Weather,climate and adaptation in animals all question answers | CLASS 7 SCIENCE , CHAPTER 7

1. Name the 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 conditions 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 such as temperature ,food and water.

4. What is global warming?

Ans: The rise in Earth’s temperature due to increase of greenhouse gases like carbon dioxide , nitrous oxide etc is called global warming.

5. Name two greenhouse gases.

Ans: Carbon monoxide and Methane .

6. What is camouflage?

Ans: An adaptation in animals that helps them appear as a part of their natural surroundings is called camouflage.

7. Describe the climate in the polar regions.

Ans: The polar regions have very low temperature and little sunlight and are covered with ice throughout the year.

8. How does desert fox survive in the desert?

Ans: Desert fox survives in the deserts by obtaining water from the animals it eats thus living without drinking water.

III. 1. Differentiate between weather and climate

Ans:  Weather : 

• It refers to the day to day conditions of the atmosphere at a place .
• Weather conditions change very frequently.

         Climate  : 

• Average weather conditions prevalent in a region over a long period of time (25-30) years is called climate of the region.
• Climate conditions changes over a long period.

2. Why are regions so closed to the equator warm?

Ans: As the sun remains overhead throughout the year at the equator , the regions closed to the equator receives direct sunlight thus absorbing more heat and making the regions warmer.

3. Describe the climate of a tropical rainforest.

Ans: Tropical rainforest have a warm humid climate and receives plenty of rainfall throughout the year . The rich variety of animals living  in tropical forest are adapted to live in warm and wet conditions.

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

Ans: Many kinds of broad leafy trees grow in tropical rainforest . Trees grow close to each other and form a thick overhead covering called a canopy that blocks the sunlight from reaching the forest floor. As a result  ferns , variety palms and other plants that require little sunlight grows on the forest floor.

5. List two adaptations that makes penguins good swimmers .

Ans: Due to the adaptations of their webbed feet and streamline body penguins are excellent swimmers.

IV. 1. Why do different regions have different climate ?

Ans: The temperatures of different regions  on the earth vary .

                    The regions close to the equator receives direct sunrays thus absorbing more heat and making the regions warmer maintaining a temperature of above 50°C in the desert regions of Africa.

                     At the polar regions they receive very little sunlight and are covered with ice throughout the year as  the heat is reflected away by the white ice -covered surface. Here, temperature falls to -80°C.

                     Lastly , the temperate regions receive moderate amount of heat and light from the sun thus having moderate climate ,which is neither too hot nor too cold.

2. How is the polar bear adapted to live in the Artic region ?

Ans: The adaptations seen in the polar bear living in the Artic region are as follows-

• The thick layer of fat called blubber and the two seperate layers of fur – undercoat and outer   layer keeps the polar bears warm even at temperature below  -30°C.
• The outer layer of fur being hollow traps air keeping the body warm ,being waterproof protects the bear from water and ice crystals  and lastly being transparent it helps in camouflage.
• When temperature gets terribly cold they sleep for 8 hours everyday thus reducing the intake of food. This habit also helps the polar bear survive in the Artic region.

3.  How do desert animals conserve water ?

Ans: Desert animals show several ways in conserving water . Some animals live in burrows during the day and only emerges at night for food . The kidneys of desert animals concentrate urine , so they lose little water .Some animals also show different adaptations in their body such as camels which helps them maintain their body temperature without sweating even if the temperature  rises.

        In these ways desert animals conserve water.

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

• migration
• camouflage

Ans:   Migration is defined as the movement of animals at certain times of the year or during a phase of their life cycle.

                 Migration helps birds and animals in search of more favourable conditions such as temperature ,food and water.  Eg- BIrds , butterflies , turtles ,salmon fish etc.

         Camouflage is defined as an adaptation that helps them appear as a part of their natural surroundings.

             This adaptations help animals avoid predators and increase its ability to  survive . Eg- Polar bear.