Question 1: Define a limiting factor in the context of photosynthesis.

Answer: A limiting factor is a variable that restricts or slows down the rate of photosynthesis when its level is not optimal.

Question 2: List three environmental factors that can act as limiting factors during photosynthesis.

Answer: Light intensity, carbon dioxide concentration, and temperature.

Question 3: Explain why light intensity can be a limiting factor for photosynthesis.

Answer: Light intensity affects the energy available for the light-dependent reactions of photosynthesis. If light is too weak, the rate of these reactions decreases, limiting the overall rate of photosynthesis.

Question 1: If a plant's rate of photosynthesis is measured at 8 units when carbon dioxide concentration is 0.04 mol/L, and at 12 units when concentration increases to 0.08 mol/L, calculate the rate of photosynthesis at 0.06 mol/L assuming a linear relationship.

Answer: 10 units

Question 2: A plant shows a maximum photosynthesis rate of 20 units at 25°C. If the rate drops to 12 units at 35°C, what is the percentage decrease in the rate?

Answer: 40%

Question 1: Describe a simple experiment to test how light intensity affects the rate of photosynthesis in aquatic plants. Include the variables you would control and measure.

Answer: Use a pondweed in water under different light intensities, keeping temperature, carbon dioxide levels, and water volume constant. Measure the amount of oxygen produced over time at each light level to determine the effect of light intensity.

Question 2: Identify the independent variable, dependent variable, and at least two controlled variables in the experiment described above.

Answer: Independent variable: Light intensity; Dependent variable: Rate of photosynthesis (oxygen produced); Controlled variables: Temperature, carbon dioxide concentration, water volume.

Question 1: A plant's photosynthesis rate is observed to increase with rising temperature up to 30°C, after which it declines. Explain why temperature has this effect and identify the optimal temperature range for most plants.

Answer: Temperature influences enzyme activity involved in photosynthesis. As temperature rises, enzyme activity increases, boosting the rate. Beyond the optimal temperature (around 30°C), enzymes may denature, causing the rate to decline. Most plants have an optimal temperature range of 20-30°C.

Question 1: Explain how greenhouse farmers can optimize conditions to maximize photosynthesis and crop yield.

Answer: Greenhouse farmers can control light, temperature, and carbon dioxide levels to ensure they are at optimal conditions for photosynthesis. Using supplemental lighting, heating systems, and CO2 enrichment can enhance plant growth and increase crop yields.

Question 2: Which limiting factor is most likely to restrict photosynthesis in a city park during a cloudy day? A) Light intensity B) Carbon dioxide concentration C) Temperature D) Water availability

Answer: