Human symbionts are examples. Ecological Dictionary What is symbiosis, what does it mean and how to spell it correctly. Harm from epiphytes

What is Symbiosis

Symbiosis is a biological term that refers to a beneficial relationship between two or more living organisms different types. In addition to being used in biology, this word is also used in other areas of life to describe any mergers that imply a benefit.

What is SYMBIOSIS - definition and concept in simple words.

In simple words The symbiosis is a form of interaction between several organisms in which either one or all of them benefit. As a rule, the motivational factor for creating a symbiotic relationship in nature is the simplest needs, such as food, protection, habitat and reproduction. So, for example, sticking fish attach themselves to larger marine predators, which provide themselves with protection and food in the form of remnants of prey. There are a huge number of similar examples of interaction, and we will talk about them in more detail a little later.

If you step aside from biological terminology, then the word "symbiosis" can be heard in the field of business, art, technology, politics, and so on. For example, quite often in the media one can hear wording like: “symbiosis of business and politics”, which literally means close interaction between political circles and business.

Types, forms and types of symbiosis.

In general terms, symbiotic relationships can be divided into the following criteria:

Mutualism is symbiosis in which organisms benefit each other. This type of "union" is the most common in nature and can be both optional and mandatory for different species. With such a symbiosis, species can interact both physically and biochemically. For example, birds and insects that feed on flower nectar have a symbiotic relationship with these flowers. They receive nectar in the form of food, and in return they help with pollination by carrying pollen from one flower to another. In the same way, the sea anemone and the clown fish are in symbiosis, which protect each other from their enemies.

Commensalism is a relationship between species that benefits one organism without substantially harming or helping another. TO this species connection is the above example with sticky fish.

Symbiosis examples.

An amazing example of a slightly creepy, but very interesting symbiosis is the relationship between the Cordyceps fungus and insects. For example, the spores of a zombie fungus attach themselves to an ant and penetrate its tissues using enzymes. After that, the fungus changes the behavior of the ant and subdues it. The ant moves away from its colony, climbs up the stem of the plant, and unnaturally places its mandibles deep into the leaf. After attaching to the leaf, the ant loses the ability to move, and the fungus begins to grow from its body. Thus, being at a height, the zombie fungus most effectively spreads its spores.

Symbiosis is a form of relationship in which both organisms benefit from each other. In other words, it is a mutually beneficial cohabitation. An organism that lives in symbiosis is a symbiont.

Types of symbiosis

In biology, the term symbiosis can be used in two ways. different meanings. As already mentioned, this is a form of cohabitation that benefits everyone. However, in biology there is an older definition - mutualism. In any case, the word "symbiosis" was introduced in 1879 by the German botanist and microbiologist Heinrich Anton de Bary. The term had a meaning as the beneficial existence of different organisms, regardless of whether it is beneficial to them or not. The symbiosis is divided into:

The third type denoted symbiosis, from which one organism benefited, and for the second it had a neutral meaning. This type of cohabitation can be divided into: zoochory (animals and plants interact, animals help plants carry seeds and fruits), synoikia (lodging, one is indifferent, the other is beneficial), phoresia (symbiosis of different species, in which the symbiont bigger size wears a smaller one), epibiosis (settlement of one organism on another), epioikia (a symbiont lives on the surface of another without harming it), entoikia, paroikia. However, all these species have one similarity: one of the symbionts forms a special form of habitat for the other.

Related materials:

Why are mushrooms not plants?

Examples of symbiosis

mushrooms and trees

Many mushrooms ( White mushroom, boletus) have a close relationship with the roots of trees, having benefits both for themselves and for the plant. With such a symbiosis, the small roots of certain trees are braided with mycelium threads (hyphae), penetrating the roots and located between the cells. This formation is called mycorrhiza. Mycorrhiza was discovered by the Russian botanist Franz Mikhailovich Kamensky in 1879, and the German scientist David Albertovich Frank gave the name to this type of symbiosis.

Can spread only one, certain type of insect. Such relationships are always successful when they increase the chances of both partners to survive. The actions carried out in the course of symbiosis or the substances produced are essential and irreplaceable for the partners. In a generalized sense, such a symbiosis is an intermediate link between interaction and merging.

