Biology of animals and their division into kingdoms

The main link between inanimate nature and animals is plants. Plants are food for animals. But plants also need animals. Animals emit carbon dioxide, which is absorbed by plants. Predatory animals, eating herbivores, save plants from destruction.

The great ancient Greek scientist Aristotle first tried to divide the animal kingdom into groups; there were two of them: animals with blood (beasts, birds, amphibians and reptiles, fish) and animals without blood (insects, crayfish, mollusks). Animals are adapted to a variety of living conditions.

Various animals live in the forest - from small beetles, worms, birds to large mammals such as bear, wild boar, elk.

Bears are the furry heavyweights of predators. The Alaskan brown bear in its prime reaches a height of three meters and weighs as much as 700 kilograms. The largest of the bears is the white polar bear. Its length can be more than 3 meters, and this giant weighs a ton. On average, polar bears weigh between 300 and 500 kilograms. This beast has muscles of iron. It is saved from the cold by a thick layer of fat and a white skin with thick, warm fur. This animal is capable of swimming tens of kilometers in icy water. The polar bear has excellent hearing and vision. A polar bear can go without food for a very long time. But when there is prey, it immediately eats from 10 to 25 kilograms. Now there are only 10-20 thousand polar bears left on the planet. The polar bear is listed in the Red Book.

Moose feed on lush aspen and birch trees near water bodies. An adult moose can swim at a speed of 10 km/h. Moose are not afraid of ice. When northern bodies of water freeze, moose calmly walk on their surface. In summer, long thin legs easily carry the elk through any windbreaks, and when it finds itself on soft soil, its wide hooves move apart and prevent it from slipping.

But man began to domesticate some animals. Man received food and clothing from these animals; they helped in hunting, protected, and transported man and his property. These animals were looked after, shelters were built for them, they were fed, treated, and their offspring were raised.

People domesticated the first wild pigs about six and a half thousand years ago.

The domestic donkey evolved from the wild African donkey.

Sheep and goats were domesticated by humans about 10 thousand years ago.

About 40 million years ago, a small hare-like animal lived in the subtropical forests of North America. It was from him that the mammal we know as the camel came from.

There are 15 million camels on earth and they are all strong and hardy animals. But the hardiest animals among them are the nine hundred wild camels that live in the Gobi Desert.

The camel has many adaptations to live in the desert. long thick eyelashes protect his eyes from sand.

The last wild camels live in Mongolia in the Gobi Desert. They live in herds.

Of the four relatives of the camel in South America, two have been domesticated. The llama is used as a beast of burden, and the alpaca survives only in the mountain villages of the indigenous Andean people. He is kept because of his very good wool.

Mammals that move on the ground have four legs. They feed their young with milk secreted by special glands. In mammals that lead an aquatic lifestyle, for example, in the dolphin and seal, the legs have turned into flippers, and in the whale, the hind legs have formed a tail.

Man also belongs to animals, to the class of mammals. Because it feeds on both plants and animals. Its main difference from other animals is the special development of the brain, which made it a reasonable person.

Dolphins are one of nature's most exciting mysteries. In ancient times, they tried to predict the future among the sea waves and by their behavior. They often rescue shipwrecked people by carrying them closer to land on their backs. To communicate with each other, dolphins have developed a complex language based on sounds. Dolphins are very trusting and sociable. Dolphin calves can be seen off the European coast; they are born in the summer after ten months of pregnancy of the female and remain with their family for a long time.

Dolphins and many other aquatic mammals have a very impressive set of teeth, up to 260. Dolphins feed on large and small fish and shellfish.

The ostrich is the largest living bird. An adult ostrich reaches a height of two and a half meters and weighs about 100 kilograms. Ostrich speed is up to 50 km/h. Ostriches live in groups of 10-50 individuals.

