The animal world that surrounds us is very diverse. Flying, crawling, swimming, walking and running: "Each creature in pairs," as the Bible says. And about how many of these "creatures", and what are the animals that live on the ground, in air and water, read in this article.
There is a science that systematizes all the inhabitantsbiosphere. It is called taxonomy and determines what animals are. Science is able to determine the degree of kinship between organisms, which can not always be due to external similarity. It happens that similar animals are related to different orders, and unlike (armadillos, anteaters, sloths) are united in one unit. The definition of the kinship of these or other creatures depends on both origin and paleontological and genetic research.
All living things on Earth are divided into five largekingdoms. The world is inhabited by bacteria, protozoa, fungi, plants and animals (multicellular creatures that can move, feed on plants or other animals). The animal kingdom is divided into 10 types, respectively, among which the most progressive is chordates (they have a primary skeleton axis available). The most highly developed are vertebrates that have a spine transformed from a chord.
Types, in turn, are divided into classes. In vertebrate animals, five classes are distinguished: fish, amphibians, reptiles, birds and mammals. The latter has the highest organization among all vertebrates. There are also two subclasses of these animals: oviparous and viviparous. The first lay eggs like birds, for example, but their babies are fed milk. The second (and marsupials, and placental) give birth to or underdeveloped cubs, which are then in a special mother bag, or give birth to already formed babies.
To find out what animals are, you can andmore in detail. Subclasses are divided into groups, detachments - for childbirth, and childbirth - for species. Today on our planet live up to four thousand mammals. And each of the animals individually is called an individual.
Will we find out what other animals are there? Vegetable, omnivorous, carnivorous. Green plants provide themselves with food through photosynthesis, which converts air, water, solar energy into the most complex compounds. Animals do not know how to do this. They have to eat plants or their own kind. So the food chain is formed.
Most of the existing animal specieseat plant food. They use certain parts of plants and their varieties, most suitable for the digestive system of the organism. Everyone has their own preferences: leaves and stems, roots and bark. Much of this can be difficult to digest, but this process in herbivorous animals helps the simplest microorganisms and bacteria that live in the stomach. In each class, type, detachment there are herbivorous. These are insects: beetles, bees, butterflies, grasshoppers, and fish: for example, representatives of bone, and reptiles: turtles, and birds: passerines, chicken. In the class of mammals, marsupials, artiodactyls, odd-ungulates, rodents, hares, proboscis are herbivorous. Some whales also prefer phytoplankton. In the food chain, these animals are called second-level organisms (trophic).
Continue to find out what are the animals? Omnivores are the next type we will consider. Interestingly, many species of organisms that feed mainly on plants, sometimes do not mind eating meat. And carnivores also sometimes do not disdain to try anything vegetarian. Such animals are called omnivores. As an example, you can bring some insects (cockroaches, etc.), ostriches, rats, pigs, most bears, anthropoid apes (chimpanzees and others). This applies to people.
It is interesting that the digestive system of omnivoresnot so narrowly specialized. Therefore, their stomachs can digest both plant and animal food. The omnivorous mammals also do not have fangs, as in predators, and incisors are located in the front of the mouth.