Question

Which of the following is required for photosynthesis? (a) \(\mathrm{CO}\), (b) Chlorophyll (c) Light (d) All of these

Short answer

The correct answer is (d) All of these. Each option (Carbon Dioxide (CO), Chlorophyll, and Light) is necessary for the process of photosynthesis to occur.

Step-by-step solution

Evaluate Option (a)

Carbon Dioxide (CO) is a necessary input for the photosynthesis process. In the leaves of a plant, carbon dioxide is absorbed from the air and is used to produce glucose, which is a type of sugar that plants use for energy.

Evaluate Option (b)

Chlorophyll, a pigment found in the chloroplasts of plant cells, is crucial for photosynthesis. It allows plants to absorb the light energy from the Sun that is required for the photosynthesis process.

Evaluate Option (c)

Light, especially from the Sun, is used in the process of photosynthesis. The chlorophyll inside the plant's cells absorbs light and uses its energy to combine carbon dioxide and water to produce glucose and oxygen.

Evaluate Option (d)

Option (d) indicates 'All of These.' Considering the previous evaluations, Carbon Dioxide (CO), Chlorophyll, and Light are all necessary for the process of photosynthesis. Hence, this option is correct.

Key concepts

Carbon Dioxide in Photosynthesis

Carbon dioxide (CO₂) plays a pivotal role in the process of photosynthesis, serving as a critical ingredient in the production of glucose. This colorless gas is absorbed by plants through small openings in their leaves called stomata. Inside the plant cells, CO₂ combines with water (H₂O), driven by energy harvested from sunlight, to produce glucose (C₆H₁₂O₆) and oxygen (O₂). This process is fundamental to the plant's growth and energy supply, also contributing to the Earth's oxygen levels.

• Carbon dioxide enters the leaves through stomata.
• It reacts in the chloroplasts with water.
• The product of this reaction is glucose, vital for the plant’s survival.

Chlorophyll Function

Chlorophyll, the green pigment found in chloroplasts of plant cells, is essential for capturing light energy from the sun. Its main role is to absorb light, primarily in the blue and red wavelengths, and convert it into chemical energy through a series of reactions known as the light-dependent reactions. This chemical energy is then used in the synthesis of glucose from carbon dioxide and water during the Calvin cycle, which occurs in the stroma of the chloroplasts.

• Chlorophyll captures solar energy.
• It energizes electrons, starting the process of synthesizing ATP and NADPH.
• The energy provided by chlorophyll is crucial for the Calvin cycle to produce glucose.

Light Dependence in Photosynthesis

Light is indispensable in the process of photosynthesis, which can be clearly understood when exploring its two main stages: the light-dependent and the light-independent reactions. In the light-dependent reactions, chlorophyll absorbs sunlight to generate ATP and NADPH, energy-rich compounds that are further used in the Calvin cycle. This cycle doesn't require light directly but depends on the energy supplied by ATP and NADPH from the initial stage.

Light-Dependent Reactions:

• Occur in the thylakoids of chloroplasts.
• Convert light energy into chemical energy (ATP and NADPH).

Light-Independent Reactions:

• Also known as the Calvin cycle.
• Use the chemical energy to convert CO₂ into glucose.