Mammals

A mammal is an endothermic, “warm-blooded”, animal whose body is “heated from inside” and stays much the same temperature, no matter how hot or cold the surroundings.

When a mammal’s body breaks down food and oxygen in order to build new tissue and to supply energy, heat is produced. Hair, which grows out of the mammal’s skin, and fat, which lies under it, help insulate the mammal’s body against heat loss.

If the mammal becomes too hot, it cools itself by sleeking down its hair, sweating, panting or moving to a cool place. If the mammal becomes too cold, goosebumps pull its hair erect, it shivers to make extra body heat, and moves to a warmer place.

Monotremes have a normal body temperature of 30 degrees C. Marsupials average 35 degrees C, while human (which is also a mammal) body temperature is normally about 37 degrees C.

Desert mammals often have big ears and rangy bodies. The large skin area loses heat fast.

Mammals which live in cold places have compact bodies and thick fur. Insulating fat beneath their skin can be used by the body as a food source in very cold weather.

Some animals, like small bats and echidnas, survive cold by going into a short-term resting state called torpor, or a longer “sleep” called hibernation.

2.13 Answer the questions:

1. Why is a mammal an endothermic animal?

2. How is heat produced in the mammal’s body?

3. What does the mammal do if it’s too hot or too cold?

4. Is the body temperature of monotremes different from that of marsupials?

5. Why do desert animals often have rangy bodies?

6. What kind of bodies do mammals living in cold places have?

7. Why do they insulate fat beneath their skins?

8. How do some animals survive in cold?

2.14 Translate the following words into Russian. Then complete the columns:

A B

Names of trees: Names of flowers:

Oak, rose, willow, daffodil, forget-me-not, elm, violet, lilac, daisy, orchid, buttercup, bluebell, fir, carnation, pine, poppy, dandelion, lily, birch, maple.

Date: 2015-04-23; view: 1381; Нарушение авторских прав