thereby proving how much life remains in the orchestra itself, at once the most conservative and the most powerful of musical organisms.

Many species of plants, depending on the specific extraction conditions used, have immunomodulatory effects, as do various micro organisms that do, or once did, populate humans.

Overfishing has changed the ecological dynamics of marine communities, allowing some organisms to dominate reefs, that were once controlled by large reef fish populations.

Other member organisms once named " Thiobacillus " were transferred to Gammaproteobacteria:

According to the endosymbiont theory, mitochondria and chloroplasts were once free living organisms that were each taken up by a eukaryotic cell.

For example, the astrophysicist Frank Drake once speculated about the possibility of self-replicating organisms composed of such nuclear molecules living on the surface of a neutron star, a suggestion taken up in the science fiction novel Dragon's Egg by the physicist Robert Forward.

Many soil organisms, for example bacteria, can remain dormant through difficult times and reproduce quickly once conditions improve, making them resilient to disturbance.

However, once these turtles become adults there are very few organisms that prey on them.