Photosynthesis Applications and Implications 3

Question 1

Vertical farming uses LED lights tuned to specific wavelengths to maximize crop growth. Which combination is most effective for photosynthesis?

Accepted Answer

Blue and red

Answer

Blue light (~450 nm) and red light (~680 nm) match chlorophyll absorption peaks, making them the most energy-efficient choices.

Question 2

Global ocean warming threatens marine ecosystems partly because warmer water holds less dissolved CO2. What photosynthesis-related consequence does this have for phytoplankton?

Accepted Answer

Reduced carbon fixation rates and decreased primary productivity

Answer

Less dissolved CO2 limits the substrate available for carbon fixation, reducing phytoplankton primary productivity.

Question 3

Which statement best explains why C4 crops like sugarcane are preferred for bioethanol production in tropical regions?

Accepted Answer

Their C4 pathway minimizes photorespiration, yielding more biomass per unit of water

Answer

C4 plants concentrate CO2 around RuBisCO, suppressing wasteful photorespiration and improving biomass yield under hot, sunny conditions.

Question 4

Scientists are engineering crops with modified RuBisCO enzymes. What is the primary goal of this modification?

Accepted Answer

To increase CO2 specificity and reduce oxygenase activity that causes photorespiration

Answer

RuBisCO can mistakenly bind O2 instead of CO2; engineering higher CO2 specificity would reduce photorespiration and increase yield.

Question 5

A solar panel farm and a cropland of equal area are compared for energy capture efficiency. Why do most crop plants convert less than 1% of incoming solar energy into stored biomass?

Accepted Answer

Most wavelengths are not absorbed by chlorophyll, and metabolic costs further reduce net energy storage

Answer

Chlorophyll absorbs only a fraction of the solar spectrum, and respiration, photorespiration, and other metabolic losses further reduce net yield.

Photosynthesis Practice Test

Photosynthesis Practice Test

Photosynthesis Applications and Implications 3