Photosynthesis ceases when leaves wilt, mainly because a. the chlorophyll in wilting leaves is degraded. b. accumulation of CO2 in the leaf inhibits enzymes. c. stomata close, preventing CO2 from entering the leaf. d. photolysis, the water-splitting step of photosynthesis, cannot occur when there is a water deficiency.

Verified step by step guidance

1. Identify the main process affected in wilting leaves: Photosynthesis is a process that depends on the availability of CO2, light, and water to produce glucose and oxygen.
2. Analyze the options related to the availability of resources: In wilting, the primary concern is the loss of water, which affects various sub-processes of photosynthesis.
3. Focus on stomatal function: Stomata are the pores on leaf surfaces that allow for gas exchange (CO2 in, O2 out). When leaves wilt, these stomata close to prevent further water loss.
4. Link stomatal closure to CO2 availability: With the stomata closed, CO2 cannot enter the leaves, which is crucial for the Calvin cycle, a light-independent part of photosynthesis where sugar is synthesized.
5. Conclude the correct answer: Since the closure of stomata directly stops CO2 from entering, it inhibits the photosynthesis process. Therefore, the correct answer is c. stomata close, preventing CO2 from entering the leaf.

Key Concepts

Photosynthesis

Photosynthesis is the biochemical process by which green plants, algae, and some bacteria convert light energy into chemical energy, using carbon dioxide and water to produce glucose and oxygen. This process primarily occurs in the chloroplasts of plant cells, where chlorophyll captures sunlight. Understanding photosynthesis is crucial for grasping how plants generate energy and oxygen, which are vital for life on Earth.

Stomata

Stomata are small openings on the surfaces of leaves that regulate gas exchange, allowing carbon dioxide to enter and oxygen to exit. They play a critical role in photosynthesis and transpiration. When leaves wilt due to water deficiency, stomata close to conserve water, which limits CO2 intake and subsequently halts photosynthesis, illustrating the importance of water availability for plant function.

Photolysis

Photolysis is the process by which water molecules are split into oxygen, protons, and electrons using light energy during the light-dependent reactions of photosynthesis. This reaction is essential for providing the electrons needed for the electron transport chain, which ultimately leads to the production of ATP and NADPH. A deficiency in water disrupts photolysis, thereby impeding the entire photosynthetic process.