Студопедия
Главная страница | Контакты | Случайная страница

АвтомобилиАстрономияБиологияГеографияДом и садДругие языкиДругоеИнформатика
ИсторияКультураЛитератураЛогикаМатематикаМедицинаМеталлургияМеханика
ОбразованиеОхрана трудаПедагогикаПолитикаПравоПсихологияРелигияРиторика
СоциологияСпортСтроительствоТехнологияТуризмФизикаФилософияФинансы
ХимияЧерчениеЭкологияЭкономикаЭлектроника

Types of communications and mutual relations between organisms. Parasitism.

Читайте также:
  1. A content of legal relations.
  2. BETWEEN
  3. between
  4. II. The types of word stress.
  5. SIZE and TYPES of BUSINESS ORGANIZATIONS
  6. Special types of business organizations
  7. The phonetic nature and types of speech rhythm in different languages.
  8. Theory of oppositions. Types of oppositions. Oppositions in morphology
  9. Types of connotation

Parasitism. In this association one organism [the parasite] benefits and the other [the host] is adversely affected [weakened, sickened, damaged etc]. This description would also fit the relationship between a carnivore and its live prey and a herbivore and the plant it feeds on, especially if they are very specialized in the food they eat. We normally define parasites as organisms which cannot survive without their host and have special modifications to their body or their life cycle for this association.

A parasitic relationship is one in which one member of the association benefits while the other is harmed. This is also known as antagonistic or antipathetic symbiosis. Parasitic symbioses take many forms, from endoparasites that live within the host's body to ectoparasites that live on its surface. In addition, parasites may be necrotrophic, which is to say they kill their host, or biotrophic, meaning they rely on their host's surviving. Biotrophic parasitism is an extremely successful mode of life. Depending on the definition used, as many as half of all animals have at least one parasitic phase in their life cycles, and it is also frequent in plants and fungi. Moreover, almost all free-living animals are host to one or more parasite taxa. An example of a biotrophic relationship would be a tick feeding on the blood of its host.

 

16bilet

Dynamic parameters of a population: birth rate, death rate, growth rate of the population.

Symbiosis. (from Ancient Greek σύν "together" and βίωσις "living") is close and often long-term interaction between two or more different biological species. In 1877, Bennett used the word symbiosis (which previously had been used to depict people living together in community) to describe the mutualistic relationship in lichens. In 1879, the German mycologist Heinrich Anton de Bary defined it as "the living together of unlike organisms."

The definition of symbiosis is controversial among scientists. Some believe symbiosis should only refer to persistent mutualisms, while others believe it should apply to any types of persistent biological interactions (i.e. mutualistic, commensalistic, or parasitic).

Some symbiotic relationships are obligate, meaning that both symbionts entirely depend on each other for survival. For example, many lichens consist of fungal and photosynthetic symbionts that cannot live on their own.

Symbiotic relationships include those associations in which one organism lives on another, or where one partner lives inside the other.

Cosmopolitans, ubikvists and endemics. Depending on size of area and character of distribution there are cosmopolitans, ubikvists and endemics. Cosmopolitans are species of plants and animals which representatives meet on a greater part of inhabitant areas of the Earth (for example, the room fly, grey rat). Ubikvists a re species of plants and animals with wide ecological valency, they are capable to exist in various conditions of environment, have extensive areas (for example, a reed ordinary, the wolf). Endemics are species of plants and animals which have the small limited areas (often they are met on islands of an oceanic origin, in mountain areas and the isolated basin).

 

17bilet

Pedosphere (a soil cover) as a part of biosphere. Pedosphere (a soil cover) as a part of biosphere. The pedosphere (from Greek πέδον pedon "soil" or "earth" and σφαίρα sfaíra "sphere") is the outermost layer of the Earth that is composed of soil and subject to soil formation processes. It exists at the interface of the lithosphere, atmosphere, hydrosphere and biosphere. The sum total of all the organisms, soils, water and air is termed as the "pedosphere". The pedosphere is the skin of the Earth and only develops when there is a dynamic interaction between the atmosphere (air in and above the soil), biosphere (living organisms), lithosphere (unconsolidated regolith and consolidated bedrock) and the hydrosphere (water in, on and below the soil). The pedosphere is the foundation of life on this planet. There is a realization that the pedosphere needs to be distinctly recognized as a dynamic interface of all terrestrial ecosystems and be integrated into the Earth System Science knowledge base. Also, the pedosphere needs to be studied, valued, enhanced and treated in a sustainable and an ethical manner.

The structural organization of ecosystem. From the point of view of trophic structure ecosystem is divided into two circles – autotrophic and heterotrophic (Odum, 1986).

1. The top autotrophic circle, or «a green belt» is a circle of plants or their parts containing a chlorophyll where fixing of light energy, use of simple inorganic compounds and accumulation of complex organic compounds prevail.

2) The bottom heterotrophic circle, or «a brown belt» is a circle of soil and the precipitation, decompositing substances, roots and etc. in which use, transformation and decomposition of complex compounds prevail.

From the biological point of view in structure of ecosystem there are following components (Odum, 1986):

1) inorganic substances;

2) organic compounds;

3) air, water and substrate medium;

4) producers;

5) macroconsumers;

6) microconsumers.

1. Producers are the autotrophic organisms, which are capable to produce organic substances from inorganic, using photosynthesis or chemosynthesis (plants and autotrophic bacteria).

2. Consumers (macroconsumers) are the heterotrophic organisms consuming organic substance of producers or others consumers (animals, heterotrophic plants, some microorganisms). There are consumers of the first order and the second order.

3. Reducers (microconsumers, destructors) are the heterotrophic organisms, eating fossils and decomposing them to mineral substances (saprotrophic bacteria and mushrooms).

As a rule, in any ecosystem it is possible to note three functional groups of organisms: producers, consumers and reducers. In ecosystems formed only by microorganisms, consumers are absent. Each group consists of set of the populations occupying ecosystem.

In ecosystem, food and power bonds proceed in a line: producers->consumers-> reducers.




Дата добавления: 2014-12-15; просмотров: 134 | Поможем написать вашу работу | Нарушение авторских прав




lektsii.net - Лекции.Нет - 2014-2025 год. (0.006 сек.) Все материалы представленные на сайте исключительно с целью ознакомления читателями и не преследуют коммерческих целей или нарушение авторских прав