Textbook Questions and Answers
Keywords:
- Habitat: The place where a plant or animal lives.
- Epiphytes: Plants that grow on other trees.
- Coniferous trees: Trees that produce cones.
- Cones: Hard, dry fruits produced by some trees growing in hilly regions.
- Structural adaptation: A change in the physical features of a plant to survive in its habitat.
- Xerophytes: Desert plants.
Q.1. Assertion and Reasoning Questions:
1. Assertion (A): Aquatic plants have waxy leaves.
Reasoning (R): A waxy coating prevents leaves from getting wet and damaged.
Ans: Both A and R are true, and R is the correct explanation of A.
2. Assertion (A): All plants can grow in any place with enough water.
Reasoning (R): Plants need specific adaptations to survive in their habitat.
Ans: A is false, but R is true.
Answer the Following Questions:
1. What does adaptation mean?
Ans: Adaptation is a special feature developed by a plant or an animal to live in a particular place or habitat.
2. Why can a cactus survive in the desert but a lotus cannot?
Ans: A cactus is adapted to desert conditions with thick stems to store water and spines to reduce water loss. A lotus is an aquatic plant and needs water to survive, so it cannot live in dry desert conditions.
3. A plant is found bending easily with water currents. What type of plant is it and why?
Ans: It is an underwater plant. It has a flexible stem, so it can move with water currents without breaking.
4. Imagine a plant growing in a very cold region. What adaptations will it have?
Ans: It will have needle-like leaves to reduce water loss, thick bark to protect from the cold, and a conical shape to allow snow to slide off.
5. How do mangrove roots help the plants survive in marshy areas?
Ans: The roots of mangrove plants grow above the soil to absorb gases directly from the air and spread widely to give support.
6. Which features help plants survive in windy areas?
Ans: The features that help plants survive in windy areas are a short height, a strong and flexible stem, and small or narrow leaves.
7. Write the differences between deciduous plants and evergreen plants.
| Deciduous Plants | Evergreen Plants |
| (i) Plants shed their leaves during autumn. | (i) Plants do not shed all their leaves at once. |
| (ii) Remain leafless for some time. | (ii) Remain green throughout the year. |
| (iii) Peepal tree, Banyan tree. | (iii) Coconut tree, Pine tree. |
8. What are the three main types of aquatic plants?
Ans: There are three types of aquatic plants:
- (i) Floating plants: Plants that float on the surface of the water and move along with the water flow are called floating plants. (e.g., Water hyacinth)
- (ii) Fixed plants: The roots of these plants are fixed to the mud at the bottom, and their leaves and flowers float on the surface of the water. (e.g., Lotus)
- (iii) Underwater plants: Plants that grow completely underwater are called underwater plants. (e.g., Hydrilla)
9. What are the special features of fixed plants?
Ans:
- i) The roots of fixed plants are fixed to the soil at the bottom of the water body.
- ii) They have light and hollow stems to help the leaves float.
- iii) The leaves have stomata on the upper surface for the exchange of gases.
- iv) The leaves have long, slender stalks.
- v) The leaves have a waxy surface; this keeps the leaves dry and protects them from decay.