Textbook Question and Answer.
Keywords:
- Streamlined: Broad in the middle and narrow at both ends, like a boat.
- Locomotor organs: Organs that help an animal move from one place to another.
- Tentacles: A slender, flexible limb.
- Tube feet: Small tube-like structures found on the underside of echinoderms.
- Hibernate: To go into a deep, sleep-like state during winter.
- Extinction: A situation in which a plant, an animal, or a way of life stops existing.
- Endangered: At risk of no longer existing or becoming extinct.
Q.1 Assertion and Reasoning Questions:
1. Assertion (A): Polar bears have thick fur and a layer of fat.
Reasoning (R): Polar bears live in hot deserts.
Ans: A is true, but R is false.
2. Assertion (A): Frogs can live both in water and on land.
Reasoning (R): Frogs have lungs and moist skin to breathe on land and in water.
Ans: Both A and R are true, and R is the correct explanation of A.
Answer the Following Questions:
Q.1 Why do polar bears show hibernation as an adaptation?
Ans: Polar bears show a form of hibernation as an adaptation to survive extreme cold winters, especially when food is hard to find.
Q.2 Why is camouflage important for animals?
Ans: It helps animals hide from enemies and helps predators catch prey.
Q.3 How are frogs adapted to live on land or in water?
Ans:
- i) Frogs breathe through their lungs and use their moist skin to breathe in water.
- ii) Frogs have a transparent third eyelid called a nictitating membrane; it prevents water from entering their eyes.
- iii) They have webbed feet that help them survive and swim in water.
Q.4 List the three types of feathers and their uses.
Ans:
- Flight feathers: Help the birds to fly.
- Soft down feathers: Keep the birds warm.
- Tail feathers: Help the bird control the direction of flight.
Q.5 Explain how aquatic animals are adapted to live in water.
Ans:
- (i) Most aquatic animals have a streamlined body, which helps them move quickly and easily in water.
- (ii) Fish breathe through gills.
- (iii) The soft bodies of fish are protected by scales.
Q.6 Describe any three adaptations of animals living in deserts.
Ans:
- (i) Camels have bushy eyebrows and two rows of eyelashes, which prevent sand from entering their eyes.
- (ii) They have humps to store fat.
- (iii) They have padded feet so that they can walk easily on sand without their feet sinking into it.
Q.7 A duck and a hen are asked to cross a pond. Which one will cross more easily?
Ans: The duck, because it has webbed feet and waterproof feathers that help it swim.
Q.8 Explain three adaptations of polar bears.
Ans:
- i) Thick white fur keeps them warm.
- ii) A thick layer of fat protects them from the cold.
- iii) White fur helps them blend in with the snow.