WHY DO ANIMALS HIBERNATE?
The word 'hibernate' comes from a Latin word which means 'winter sleep'. Not all animals in temperate
countries hibernate. Some, like the bear, the squirrel and the chipmunk do not really hibernate. They
do sleep more during the snowing season than in summer but on warm and pleasant days, they will
wake up and come out in the open.
A good example of a typical hibernating animal is the woodchuck. Unlike the squirrel, it does not have
to work extra hard during the summer months to collect and store food for the cold season. It depends
on plant food and when the season comes along; its food supply is gone. However, it has a reserve
supply of fat on its own body. Thus, when it can no longer find food, it crawls deep into its burrow and
goes to sleep. It sleeps through the whole season and lives on the fat which it has stored in its body.
The sleep of a true hibernator is almost like death. It is quite different from ordinary sleep. While an
animal is hibernating, all its body functions almost stop. The temperature of its body decreases rapidly
until it is only slightly higher than the surrounding air in its den. This allows the animal to burn the fatin
its body very, very slowly. Since it burns less fuel, less oxygen is released and the result is that its breathing
is slower and its heart beats only faintly. If the temperature in the den becomes very low, the hibernating
animal wakes up, digs itself a little deeper and goes to sleep once again.
The animal is awakened in spring by the change in temperature, moisture and hunger. It then crawls
out of its den.
It is interesting to know that many cold blooded animals hibernate too. Earthworms crawl down into
the earth below the frost line; frogs bury themselves in the mud at the bottom of ponds and snakes
crawl into cracks in the rocks or holes in the ground.
On the basis of your understanding of the passage, answer any eight of the following questions :
(a) When do animals hibernate?
(b) Why is the bear not a real hibernator?
(c) What does a squirrel do in summer?
(d) What does the woodchuck eat? Tant food
(e) Why does its food supply disappear in winter?
(f) What does it do when it cannot find food?
(g) What does true hibernating resemble?
(h) What does the word 'This'in paragraph 3 refer to?
(0) How does a hibernating animal know that spring has arrived?
Answers
Answer:
The word 'hibernate' comes from a Latin word which means 'winter sleep'. Not all animals in temperate
countries hibernate. Some, like the bear, the squirrel and the chipmunk do not really hibernate. They
do sleep more during the snowing season than in summer but on warm and pleasant days, they will
wake up and come out in the open.
A good example of a typical hibernating animal is the woodchuck. Unlike the squirrel, it does not have
to work extra hard during the summer months to collect and store food for the cold season. It depends
on plant food and when the season comes along; its food supply is gone. However, it has a reserve
supply of fat on its own body. Thus, when it can no longer find food, it crawls deep into its burrow and
goes to sleep. It sleeps through the whole season and lives on the fat which it has stored in its body.
The sleep of a true hibernator is almost like death. It is quite different from ordinary sleep. While an
animal is hibernating, all its body functions almost stop. The temperature of its body decreases rapidly
until it is only slightly higher than the surrounding air in its den. This allows the animal to burn the fatin
its body very, very slowly. Since it burns less fuel, less oxygen is released and the result is that its breathing
is slower and its heart beats only faintly. If the temperature in the den becomes very low, the hibernating
animal wakes up, digs itself a little deeper and goes to sleep once again.
The animal is awakened in spring by the change in temperature, moisture and hunger. It then crawls
out of its den.
It is interesting to know that many cold blooded animals hibernate too. Earthworms crawl down into
the earth below the frost line; frogs bury themselves in the mud at the bottom of ponds and snakes
crawl into cracks in the rocks or holes in the ground.
Answer:
When magnesium ribbon is exposed to air, it forms a layer of magnesium oxide on its surface. This layer of magnesium oxide, being a stable compound, prevents further reaction of magnesium with oxygen. Hence, it should be cleaned before burning in air to remove this layer so that the metal can be exposed to air properly.