Frogs :: essays research papers fc

Frogs are needed for everyday life. They are part of pool life. Each animal is important because even in the pond, there is a food chain. Frogs are amphibians, animals that knock off half of their lives under piddle, and remainder on land. The first frog appeared in the early Jurassic period roughly 200 million years ago.Frogs live on every virtuous except Antarctica, but tropical regions have the largest amount. Like all amphibians, frogs spend half their lives near water because they must return to the water to nonplus their eggs. Frogs live underwater mostly when the are growing up to be an adult frog and when they are laying their eggs. When they hatch under water they are tadpoles and the breath with gills and swim using a tail. As they progress they loose their tail and they develop to be able to breathe air. During an ample period of heat, a drought, frogs can enter a period of damancy identical to hibernation called starvation. Most of the frogs live in tropical and semitropical regions, most species of frogs mental strain in the spring or in early summer. Although the different species my parti-color in size and color, mostly all frogs have basic personify structure. They have large hind legs, short front legs and flat headland and body with no neck.Most frogs have teeth only on their upper jaw. Toads swallow their prey in one piece. To aid in the swallowing process, the frogs eyes sink through the openings in the skull and forces the food down its throat. Frogs eat insects, catching them with their long sticky tongue. They excessively eat small fish and worms. They also absorb concentrate to install them stronger, and toxins (poisonous substances) in their fatty tissues.Since the 1980s scientists have noted the decline of umteen frog species. People do not know for certain what has caused these declines. A possible factor is defilement, disease, habitat destruction, and acid rain. Another factor may be the thinning of the earths prot ective ozone layer, which allows more destructive ultraviolet radiation from the sun to reach the earth. Because frogs have thin, moist shinny and an aquatic tadpole stage, they are easily affected by pollution and changes in the environment.