Post-Quiz (Chap5a Photosynthesis)

In an experiment, a plant’s thylakoid lumen is artificially acidified. What process would this directly stimulate?

• NADPH oxidation

• ATP synthase activity

• Carbon fixation

• Chlorophyll degradation

If a herbicide blocks plastoquinone in the ETC, which outcome is expected?

• Increased O2 release

• ATP production stops but NADPH continues

• Calvin Cycle speeds up

• PSI becomes overactive

Why might a desert plant have higher carotenoid levels compared to a shade plant?

• To absorb excess UV and dissipate heat.

• To reduce water loss.

• To enhance blue light absorption for PSII.

• To store extra energy as starch.

A bacterial species performs photosynthesis without releasing O2. What is its likely electron source?

• Water

• Hydrogen sulfide (H2S)

• NADPH

• Carbon dioxide

If the Calvin Cycle is inhibited, what immediate change occurs in the light reactions?

• ATP and NADPH accumulate.

• PSII absorbs more photons.

• Oxygen production increases.

• Chlorophyll switches to carotenoids.