Exercise

II. Answer the following questions in one sentence.

1. Name the major climatic zones of the earth.

Ans. The major climatic zones of the earth are ––– tropical, temperate and polar.

2. What is weather?

Ans. Weather refers to the day to day condition of the atmosphere at a place with respect to temperature, humidity, sunlight, wind speed and rainfall.

3. Why do birds migrate?

Ans. Birds migrate in search of more favourable conditions. Birds live in cold regions fly away to warmer regions when the weather turns extremely cold in winter.

4. What is global warming?

Ans. Human actions have increased the amount of greenhouse gases. As a result, Mohit is being tracked and this has increased the Earth's temperature. This is known as a global warming.

5. Name any two greenhouse gases.

Ans. Methane and carbon dioxide.

6. What is camouflage?

Ans. Camouflage is an adaptation in animals that helps to appear as a part of their natural surroundings.

7. Describe the climate in the polar regions.

Ans. The polar regions receive slanted sun rays and less heat. Most of the heat is reflected by the white ice covid surface. Therefore the polar regions are very cold.

8. How does the desert fox survive in the desert?

Ans. Due to the scarcity of water in desert it is difficult for animals to survive in the the desert. The desert fox obtains water from the animals it eats and can live without drinking water.

III. Answer the following questions in two sentences.

1. Differentiate between weather and climate.

Ans. Weather: It is the day to day condition of the atmosphere. It can change frequently even within a few hours in a day.

Climate: It is the average weather condition of a region over a long period of time. It does not change frequently.

2. Why are regions close to the equator warm?

Ans: The regions close to the equator receive direct sun rays. Hence the earth absorbs more heat than it loses. That is why regions close to the equator are warm.

3. Describe the climate of a tropical rainforest.

Ans: Forest in the tropical regions have a warm humid climate with plenty of sunlight and rainfall. The summer months are very hot and winter months are not very cold. 

4. What type of plants grow on the forest floor in a tropical rainforest? Why?

Ans. In a tropical rainforest the thick overhead covering called a canopy that blocks the sunlight from reaching the forest floor. As a result, only ferns, some variety of palms and other plants that require little sunlight grow on the forest floor.

5. List two adaptations that make Penguins good swimmers.

Ans. The following adaptations make the Penguins good swimmers.

     i. Streamlined body.

    ii. Webbed feet. 

IV. Answer the following questions in about four to five sentences. 

1. Why do different regions have different climate?

Ans. Different regions have different climate because the different regions receive different amount of sunrays.

The regions near to the equator receive direct sunrays i.e. the sunrays fall perpendicularly in these regions. As a result the temperature in these regions is comparatively more. 

On the other hand the polar regions receive slanted sunrays and less heat. Besides the white ice covered surface reflect the sunrays. As a result the temperature in this region is comparatively less.

Similarly the region between the tropic of cancer and arctic circle along with the region between the tropic of Capricorn and Antarctic circle receive moderate amount of light and heat. 

Based on the above discussion it can be concluded that the different climate in different regions is seen because of the geographical location of a particular region.

2. How is the polar bear adapted to live in the Arctic regions?

Ans.  Polar bear is perfectly adapted to live in extremely cold Arctic region. 

They have two layers of fur and thick layer of fat called blubber to keep their body warm. The outer layer of fur is made up of long, transparent, hollow and waterproof hairs to protect them from coldness and water and ice crystals. The white fur helps in camouflage.  The sharp sense of smell helps to locate food. In winter, the region becomes extremely cold, and food becomes scarce. So it sleeps for longer time to reduce food intake.

3. How do desert animals conserve water?

Ans. The availability of food and water is extremely less. So the desert animals are adapted to live with very less water.  They can conserve water in many ways. Most of the desert animals live in burrows during the day which do not get too cold or too hot. This helps them to conserve water. Besides most desert dwellers have light coloured skin to reflect back the heat waves. The kidneys of desert animals concentrate urine to reduce the loss of water.

4. How do the following adaptations help animals live in a particular condition?

  • migration
  • camouflage
Explain with an example.

Ans. Migration : Migration helps survival of animals. The birds loving polar region migrate to warmer region when the weather turns extremely cold. Similarly animals migrate from one place to another in search of food and water also to avoid harsh weather conditions. Besides some animals and fishes migrate for breeding purpose.

Camouflage: It is an adaptation of animals which protects them from being hunted by other animals. The body colour or the colour of fur of some animals is same as that of the surrounding. Because of this they are not properly visible to the hunter animals. The fur of polar bear appears white and this helps to hide themselves in the ice.