Animals

ANIMALS

Animals are multicellular organisms that obtain energy by eating food. They live in a vast range of habitats, from deserts and Arctic tundra to the deep-sea floor. Like all living things, animals show similarities and differences that enable them to be classified into groups. Birds, for example, are the only animals that have feathers, while mammals are the only ones that have fur. Animals are also classified according to other characteristics, including their internal anatomy, patterns of development, and genetic makeup. Scientists divide the animal kingdom into approximately 30 groups, each called a phylum. One phylum of animals, the chordates, has been more intensively studied than has any other, because it comprises nearly all the world’s largest and most familiar animals as well as humans. This phylum includes mammals, birds, reptiles, amphibians, and fish together with a collection of lesser-known organisms. Some invertebrate phyla contain relatively few species. Vertebrates are customarily divided into cold-blooded (an animal whose temperature is dictated by its surroundings) and warm-blooded animals (is one that keeps its body at a constant warm temperature by generating internal heat). Few parts of Earth’s surface are entirely devoid of animal life. Animals cannot survive in places where water is unavailable or permanently frozen, or where temperatures regularly exceed 55° C. However, in all habitats that lie between these extremes, animal life abounds. In the seas and oceans, the greatest diversity of animal life is found in habitats close to shores. On land, animal habitats are strongly influenced by climate, the combination of precipitation and temperature conditions experienced in a region. For land animals, the most testing habitats are ones that experience intense drought or extreme cold. Animals all feed on organic matter, but their diets and way of obtaining food vary enormously. Some animals are omnivores, meaning that they are capable of surviving on a very wide range of foods. Many other animals have extremely precise requirements and cannot deviate from their highly specialized diet. In general, animals eat plants, other animals, or the remains of living things. Plant-eaters, or herbivores, often do not have to search far to find things to eat, and in some cases—for example wood-boring insects—they are entirely surrounded by their food. But plant food can be difficult to digest and is often low in nutrients. Carnivores live on flesh from other animals that is often nutrient-rich and easy to digest but difficult to obtain. Finding and capturing this kind of food calls for keen senses. Some mammalian predators increase their chances of success by hunting in groups. Some position themselves in a suitable location and wait for their prey to come within striking distance. In predatory animals, teeth or other mouthparts often play a part in catching and subduing food as well as in preparing it for digestion. Wherever they live, animals need oxygen in order to survive. By breathing, or respiring, they extract oxygen from their surroundings and dispose of carbon dioxide waste. Very small animals do not need any special adaptations for obtaining oxygen. Oxygen simply diffuses in through their body surface, with carbon dioxide traveling out the same way. To obtain sufficient oxygen, large animals have to boost their oxygen intake by using special respiratory organs. In water, many animals breathe by using gills. All animals can move parts of their bodies. Many simple animals move with the help of microscopic hairlike structures called cilia. Another form of creeping movement, seen in earthworms, involves changes in body shape. Jointed limbs are found in only two groups of animals: the arthropods and vertebrates. Many animals can glide, but only insects, birds, and bats are capable of powered flight. Many forms of behavior help animals to survive severe environmental conditions. Two examples are hibernation, which enables animals to survive cold and food shortages in winter; and estivation, which allows animals to survive drought and heat in summer. Special forms of behavior also help animals to find food, to avoid being eaten, and to protect their young. One of the most advanced forms of this behavior is the use of tools. More rarely, some tool-using animals seek out a particular object and then shape it so that it can be used. Defensive behavior is exhibited by individual animals and also by animal groups. Group defense is common in herding mammals, which form a protective ring around their calves when threatened by wolves. Individual defensive behavior is often based on threatening gestures that make an animal look larger or more dangerous than it actually is. Sometimes it involves some highly specialized forms of deception. One of the most remarkable is playing dead.

  The text is headlined Animals. It was written by James Herriot. The article comes up from book « All Creatures Great And Small». The article was published 1972. It is situated on page 13-15. The article lies in biology. The article is do not supplied with a photograph of animals. Central topic of the article is variety of animals. The author lays stress on groups of animals, their similarities and differences, ability to adapt to different environmental conditions. The article opens in a description general characteristics of animals. After that, the author writes about the similarities and differences between animals that enable them to be classified into groups. Birds, for example, are the only animals that have feathers, while mammals are the only ones that have fur. Animals are also classified according to other characteristics, including their internal anatomy, patterns of development, and genetic makeup. Scientists divide the animal kingdom into approximately 30 groups, each called a phylum. In the closing paragraph the author tells us about the behaviors of animals that help them to survive severe environmental conditions. I find the article informative and attention-catching. The author correctly wrote about the behavior, nutrition, lifestyle, ways of animal locomotion, and I can`t agree more. The article is aimed to acquaint the readers with a variety of animals. The article is intended for a wide range of readers.