Class 6/Practice Questions
Created by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
Created by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
Practice questions testing deep understanding of leaf structure, photosynthesis, and modifications.
Test your knowledge of the leaf with these advanced, application-based questions.
Read the following scenario and answer the questions: Scenario: A student covered a green leaf of a healthy potted plant with a piece of black paper. After keeping the plant in sunlight for a few days, they plucked the leaf, removed the paper, and tested it for starch using iodine solution. The covered part remained pale, while the uncovered part turned blue-black.
Q1. Explain the biological reason why the covered part of the leaf did not turn blue-black when tested with iodine.
Q2. If the student had covered the entire plant with a clear, transparent plastic bag instead of black paper, what would be the result of the starch test? Justify your answer.
Q3. Look at the microscopic structure of a leaf's lower surface. There are numerous tiny pores surrounded by bean-shaped cells. What would happen to the plant if these pores were permanently blocked by a layer of thick wax?
Q4. Cactus plants live in deserts and often lack typical broad leaves. Instead, they have spines. Explain how this modification helps the plant survive and how it manages to perform photosynthesis without normal leaves.
Directions: For the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Choose the correct option: (a) Both A and R are 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.
Q5. Assertion (A): The upper surface of a leaf is generally greener and shinier than the lower surface. Reason (R): The upper surface faces the sun and contains a higher concentration of chloroplasts to maximize photosynthesis, and is often covered by a waxy cuticle.
Q6. Assertion (A): Pitcher plants are carnivorous and trap insects. Reason (R): Pitcher plants cannot perform photosynthesis and rely entirely on insects for energy.
Q7. In a dense forest, the leaves of trees in the uppermost canopy are often smaller and thicker, while the leaves of plants growing on the forest floor are very large and thin. Analyze the biological reasoning behind these two different leaf adaptations.
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