Question 1: Define the term 'cuticle' in relation to leaf anatomy.

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

Question 2: Explain how the structure of the palisade mesophyll contributes to photosynthesis.

Answer: The palisade mesophyll consists of tightly packed, elongated cells rich in chloroplasts, maximizing light absorption for photosynthesis.

Question 3: What is the primary function of stomata in a leaf?

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

Question 1: A leaf's stomata are open for 8 hours in a day, resulting in a water loss of 0.5 grams per hour. Calculate the total water loss in grams over the day.

Answer: 4 grams

Question 2: If a leaf needs to absorb 200 ppm of CO2 for photosynthesis, how many milligrams of CO2 are required per liter of air? (Note: 1 ppm of CO2 equals approximately 1.96 mg per liter).

Answer: 392 mg

Question 1: Design a simple experiment to test how different levels of light affect stomatal opening in leaves. Include variables, controls, and safety precautions.

Answer: Students can use leaves exposed to varying light intensities (e.g., full sunlight, shade, darkness). The independent variable is light level; the dependent variable is stomatal opening (measured via microscopic observation). Controls include same leaf species and age. Safety precautions involve handling sharp tools carefully and avoiding prolonged exposure to direct sunlight to prevent burns.

Question 2: Identify two environmental variables that could affect leaf gas exchange during space cultivation experiments and explain how they might influence results.

Answer: Variables include humidity and temperature. High humidity may reduce transpiration rates, while extreme temperatures can impair stomatal function, both affecting gas exchange efficiency.

Question 1: In a space habitat, engineers have designed a leaf-like panel with a thick cuticle and reduced stomata to minimize water loss. What are potential advantages and disadvantages of this design for growing plants in space?

Answer: Advantages include reduced water loss and better water conservation in a closed environment. Disadvantages may involve decreased gas exchange, limiting photosynthesis and oxygen production, which could hinder plant growth and air quality.

Question 2: Describe how understanding leaf structure can help improve the design of plant cultivation systems for Mars habitats.

Answer: Knowledge of leaf anatomy allows engineers to optimize light absorption, water retention, and gas exchange. For example, designing leaves or panels with specific cuticle thickness and stomatal density can enhance plant efficiency, ensuring sustainable oxygen and food production in the harsh Martian environment.