Plant Growth and Photosynthesis Quiz

A farmer noticed that his plants' growth had slowed despite regular watering. He shaded half of his field to protect the plants from direct sunlight. After a few weeks, he observed that the shaded plants showed poorer growth than those in direct sunlight. What could be the primary reason?

• The shaded plants could not perform the light-dependent reactions efficiently.

• The plants in direct sunlight received more nutrients from the soil.

• The shaded plants lost the ability to absorb water efficiently.

• The plants in the sun were able to respire more effectively.

A scientist is conducting an experiment on two identical plants: one is placed in a room with blue and red light, and the other in a room with only green light. After two weeks, the plant in the green light room shows signs of wilting. Why did this happen?

• The green light is absorbed more efficiently, causing excessive energy intake.

• Green light is reflected rather than absorbed, reducing the efficiency of photosynthesis.

• Green light triggers an increased rate of transpiration, leading to dehydration.

• The plant in the blue and red light room used water more efficiently.

A gardener places two identical plants in separate containers-one in direct sunlight and the other in a dimly lit room. After a week, the plant in the dim room has yellowing leaves. What is the best explanation for this?

• The plant in the dim room received too much oxygen.

• The plant in direct sunlight absorbed too much water.

• The plant in the dim room could not perform sufficient photosynthesis to sustain chlorophyll production.

• The plant in the dim room used up its starch reserves.

A researcher investigates the effect of different carbon dioxide (CO₂) concentrations on plant growth. He places three plants in separate sealed containers with varying CO₂ levels (low, normal, high). After a week, the plant with high CO₂ shows better growth than the other two. Why?

• High CO₂ levels increase the rate of light-dependent reactions.

• Carbon dioxide is directly used in the light-independent reactions to produce glucose.

• High CO₂ concentration prevents water loss, aiding photosynthesis.

• More CO₂ increases the plant's oxygen consumption.

In an experiment, a student removed a leaf from a plant kept in the dark for 48 hours and tested it for starch. The test was negative. What is the most logical conclusion?

• The plant does not require starch for energy.

• The plant lost its ability to produce glucose.

• The absence of light prevented the light-dependent reaction, which halted glucose production.

• The leaf had too much oxygen, preventing starch formation.

A farmer used artificial grow lights in his greenhouse, but his plants were still growing slowly. After investigation, he realized that the lights only emitted green wavelengths. What should he do?

• Use red and blue light, which are more effective for photosynthesis.

• Increase the duration of green light exposure.

• Add more green-colored plants to absorb the light.

• Spray nutrients on the leaves to compensate for light deficiency.

In a desert, cacti perform photosynthesis differently from most plants. They open their stomata at night to take in CO₂. What advantage does this provide?

• It prevents excessive water loss during the day.

• It increases the rate of glucose production.

• It allows the light-dependent reaction to occur at night.

• It decreases oxygen release, conserving energy.

A scientist discovers a new plant species that thrives in deep-sea environments with very little sunlight. What might be its primary source of energy for survival?

• It likely uses alternative pigments for photosynthesis.

• It depends solely on respiration.

• It does not require glucose for survival.

• It produces energy using minerals from the ocean.

A gardener wants to maximize plant growth by exposing them to 24 hours of continuous light. What will most likely happen?

• The plants will thrive due to constant photosynthesis.

• The plants will overheat and stop photosynthesizing.

• The plants will experience stress, affecting the light-independent reaction.

• The plant roots will compensate by absorbing more water.

During an experiment, a student finds that a plant continues producing oxygen even after being placed in a sealed jar. What does this suggest?

• The plant is performing respiration instead of photosynthesis.

• The jar contains enough CO₂ for photosynthesis to continue.

• Oxygen is not a byproduct of photosynthesis.

• Photosynthesis is independent of external conditions.