Keywords:
- Stimuli: Things or events that get a specific reaction from living things.
- Lifespan: The specific period of time for which a living thing lives.
- Aquatic animals: Animals that live in water.
- Spiracles: Tiny holes on the body of insects used for breathing.
- Photosynthesis: The process by which plants prepare food.
- Producers: Plants that prepare their own food are called producers.
- Consumers: Animals that cannot prepare their own food are called consumers.
Q.1] Assertion and Reasoning Questions
1. Assertion: Roots absorb water from the soil.
Reasoning: Roots fix the plant to the ground.
a] A and R are both true, and R is the correct explanation of A.
b] Both A and R are true, but R is not the correct explanation of A.
c] A is true, but R is false.
d] A is false, but R is true.
Ans: b] Both A and R are true, but R is not the correct explanation of A.
2. Assertion: Kangaroos primarily move by hopping using their powerful hind legs.
Reasoning: These two hind legs allow them to cover large distances quickly and efficiently.
Ans: a] Both A and R are true, and R is the correct explanation of A.
Q.2] Answer the Following
1. Why do animals move from one place to another?
Ans: Animals move from one place to another in search of food, water, and shelter, and also to protect themselves from their enemies.
2. Insects like ants are tiny and don’t have lungs. How do they breathe?
Ans: Insects breathe through tiny holes in their body called spiracles. Air goes through tubes inside their body.
3. The cheetah is the fastest land animal. Which body parts help it run fast?
Ans: The cheetah has long, strong legs and a flexible spine. Its long legs take big strides, and the spine stretches to cover more distance.
4. Why does the touch-me-not plant fold its leaves when touched?
Ans: It folds its leaves as a defense mechanism to protect itself from animals that might eat it or from damage.
5. How are plants classified on the basis of their lifespan?
Ans: Based on their lifespan, plants are classified into three types:
- (i) Annual plants: Have a lifespan of one year. (e.g., Pea plant)
- (ii) Biennial plants: Have a lifespan of two years. (e.g., Sugar beet)
- (iii) Perennial plants: Have a lifespan of more than two years. (e.g., Hibiscus)
6. What is reproduction? How do you differentiate between viviparous and oviparous animals?
Ans:
- i) Reproduction is the process by which living things produce young ones of their own kind.
- ii) Animals that lay eggs to reproduce are called oviparous animals. (e.g., Birds, reptiles, insects, and fish)
- iii) Animals that give birth to their young ones are called viviparous animals. (e.g., Cows, humans, etc.)
7. Write the differences between plants and animals.
| Plants | Animals |
| I. Most plants prepare their own food. | I. Animals cannot prepare their own food. |
| II. Plants grow throughout their lives. | II. Animals grow until they reach a certain size, after which they stop. |
| III. Plants are fixed to the ground, but their parts can move. | III. Animals can move from one place to another. |
| IV. Most plants reproduce through seeds. | IV. Animals reproduce by laying eggs or by giving birth to young ones. |
| V. Plants breathe through stomata. | V. Different animals breathe through different organs such as the nose, lungs, gills, skin, etc. |
Breathing in Different Animals
| Animal | Breathing Organ | How it Works |
| 1. Humans | Lungs | Air goes through the nose; lungs take oxygen from the air. |
| 2. Fish | Gills | Gills take in oxygen dissolved in water. |
| 3. Frog | Skin and lungs | In water -> skin; on land -> lungs. |
| 4. Earthworm | Skin | Oxygen from the soil passes through their moist skin. |
| 5. Birds | Lungs, air sacs | Air enters through nostrils into air sacs, then it moves into the lungs. |
| 6. Insects | Spiracles (tiny holes) | Air enters through spiracles and moves through tubes inside the body. |
| 7. Whales & Dolphins | Lungs | Come to the water’s surface to breathe air. |
Animals and the Body Parts That Help Them Move
| Animal | Body Part | How it Helps |
| 1. Fish | Fins and tail | Fins keep balance; the tail pushes water backward. |
| 2. Birds | Wings | Wings flap to push air down, lifting the bird. |
| 3. Snake | Body & scales | Long, flexible body and scales. |
| 4. Earthworm | Muscles & bristles | Muscles contract, and bristles grip the ground. |
| 5. Cheetah | Long legs & flexible spine | Long legs take big strides; the spine stretches to cover more distance. |
| 6. Kangaroo | Strong hind legs & thick tail | Hind legs help to jump. |
| 7. Cockroach | Six legs | Jointed legs let it run fast. |
| 8. Frog | Hind legs | Hind legs push off the ground for jumping. |
Case-Based Question
Riya kept a potted plant inside a dark cupboard for 5 days. When she took it out, the leaves looked pale yellow.
Q.1) Why did the leaves turn pale yellow?
Ans: The plant did not get sunlight, so it could not make food.
Q.2) Which component of photosynthesis was missing?
Ans: Sunlight.
Q.3) What should Riya do to make the plant green again?
Ans: Keep the plant in sunlight.