The smallest birds are Hummingbirds

The beauty of hummingbird outfits is inimitable. The smallest hummingbird weighs 2 g, with a length with beak of 5-6 cm. Most hummingbirds do not exceed 3-7 g; giants, such as the giant hummingbird, weigh 18-20 g.

Hummingbirds feed on flower nectar. Hummingbirds never land on the ground, but hang upside down at night, like bats. They heroically defend their nests with chicks. They fearlessly attack the enemy and throw even tree snakes to the ground with a strong blow to the eye.

Amphibians and reptiles are called cold-blooded animals because their body temperature depends on the temperature of the environment. When it's warm, they're warm and lively. When it gets cold, their body temperature drops and they become inactive. Amphibians breathe through their lungs and skin. Amphibians spend part of their lives in water, in it, and in it they lay eggs.

The frog, toad and newt are amphibians.

Toads are nocturnal, unlike frogs, and need water even less. Toads have a length of 12-15.20 centimeters. They live throughout Europe, in Asia Minor and Central Asia, as well as in Japan. Central America is home to the Aha toad. Her entire skin is covered with warts with small thorns that can hurt her. Mucus contains a very strong poison that retains its properties for many years.

Newts are not at all afraid of the cold. They can freeze into ice in winter, and as soon as it melts, they can come to life without much difficulty.

From a very early age, newts feed on animal food, eating small crustaceans, worms and insects. Newts have very poor vision, so hunting is very difficult for them.

Snakes, lizards, turtles and crocodiles are reptiles. Reptiles have dry, scaly skin. They breathe with their lungs.

The largest snake on our planet is the anaconda. Its length is 8 meters 29 centimeters. Anacondas usually live in water. They swim well, dive well and can rest for a long time. Anaconda weight is up to 135 kg. The gestation period is 6-7 months, the number of cubs depends on the size of the female. They move silently and attack large animals, such as pigs, and sometimes decide to attack humans.

The thick, shiny skin of the anaconda is isolated and used to make suitcases, boots, and horse hats. Meat and fat are eaten.

The anaconda has no enemies other than people.

Crocodiles are one of the most ancient inhabitants of our planet. There are currently 21 species of crocodiles on earth.

Crocodiles are called aquatic reptiles because they spend most of the day in the water. They love to bask on the shore.

Like all reptiles, crocodiles lay eggs. There are from 10 to 100 eggs in a clutch. They are very similar to Chicken eggs. Crocodiles are very caring parents. They guard the clutch and help newborns get out of the egg. The length of the hatched crocodile is only 20-30 cm.

Only after 10-15 years do they grow into a real crocodile. The length of an adult crocodile reaches 8 meters. Crocodiles live up to 100 years. The crocodile feels as good on land as it does in water. If necessary, he can run at a speed of 12 km/h.

The main food of crocodiles is fish. Some hunt buffalo. Crocodiles are dangerous to humans.

Animals of the fish class are very diverse in appearance.

They can be tiny, which we can see in an aquarium, and huge, like a whale shark, up to 18 m long and weighing equal to six elephants. Among the fish there are also those that have learned to soar in the air with the help of large pectoral fins. Some flying fish, taking off in a jump above the water, can stay in the air for up to 90 seconds. During this time, they fly almost a kilometer, escaping from the predators pursuing them.

The most terrible fish on Earth is the shark. They appeared 400 million years ago, even earlier than dinosaurs. The shark is a voracious and predatory fish.

The shark does not swim in the ocean alone. She has a constant faithful companion - the pilot fish. These are fish smaller than sharks, they show the way for the shark. The pilot fish helps the shark find food and warns of danger.

Clams have a soft, boneless body protected by two hard shells. But some mollusks come without a shell. – these are octopuses and squids.

Squid has no bones and is an invertebrate animal. Its main difference from an octopus is its long, elongated body and seven tentacles. The octopus has eight of them. The most terrible enemy of squid is the sperm whale.

Squids feed on large fish and even dolphins. The largest squid was 18 meters long and weighed about 8 tons.

