Free BioInteractive Measuring Photosynthesis Questions and Answers — Questions and Answers
Question 1: Which gas is primarily measured to determine the rate of photosynthesis?
- Oxygen (O₂)
- Carbon dioxide (CO₂) (Correct answer)
- Nitrogen (N₂)
- Methane (CH₄)
Correct answer: Carbon dioxide (CO₂)
Carbon dioxide (CO₂) is a key reactant in photosynthesis, being absorbed from the atmosphere and fixed into organic compounds during the Calvin Cycle. Therefore, measuring the rate of CO₂ uptake by a plant is a direct and common method used to determine its photosynthetic activity and efficiency.
Question 2: What device is commonly used to measure CO₂ uptake during photosynthesis?
- Spectrophotometer
- Fluorometer
- Infrared Gas Analyzer (IRGA) (Correct answer)
- pH meter
Correct answer: Infrared Gas Analyzer (IRGA)
An Infrared Gas Analyzer (IRGA) is a specialized scientific instrument commonly used to measure the concentration of gases like CO₂ and water vapor. In photosynthesis research, IRGAs are crucial for precisely quantifying the rate of CO₂ uptake or release by plants, thereby determining photosynthetic or respiratory rates.
Question 3: What is chlorophyll fluorescence used to assess in photosynthesis?
- Oxygen production
- Light absorption efficiency
- Photosystem II activity (Correct answer)
- Glucose concentration
Correct answer: Photosystem II activity
Chlorophyll fluorescence is a non-invasive technique used to assess the efficiency and activity of Photosystem II (PSII) in photosynthesis. By measuring the re-emitted light from chlorophyll, scientists can gain insights into how effectively light energy is being captured and utilized in the initial stages of photosynthesis, indicating plant stress or health.
Question 4: In an aquatic plant experiment, what does observing oxygen bubbles indicate?
- Respiration rate
- Rate of photosynthesis (Correct answer)
- Chlorophyll breakdown
- Nutrient uptake
Correct answer: Rate of photosynthesis
Oxygen gas is a significant byproduct of the light-dependent reactions of photosynthesis, released when water molecules are split. Therefore, observing and quantifying the production of oxygen bubbles from an aquatic plant under illuminated conditions directly indicates the rate at which photosynthesis is occurring.
Question 5: Which parameter represents the total CO₂ fixed during photosynthesis without accounting for respiration?
- Net photosynthetic rate
- Gross photosynthetic rate (Correct answer)
- Quantum yield
- Light compensation point
Correct answer: Gross photosynthetic rate
Gross photosynthetic rate represents the total amount of carbon dioxide fixed by photosynthesis, without subtracting the CO₂ released through cellular respiration. It reflects the plant's maximum potential for carbon assimilation before accounting for its own metabolic energy needs.
Free BioInteractive Measuring Photosynthesis Questions and Answers
Which gas is primarily measured to determine the rate of photosynthesis?