A kind of symbiosis is endosymbiosis (see Symbiogenesis), when one of the partners lives inside the cell of the other.

The science of symbiosis is symbiology.

Mutualism

Mutually beneficial relationships can be formed on the basis of behavioral responses, for example, as in birds that combine their own food with the distribution of seeds. Sometimes mutualistic species enter into close physical interaction, as in the formation of mycorrhiza (fungal root) between fungi and plants.

The close contact of species in mutualism causes their joint evolution. A typical example is the mutual adaptations that have developed between flowering plants and their pollinators. Mutualist species often co-populate.

Commensalism

Depending on the nature of the relationship of commensal species, three types are distinguished:

• the commensal is limited to the use of the food of an organism of another species (for example, an annelids from the genus Nereis lives in the coils of the shell of a hermit crab, feeding on the remnants of the food of the crab);
• the commensal is attached to the organism of another species, which becomes the "master" (for example, a fish stuck with a sucker fin attaches to the skin of sharks and other large fish, moving with their help);
• commensal settles in internal organs host (for example, some flagellates live in the intestines of mammals).

An example of commensalism is legumes (for example, clover) and cereals growing together on soils poor in available nitrogen compounds, but rich in potassium and phosphorus compounds. Moreover, if the cereal does not suppress the legume, then it, in turn, provides it with an additional amount of available nitrogen. But such a relationship can only last as long as the soil is poor in nitrogen and the grasses cannot grow strongly. If, as a result of the growth of legumes and the active work of nitrogen-fixing nodule bacteria, a sufficient amount of nitrogen compounds available for plants accumulates in the soil, this type of relationship is replaced by competition. Its result, as a rule, is the complete or partial displacement of less competitive legumes from the phytocenosis. Another variant of commensalism: one-sided help of a “nanny” plant to another plant. So, birch or alder can be a nanny for spruce: they protect young spruces from direct sun rays, without which a spruce cannot grow in an open place, and also protect the seedlings of young Christmas trees from squeezing them out of the soil by frost. This type of relationship is typical only for young spruce plants. As a rule, when the spruce reaches a certain age, it begins to behave like a very strong competitor and suppresses its nannies.
Shrubs from the families of labiales and Asteraceae and South American cacti are in the same relationship. Possessing a special type of photosynthesis (CAM metabolism), which occurs during the day with closed stomata, young cacti become very overheated and suffer from direct sunlight. Therefore, they can only develop in the shade under protection. drought-resistant shrubs. There are also numerous examples of symbiosis that is beneficial to one species and does not bring any benefit or harm to another species. For example, the human intestine is inhabited by many types of bacteria, the presence of which is harmless to humans. Similarly, plants called bromeliads (which include, for example, pineapple) live on tree branches, but receive nutrients from the air. These plants use the tree for support without depriving it of nutrients. Plants make their own nutrients, they don't get them from the air.

Commensalism is a way of coexistence of two different types of living organisms, in which one population benefits from the relationship, and the other does not receive any benefit or harm (for example, common silverfish and humans).

Symbiosis and evolution

In addition to the nucleus, eukaryotic cells have many isolated internal structures called organelles. Mitochondria, one type of organelle, generate energy and are therefore considered the powerhouses of the cell. Mitochondria, like the nucleus, are surrounded by a bilayer membrane and contain DNA. On this basis, a theory has been proposed for the emergence of eukaryotic cells as a result of symbiosis. One of the cells engulfed the other, and then it turned out that together they cope better than individually. This is the endosymbiotic theory of evolution.
This theory easily explains the existence of a bilayer membrane. The inner layer originates from the membrane of the engulfed cell, while the outer layer is part of the membrane of the engulfed cell wrapped around the alien cell. It is also well understood that the presence of mitochondrial DNA is nothing more than remnants of the alien cell's DNA. So, many (perhaps all) of the eukaryotic cell organelles at the beginning of their existence were separate organisms, and about a billion years ago they joined forces to create a new type of cell. Therefore, our own bodies are an illustration of one of the oldest partnerships in nature.

