Photosynthesis in Higher Plants quiz

Who showed that the oxygen released in photosynthesis comes from water?

The reaction centre of photosystem II is:

The first stable product of the Calvin cycle is:

The primary CO2 acceptor in C4 plants is:

Splitting of water occurs in association with:

The enzyme RuBisCO acts as an oxygenase during:

Cyclic photophosphorylation produces:

Which pigment is called the chief pigment of photosynthesis?

The dark reaction occurs in the:

Who first demonstrated that plants restore the air spoiled by a burning candle?

What did Ingenhousz show in his experiment with an aquatic plant? (2 marks)

What did Sachs's experiment prove? (2 marks)

Why are accessory pigments important? (2 marks)

Distinguish between cyclic and non-cyclic photophosphorylation. (2 marks)

What are the three stages of the Calvin cycle? (2 marks)

Why do C4 plants show no photorespiration? (2 marks)

What is the role of ATP synthase in chloroplasts? (2 marks)

What is the role of NADPH in the Calvin cycle? (2 marks)

Why does the rate of photosynthesis fall at high temperatures? (2 marks)

How does water stress reduce photosynthesis? (2 marks)

In the Calvin cycle, 6 molecules of CO2 combine with 6 RuBP. Calculate the number of PGA molecules formed. (3 marks)

If a plant fixes 132 g of CO2, calculate the mass of glucose formed (C = 12, H = 1, O = 16). (3 marks)

A leaf releases 32 mg of oxygen per hour. Calculate the moles of O2 released per hour and the moles of glucose formed. (3 marks)

In an experiment, the rate of photosynthesis doubles when temperature rises from 15 to 25 degrees C. If the rate at 15 degrees C is 6 units, calculate the rate at 25 degrees C and the temperature coefficient. (3 marks)

Light saturation occurs at about 10% of full sunlight. If full sunlight is 2,000 units, calculate the intensity at light saturation. (3 marks)

Read the passage and answer the questions. Joseph Priestley in 1770 performed a series of experiments that revealed the essential role of air in the growth of green plants. He observed that a candle burning in a closed space, a bell jar, soon gets extinguished. Similarly, a mouse would soon suffocate in a closed space. He then placed a mint plant in the same bell jar and found that the mouse stayed alive and the candle continued to burn. (i) What did Priestley conclude? (ii) What gas did he later discover? (iii) What did Ingenhousz add to this finding? (5 marks)

Read the passage and answer the questions. The light reactions include light absorption, water splitting, oxygen release and the formation of high-energy chemical intermediates, ATP and NADPH. The pigments are organised into two discrete photochemical light harvesting complexes within photosystem I and photosystem II. (i) Where do the light reactions occur? (ii) What are the products of the light reaction? (iii) What is the role of the reaction centre? (5 marks)

Read the passage and answer the questions. Plants that are adapted to dry tropical regions have the C4 pathway. Though these plants have oxaloacetic acid as the first CO2 fixation product, they use the C3 pathway or the Calvin cycle as the main biosynthetic pathway. The leaves of C4 plants have large cells around the vascular bundles called bundle sheath cells. (i) What is the first CO2 acceptor in C4 plants? (ii) Why do bundle sheath cells have no intercellular spaces? (iii) Name two C4 plants. (5 marks)

Read the passage and answer the questions. RuBisCO is the most abundant enzyme in the world. It has a much greater affinity for CO2 than for O2. Under high O2 concentration, it binds with O2 instead of CO2, forming one molecule of phosphoglycerate and one molecule of phosphoglycolate in a pathway called photorespiration. (i) Why is photorespiration wasteful? (ii) When does photorespiration increase? (iii) How do C4 plants avoid it? (5 marks)

Read the passage and answer the questions. A farmer grows tomatoes in a greenhouse. He supplies extra carbon dioxide to the greenhouse and maintains the temperature and light. He finds that the yield increases. (i) Why does extra carbon dioxide increase yield? (ii) What is the limiting factor in this case? (iii) What would happen if the light intensity were reduced? (5 marks)

Describe the early experiments on photosynthesis and the contribution of each scientist. (6 marks)

Explain the structure of the chloroplast and the pigments involved in photosynthesis. What do the absorption and action spectra show? (6 marks)

Describe the light reactions of photosynthesis with the Z scheme. Explain cyclic and non-cyclic photophosphorylation. (6 marks)

Describe the Calvin cycle with a labelled diagram. Calculate the ATP and NADPH requirements for glucose synthesis. (6 marks)

Describe the C4 pathway and photorespiration. Explain the factors affecting photosynthesis. (6 marks)