|
|
Animals
More than a million different kinds of animals inhabit the Earth.
The exact number is not known, for new kinds are continually being
discovered. They live in the seas, from the surface down to the black
depths where no ray of light penetrates. On mountaintops and in deserts,
in mud and in hot pools some form of animal life may be found.
Animals are infinitely varied in form, size, and habits.
The smallest animals are bits of protoplasm that can be seen only with
a microscope. The largest, the blue whales, may be more than 100 feet
(30 meters) long and weigh 300,000 pounds (136,000 kilograms).
Animals are classified into amphibians, birds, fish, mammals, and
reptiles. Some animals are kept by humans as pets for companionship or for the beauty of its appearance or utterances.
|
Amphibians hatch from eggs as tadpoles and live both in and out of
water. They usually stay near water, and have soft, moist skin.
Amphibians are a class of tetrapod vertebrates, which are a link between
fishes and the true land-living vertebrates like reptiles, birds and
mammals.
Examples: frogs, newts, salamanders.
|
Birds lay eggs, and have feathers. They are descended from dinosaurs.
Birds (Class Aves) are warm-blooded egg-laying vertebrates characterized
by feathers and forelimbs modified as wings. There are almost 9000
known species of birds in the world.
|
Fish live under water, have gills for breathing, and lay many eggs.
Fishes is the proper English plural form of "fish" that biologists use
when speaking about two of more fish species. There are over 25,000
fishes in the world (meaning that there are over 25,000 fish species in
the world). When speaking of many fish that all are part of the same
species, then the word "fish" is used.
There are several million fish in the species Gadus morhua.
|
|
Mammals are warm-blooded; the young are born alive (i.e. not from eggs,
except for the duck-billed platypus and the echidna).
They feed on mother's milk. They have fur or hair or quills.
Examples: Dolphins, Elephants, Horses, Pandas, Cats, Dogs.
|
Reptiles spend most of their time on land and lay soft-shelled eggs.
The young look like small adults.
Examples: alligators, snakes.
|
Animals (Kingdom Animalia) comprise one of the five kingdoms of living organisms and are characterized as being multicellular creatures who are able to sense their surroundings and respond to them through voluntary motion. Along with other lifeforms, animals are a part of the domain Eukaryota. Colloquially, the term "animal" is often used in the narrower sense of non-human animals.
|
Nature refers to the material world and its phenomena;
those things which exist in reality as part of the
universe, and are not artificial, or imagined.
In scale, 'nature' includes everything from the universal to the
subatomic. This includes all things animal, plant, and mineral,
as well as events (hurricanes, tornadoes, earthquakes).
It also includes the behaviour of living animals, and the processes
associated with inanimate objects.
Life is the physical state perpetuated by functional systems through
which an organism obtains energy, grows and reproduces itself.
Life as we know it probably first arose on Earth about three to four
thousand million years ago.
About Animals
|
|
Life
