Photosynthesis Grade 12

What is the primary function of the light-dependent reactions in photosynthesis?

• Regulate the temperature of the plant

• Convert light energy into chemical energy

• Produce oxygen as a byproduct

• Generate glucose directly from sunlight

Which molecules are produced as a result of the light-dependent reactions?

• ADP and NADP+

• ATP and NADPH

• Glucose and Oxygen

• Carbon Dioxide and Water

What is the role of chlorophyll in the light-dependent reactions?

• Chlorophyll absorbs light energy and converts it into chemical energy.

• Chlorophyll stores excess light energy for later use in the light-dependent reactions.

• Chlorophyll breaks down water molecules to produce glucose in the light-dependent reactions.

• Chlorophyll releases oxygen into the atmosphere during the light-dependent reactions.

Explain the process of photolysis in the light-dependent reactions.

• Photolysis involves the breakdown of glucose into oxygen, protons, and electrons.

• Chlorophyll absorbs water and releases oxygen, carbon dioxide, and electrons.

• Light energy is used to convert carbon dioxide into glucose, water, and protons.

• Light energy is absorbed by chlorophyll, which splits water into oxygen, protons, and electrons.

What is the Calvin cycle and where does it take place in the chloroplast?

• The Calvin cycle takes place in the stroma of the chloroplast.

• The Calvin cycle takes place in the vacuole of the chloroplast.

• The Calvin cycle happens in the cytoplasm of the chloroplast.

• The Calvin cycle occurs in the thylakoid membrane of the chloroplast.

What are the three main steps of the Calvin cycle?

• Carbon fixation, reduction phase, regeneration of RuBP

• Photosynthesis, respiration, transpiration

• Carbon fixation, oxidation phase, regeneration of RuBP

• Light reaction, dark reaction, photorespiration

How is carbon dioxide converted into glucose during the Calvin cycle?

• Through a direct conversion process without any intermediate steps

• By using oxygen as a catalyst to speed up the reaction

• Through a single-step reaction involving only one enzyme

• Through a series of reactions involving RuBisCO and multiple steps including carbon fixation, reduction, and regeneration of RuBP.

What factors can affect the rate of photosynthesis?

• Soil pH, wind speed, humidity

• Nitrogen concentration, cloud cover, soil type

• Altitude, precipitation, time of day

• Light intensity, carbon dioxide concentration, temperature, water availability

How does temperature influence photosynthesis?

• Photosynthesis occurs faster at lower temperatures.

• Higher temperatures decrease the efficiency of photosynthesis.

• Temperature has no impact on photosynthesis.

• Temperature affects the rate of enzyme activity in photosynthesis.

Discuss the impact of light intensity on the process of photosynthesis.

• Photosynthesis occurs faster in the absence of light

• Higher light intensity decreases photosynthetic activity

• Light intensity impacts photosynthesis by influencing the rate at which it occurs. Higher light intensity generally leads to increased photosynthetic activity up to a certain threshold.

• Light intensity has no impact on photosynthesis