What is a power circuit? Presentation materials

Many of the living organisms on the planet Earth feed on organic food. It can be plants, the bodies of other creatures, the products of their life activity and decomposition. By and large, what is a power circuit? This is the situation where nutrients move in a consistent way from one organism to another.

Producers

In order to understand what a food chain is, it is necessary to find out what it consists of. There are creatures that begin this sequence. They are called producers. These creatures (autotrophic) take energy to carry out their vital activity from materials that are not organic. These include green plants and many species of various bacteria that live in water, air, on land and underground. Thus, plants can be powered by photosynthesis in sunlight. And microorganisms use mineral salts and gases to function.

Consumables

In determining what the food chain is, the next link is constituted by consumers, which, in turn, are already heterotrophic organisms. Among them, the first order - those that feed on producers: microorganisms and plants. The second order is predators: those who feed on other animals. Next, consuments of the third, fourth order and so on, until the sequence is closed.

Vegetable-eating

In order to better understand what is a food chain, let us turn to the classification of animals according to the composition of the food they consume. Animals that eat only plant foods are called herbivores or herbivores. Such beings exist in practically any of the detachments, classes, types of the animal kingdom. Invertebrates - ringworms, beetles, butterflies and grasshoppers, bees and wasps. Vertebrates - many fish, reptiles (turtles), non-predatory birds. Mammals have herbivores - deer and deer, horses and zebras, cows, elephants, many rodents.

Carnivores, or predators

The chain of supply is a link, complementary to each other. Without one follower, there would simply be nothing to eat, which leads to the extinction of a certain species of animals. As has happened many times in nature, when the food base of predators is exterminated, they gradually disappear themselves. So, carnivores close the food chain. One or more species of predators feeding on herbivorous animals may participate in the chain . As a rule, the final link is the largest and strongest animal. In the ocean, for example, a shark. In the middle forest this will be a wolf or a lynx. Usually, such predators do not happen much. Their nutritional base (and hence the energy reserve for vital activity) is limited, although meat food gives more energy to animals, and the consumption of food predators spend less time than herbivores. Among the most famous sea predators, for example, the blue shark.

Among the land - tigers, lions, wolves. They all hunt and feed on the meat of other animals.

Omnivorous animals

The chain of power is the transfer of energy from one being to another. At the same time, with each next link, energy losses are usually realized. So, for example, when a lion eats an antelope, it contains only a fraction of the energy that the animal received during life. But there are also animals that are equally inclined to eat both plant and animal food. They are called omnivores. They are also quite a lot in nature. Insects and birds, rats and pigs, bears and chimpanzees. And of course, man. At omnivorous mammals there are no sharp canines, and in front of the jaw are incisors, behind - molars. And the stomach is adapted for processing both animal and plant foods.

Scavengers

A special role in nature is played by scavenger animals, which feed on corpses and remains of other animals. They are also quite a lot: from microorganisms and insects to vertebrates - birds and mammals. They destroy dead matter, using the liberated energy, reprocessing it and using it for their vital functions. If it were not for these creatures, the whole planet would be covered by the remains of the dead for the entire time of its existence. And bacteria take an active part in the food chain, as if completing the processing of energy into a new quality, preparing the soil for plants.

What is a power circuit? Definition

Thus, having analyzed all of the above, one can approach the meaning of the term. What is a power circuit? Definition is given by dictionaries and encyclopedias. Firstly, these are the organisms of all kingdoms (bacteria, protozoa, plants, fungi, animals), which are related to each other by the relationship "food-consumer". The beings of the next link of the chain consume the representatives of the previous link, using the substance and energy to carry out their own vital activity. Thus, the transfer and conservation of energy and matter takes place, their circulation in nature is realized. Secondly, when moving from one link of the chain to the other, most of the energy resources are lost (up to 90% in some cases), which are usually dissipated in the form of heat losses. Perhaps, therefore, the number of links of the CPU (food chain) is no higher than 3-5 (maximum).

Recommendations for the presentation on the theme "Chain of food: what is it?"

When presenting this topic, it is recommended to use slides depicting the organisms participating in food chains, to focus on what kind of food the animals eat, how they participate in the process. You can also offer a homemade composition: "Write what are food chains and what kinds of animals you know can participate in them in the terrestrial or aquatic environment."