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. Understand the process of photosynthesis: Photosynthesis is the process by which green plants use sunlight to synthesize foods with the help of chlorophyll. It involves the intake of carbon dioxide (CO2) and water (H2O), and the release of oxygen (O2).
2. Recognize the role of stomata: Stomata are small openings on the surface of leaves that allow for gas exchange. They play a crucial role in photosynthesis by allowing CO2 to enter the leaf.
3. Consider the impact of wilting on stomata: When leaves wilt, it is often due to a lack of water. This causes the stomata to close to conserve water, which in turn prevents CO2 from entering the leaf.
4. Evaluate the options given: Analyze each option to determine which one directly relates to the closure of stomata and the prevention of CO2 entry. Option c states that stomata close, preventing CO2 from entering the leaf, which directly impacts photosynthesis.
5. Conclude the reasoning: Since CO2 is essential for photosynthesis, the closure of stomata due to wilting leads to a cessation of photosynthesis because the plant cannot take in the necessary CO2.

Key Concepts

Photosynthesis

Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy stored in glucose. It involves two main stages: the light-dependent reactions and the Calvin cycle. The process requires chlorophyll, water, and carbon dioxide, and produces oxygen as a byproduct.

Stomata Function

Stomata are small openings on the surface of leaves that regulate gas exchange. They allow CO2 to enter the leaf for photosynthesis and release oxygen as a byproduct. When leaves wilt, stomata close to conserve water, which prevents CO2 from entering, thus halting photosynthesis.

Water's Role in Photosynthesis

Water is crucial for photosynthesis, particularly in the light-dependent reactions where it is split into oxygen, protons, and electrons during photolysis. A deficiency in water can impede this process, affecting the plant's ability to produce energy and leading to wilting and cessation of photosynthesis.