Pre-Quiz (Chap5a Photosynthesis)

In a dense forest, certain plants grow under the canopy where sunlight is limited. Which pigment would most help these plants maximize light absorption for photosynthesis?

• Chlorophyll a

• Chlorophyll b

• Carotenoids

• Phycobilins

A scientist observes that disrupting the electron transport chain (ETC) in thylakoids stops ATP production but not NADPH synthesis. Which component of photosynthesis is most likely affected?

• Photosystem I

• Photosystem II

• Calvin Cycle enzymes

• Stroma pH

If a mutation prevents water splitting in photosynthesis, what immediate effect would this have on the light reactions?

• Increased NADPH production

• No oxygen release and halted electron flow

• Enhanced ATP synthesis

• Faster Calvin Cycle

Why might algae in deep water use phycobilins instead of carotenoids as accessory pigments?

• Phycobilins absorb green/yellow light penetrating deep water.

• Carotenoids are toxic underwater.

• Phycobilins block UV radiation.

• Chlorophyll a cannot function with carotenoids.

A plant is exposed to light wavelengths of 700 nm. Which photosystem would be most active, and what would it produce?

• PSII → ATP

• PSI → NADPH

• Both PSI and PSII → Glucose

• Neither → No reaction