Understanding Photosynthesis

What are the main products of the light-dependent reactions?

• NADH, water, and glucose

• Oxygen, carbon dioxide, and glucose

• ATP, NADPH, and oxygen

• Glucose, ATP, and carbon dioxide

How does chlorophyll absorb light energy?

• Chlorophyll absorbs light energy by exciting electrons in its pigment molecules when photons are absorbed.

• Chlorophyll absorbs light energy through a process of photosynthesis without any electron excitation.

• Chlorophyll absorbs light energy by converting it into heat.

• Chlorophyll absorbs light energy by reflecting photons away from the plant.

What role does water play in the light-dependent reactions?

• Water is a waste product of the light-dependent reactions.

• Water acts as a catalyst for the Calvin cycle.

• Water absorbs sunlight to produce glucose.

• Water provides electrons and protons, and produces oxygen during the light-dependent reactions.

Which wavelengths of light are most effective for photosynthesis?

• Infrared (700-800 nm) wavelengths of light

• Blue (430-450 nm) and red (640-680 nm) wavelengths of light are most effective for photosynthesis.

• Green (500-550 nm) wavelengths of light

• Yellow (570-590 nm) wavelengths of light

How do temperature changes affect the rate of photosynthesis?

• Temperature changes have no effect on photosynthesis.

• Lower temperatures always increase the rate of photosynthesis.

• Temperature changes affect the rate of photosynthesis by influencing enzyme activity, increasing it up to an optimum point and decreasing it beyond that.

• Photosynthesis occurs only at high temperatures.

What is the significance of NADPH in photosynthesis?

• NADPH is a byproduct of the Calvin cycle.

• NADPH is used to absorb sunlight during photosynthesis.

• NADPH is involved in the transport of oxygen in plants.

• NADPH is significant in photosynthesis as it provides the reducing power for the synthesis of glucose.

How does the concentration of carbon dioxide influence photosynthesis?

• Higher carbon dioxide levels reduce the rate of photosynthesis.

• Photosynthesis is unaffected by carbon dioxide concentration.

• Lower concentrations of carbon dioxide increase the rate of photosynthesis.

• Higher concentrations of carbon dioxide enhance the rate of photosynthesis up to a saturation point.

What is the function of the thylakoid membrane in chloroplasts?

• The thylakoid membrane is involved in cellular respiration.

• The thylakoid membrane facilitates the light-dependent reactions of photosynthesis.

• The thylakoid membrane stores glucose for energy.

• The thylakoid membrane absorbs nutrients from the soil.

How do light intensity and duration impact photosynthesis?

• Higher light intensity reduces the need for water in photosynthesis.

• Higher light intensity and longer duration increase the rate of photosynthesis.

• Lower light intensity decreases the rate of photosynthesis.

• Longer duration of low light has no effect on photosynthesis.

How do stomata regulate gas exchange in plants?

• Stomata allow water to escape while preventing carbon dioxide from entering.

• Stomata open and close to regulate the exchange of oxygen and carbon dioxide.

• Stomata are responsible for the absorption of nutrients from the soil.

• Stomata have no significant role in gas exchange.