РефератыИностранный языкAnAnimal Species Essay Research Paper Living creatures

Animal Species Essay Research Paper Living creatures

Animal Species Essay, Research Paper


Living creatures on Earth need three basic things in order to survive: the


ability to eat, breath, and reproduce. All animals are able to do so. Animals


are divided into species, among these species are: Mammals, Reptiles,


Arthropods, and Aves. Mammals, also known as Mammalia, come from Latin meaning


mamma breast. They are called this due to the fact that Mammals are the only


animals which have mammary glands, which enable them to nourish their young


solely on milk secreted from these glands. Mammals are warm blooded, and all,


except for marine mammals, are mostly or completely covered with hair. Mammals


give birth to live young, however, there are a few rare exceptions to this rule.


A few mammals, such as the platypus, lay eggs instead of having live young. Yet


once the eggs are hatched the females do have mammary glands, and produce milk


for their young. Another feature of mammals is that their heart has four


chambers and a muscular diaphragm that separates their chest and abdominal


cavity. The mammal class includes: Dogs, cats, horses, beavers, dolphins, bats


and humans. Another animal species are Reptiles, also known as Reptil which is


Latin for Reptus, meaning to crawl. Reptiles are usually hairless with dry,


scaly skin. They are cold-blooded, which means in order for them to maintain a


stable body temperature, they must be exposed to some heat source, such as the


sun, or a rock warmed by the heat of the day. Due to the need for warmth,


Reptiles are naturally found in warm, dry climates. All reptiles, except for


snakes, have low slung bodies with long tails, balanced on four awkwardly small


limbs. Although there are a few aquatic Reptiles (Reptiles who live mainly in


water), they all must come up to the surface for oxygen. Reptiles do not give


birth to live young. Instead, they lay eggs on land. The female usually buries


the eggs in warm dirt or sand to incubate them. Reptiles do not have mammary


glands therefore, their young are not dependent on their mother for food and


soon after birth, they must learn to obtain food for themselves. The Reptile


class includes: turtles, alligators, snakes, lizards, and dinosaurs. The animal


species that makes up over eighty percent of all species are Arthropods.


Arthropod comes from the Latin word, Arthropoda, meaning foot. Arthropods tend


to have many legs and feet, giving purpose to their name. Arthropods are


invertebrate, which means they have no backbone. Unlike other animal species,


Arthropods have what is called an exoskeleton which is an external skeleton or


shell. The exoskeleton is jointed, allowing Arthropods to move, and as the they


grow, their exoskeleton sheds, or molts, and a new, larger one grows to replace


it. All Arthropods lay eggs and care for them, yet when they young are born,


they are immediately independent. The Arthropod class includes: insects,


spiders, centipedes, and crabs. A very beautiful, yet simply diverse animal


species are Aves. Aves, also known as Birds, are warm-blooded, egg-laying


animals. Aves are covered with feathers and its forelimbs are wings. Like


mammals, birds have a four-chambered heart; they have a relatively large brain


and acute hearing but little sense of smell. Aves are highly adapted for flight.


Their feathers, though light, protect against cold and wet and have great


strength. Aves are well known for their beautiful whistle, or song, yet the


singing ability is usually restricted to, or superior in, the male. Most birds


build some kind of nest for their eggs, which vary in size, shape, color, and


number according to species. Their young are cared for by the parents until they


reach maturity. The class of Aves include: geese, flamingos, humming birds, and


penguins. Each of these animal species are very unique and crucial to the Earth.


Without these diverse creatures, the world would not have the variety and beauty


it beholds today.

Сохранить в соц. сетях:
Обсуждение:
comments powered by Disqus

Название реферата: Animal Species Essay Research Paper Living creatures

Слов:704
Символов:4650
Размер:9.08 Кб.