It should also be remembered that symbiosis is not only the coexistence of different types of living organisms. At the dawn of evolution, symbiosis was the engine that brought unicellular organisms of the same species into one multicellular organism (colony) and became the basis for the diversity of modern flora and fauna.

Examples of symbioses

• Endophytes live inside the plant, feed on its substances, while releasing compounds that promote the growth of the host organism.
• Transportation of plant seeds by animals that eat the fruits and excrete the undigested seeds along with the droppings elsewhere.

insects/plants

mushrooms/algae

• A lichen is composed of a fungus and an algae. Algae through photosynthesis produce organic matter(carbohydrates) used by the fungus, which supplies water and minerals.

Animals/algae

mushrooms/plants

• Many fungi receive nutrients from the tree and supply it with minerals (mycorrhiza).

insects/insects

• Some ants protect ("herd") aphids and receive sugar-containing secretions from them in return.

see also

Notes

Literature

• Margelis L. The role of symbiosis in cell evolution. - M: Mir, 1983. - 354 p.
• Douglas A.E Symbiotic interaction. - Oxford University. Press: Oxford:Y-N, Toronto, 1994. - 148 p.

Links

Wikimedia Foundation. 2010 .

Symbiosis- (from Greek symbiosis cohabitation), close cohabitation of organisms of two or more species, which, as a rule, has become necessary and beneficial for both partners (symbionts). Symbiosis in marine animals was discovered by K. Möbius (1877). According to the degree of connection ... Ecological dictionary

symbiosis- a, m. symbiose f. gr. symbiosis. biol. The cohabitation of organisms of different species, usually bringing them mutual benefit, for example. fungus and algae that together form a lichen. SIS 1954. Symbiosis of hermit crab and sea anemone. BAS 1. Vinogradov completed ... ... Historical Dictionary of Gallicisms of the Russian Language

What is symbiosis in biology: definition

Symbiosis is any association between two various types populations. Its study is the quintessence of systems biology, which integrates not only all levels of biological analysis, from molecular to ecological, but also studies the relationships between organisms in the three domains of life. The development of this area is still at its early stage, but in the near future the results will not be long in coming.

Types of symbiosis

What is symbiosis in biology (grade 5)? Symbiosis is a relationship between two or more organisms living in close contact with each other. An interaction occurs when two species live in the same place and one or both benefit from the other. Predation indirectly falls under this definition, since it can also be considered as a kind of symbiosis.

Mutualism

Mutualism is one of the best known and most ecologically significant types of symbiosis. Such relationships are, for example, insects and plants (pollination). Such cooperation is favorable and mutually beneficial for both parties. Insects, birds and even some mammals get their food in the form of nectar. The plant, on the other hand, gains a great reproductive advantage in that they are able to transfer their pollen to other plants.

Since plants do not often end up together, it is rather problematic for them to perform a reproductive function without intermediaries. In this case, symbiosis is simply vital for them, and in the full sense of the word. Without pollinators, many plants could simply fade away. On the other hand, without pollinating plants, many insects themselves would be in big trouble. This is truly a mutually beneficial alliance.

Examples of symbiosis in biology are not limited to this. Another fascinating variant of beneficial cooperation can be seen in the relationship of certain species of ants and aphids. Aphids are tiny, soft insects that feed on plant sap and excrete a certain amount of sugar and water as waste. This becomes suitable food for some species of ants. In turn, the ants often carry them to a new place, thus providing additional sources nutrition.

Commensalism

What is symbiosis in biology? First of all, this is cooperation. One of the rarest types of symbiosis found in nature is commensalism. In this case, only one side benefits. The second from such an agreement is neither hot nor cold. Finding examples of it is quite a difficult task. However, several examples can be given.

An example of commensalism can be demonstrated by some desert lizards that find their place of residence in abandoned rat or snake holes. The lizards receive shelter while the other animal receives nothing in return.

What is symbiosis in biology? In simple terms, we can say that this is a positive, negative or neutral cooperation between different types of organisms.