Question 1: Define the term 'cuticle' as it relates to leaf structure.

Answer: The cuticle is a waxy, protective layer covering the surface of the leaf that reduces water loss.

Question 2: Explain the role of stomata in a leaf.

Answer: Stomata are small pores on the leaf surface that regulate gas exchange, allowing carbon dioxide in and oxygen out during photosynthesis.

Question 3: What is the primary function of chloroplasts within leaf cells?

Answer: Chloroplasts contain chlorophyll and are responsible for carrying out photosynthesis, converting light energy into chemical energy.

Question 4: Describe how the structure of a leaf's palisade mesophyll contributes to photosynthesis.

Answer: The palisade mesophyll consists of tightly packed, elongated cells rich in chloroplasts, positioned near the upper surface of the leaf to maximize light absorption for efficient photosynthesis.

Question 5: Calculate the surface area in square centimeters of a leaf measuring 12 cm by 8 cm.

Answer: 96

Question 6: Which component of the leaf primarily facilitates the exchange of gases during photosynthesis?

Answer: Stomata

Question 7: Fill in the blank: The _______ is the layer of cells inside the leaf that contains many chloroplasts and is the site of photosynthesis.

Answer: palisade mesophyll

Question 8: Why is the waxy cuticle important for terrestrial plants?

Answer: The waxy cuticle prevents excessive water loss from the leaf surface, helping plants conserve water in dry environments.

Question 9: Identify a practical experiment that could be conducted to observe the opening and closing of stomata in a leaf. Describe the main variables involved.

Answer: An experiment could involve observing leaf samples under a microscope in different light and humidity conditions. The independent variables are light intensity and humidity; the dependent variable is stomatal aperture; control variables include temperature and leaf type.

Question 10: A plant is kept in a dark environment for 48 hours. Predict and explain what will happen to the number of active stomata.

Answer: The number of active stomata will decrease because in darkness, photosynthesis slows down, reducing the need for gas exchange and water loss.

Question 11: Explain how leaf structure varies in plants adapted to dry environments compared to those in wet environments.

Answer: In dry environments, leaves often have a thick, waxy cuticle, fewer stomata, and may be reduced in size to minimize water loss. In contrast, leaves in wet environments tend to have a thinner cuticle and more stomata to facilitate gas exchange.