Octopus is close relatives of squid. Octopuses are very poisonous. Octopuses do not have shells, they only have a soft mantle covering their body. At the back of the octopus there is a funnel-shaped chamber into which water flows. The octopus extracts oxygen from it, just like fish. With the help of this camera, the octopus is able to move quickly. The octopus can release water from there with such force, thus saving itself from enemies. We know more than 100 species of octopuses. But they are all small animals, no more than half a meter long. Three or four species can be considered large. This is the common Doflein's octopus, the Apollo octopus. Dofflein's octopus reaches a length of three meters and weighs about 25 kilograms. Apollo can be called a giant. Its tentacles are huge - up to 5 meters, the head and body are only 30 centimeters.

Most mollusks live in water, but there are also land ones - snails, slugs.

Snails feed on animal food. Snails and slugs breathe using a single lung.

The snail is shaggy - covered with thin hairs. The shell is 5 mm high, 8-9 mm wide. Lives near bushes, on the ground in the forest floor, under stones. Most snails lay eggs. Some lay several very large eggs, others a lot of small ones

Slugs have a naked body. Slugs have 4 forward-facing tentacles on their heads. Slugs have 4 forward-facing tentacles on their heads. Slugs produce a lot of mucus. It primarily protects the shellfish from drying out.

The largest of the mollusks, the giant clam, has a shell weighing 180-223 kilograms. It lives on coral reefs. East Indies

There are several million species of animals on earth, most of which are insects. Among insects, the largest order is beetles. No one knows how many there really are, which is why scientists discover so many new species every year. Many insects ensure the reproduction of plants and then distribute their seeds.

Mushrooms

Mushrooms are neither plants nor animals. Mycology is the study of mushrooms, from the Greek “mykes” - mushroom and “logos” “concept” thought - the role of mushrooms in nature is directly opposite to the role of grass or trees. Fungi, together with bacteria, destroy and return carbon dioxide to the atmosphere and minerals to the soil.

Most fungi reproduce using special tiny cells called spores. Some asexual spores are formed directly from mycelium cells.

Reproduction with their help is called asexual reproduction. First, two cells from different myceliums form one nucleus. After some time, the cell divides again: new cells turn into spores.

Everyone has their own favorite habitat: boletus mushrooms settle near birch trees. Boletus love aspen trees. Porcini mushrooms grow near birches, near oaks, and near coniferous trees. Mushrooms are tasty and nutritious. Man has always eaten them.

But not all mushrooms are edible. Among them there are inedible and poisonous.

The most poisonous mushroom is the toadstool. Even a small piece of it eaten is fatal. Mushrooms are capable of accumulating harmful toxic substances in their fruiting body.

There is a kefir mushroom and a mushroom for making cheese. You can drink an infusion of kombucha, which lives in water. A valuable medicine, penicillin, is obtained from a special mold fungus.

Bacteria

There is another large group of organisms that are tiny and invisible to the naked eye. They live everywhere: in the air, in the water, in the soil. These are bacteria and viruses. People discovered them only when the microscope was invented.

The first microscope was invented in 1673 by a Dutch master.

Despite all their invisibility, microscopic organisms play a huge role in the life of the Earth, in the life of plants, animals and humans.

We have friends and enemies among bacteria. There are bacteria and viruses called typhus, others cause measles, others - tuberculosis, and others - dysentery.

Bacteria can enter our body in different ways. If, for example, only one bacteria enters the human body, then after 12 hours there may already be several billion of them.

Bacteria thrive in water.

They withstood two-week stays in a deep vacuum and did not die in outer space. Some bacteria produce organic substances themselves with the help of sunlight. Only oxygen is not released during this process.

There are also beneficial bacteria - they live in our intestines. They help the body convert food. They, like animal nurses, save us from dead plants and animals. Many animals simply need bacteria. Various bacteria help humans make silk, coffee produces tobacco, one of the most promising ways to use bacteria was discovered only towards the end of the 20th century.