Unit Test Solutions: Adaptations in Plants

Total Marks: 20
Attempt all questions.

• Question numbers 1 to 8 carry 1 mark each.
• Question numbers 9 to 11 carry 2 marks each.
• Question numbers 12 & 13 carry 3 marks each.

Q1: What is a habitat? (1 Mark)
Ans: A habitat is the place where an organism lives and grows in nature.

Q2: Which of these is a floating plant? (1 Mark)
a) Hydrilla
b) Lotus
c) Duckweed
d) Pine
Ans: c) Duckweed

Q3: What helps desert plants reduce water loss? (1 Mark)
Ans: Reduced leaves or spines help desert plants reduce water loss.

Q4: Name any one deciduous tree found in plains. (1 Mark)
Ans: Cherry.

Q5: Which plants have aerial roots? (1 Mark)
Ans: Mangrove plants.

Q6: What type of leaves do mountain plants have? (1 Mark)
Ans: Needle-like leaves.

Q7: Which scientist wrote "On the Origin of Species"? (1 Mark)
Ans: Charles Darwin.

Q8: What percentage of Earth is covered by water? (1 Mark)
Ans: About 71%.

Q9: Why do plants need to adapt? (2 Marks)
Ans: Plants need to adapt to survive harsh climates and other unfavourable conditions. Adaptations help them stay safe, get food, and live in their habitat.

Q10: Write two features of fixed aquatic plants. (2 Marks)
Ans:

1. Their roots are fixed at the bottom of water bodies.
2. Their broad leaves float on water and have a waxy layer to keep them dry.

Q11: How do cactus plants survive in deserts? (Any two points) (2 Marks)
Ans:

1. They store water in their thick stems.
2. They have spines instead of leaves to prevent water loss.

Q12: Describe the adaptations of underwater plants with examples. (3 Marks)
Ans: Underwater plants stay submerged and have thin or ribbon-like leaves that bend with water currents. Examples include Hydrilla and Vallisneria. They do photosynthesis underwater and release oxygen for aquatic animals.

Q13: Explain how plants in mountains are adapted to survive cold and snowy conditions. (3 Marks)
Ans: Mountain plants are tall and cone-shaped so snow can slide off. They have needle-like leaves with waxy coatings to reduce water loss. Their drooping branches help shed snow and prevent breakage. Examples include pine, fir, and deodar.