Chapter 6

A cat eats a bird, which ate a caterpillar that chewed on a weed. Which organisms are autotrophs? Which ones are heterotrophs?

Plants use ______________ as an energy source to drive photosynthesis. a. sunlight c. \(\mathrm{O}_{2}\) b. hydrogen ions \(\mathrm{d} . \mathrm{CO}_{2}\)

Most of the carbon dioxide that plants use for photosynthesis comes from _____________. a. glucose c. rainwater b. the atmosphere d. photolysis

Which of the following statements is incorrect? a. Pigments absorb light of certain wavelengths only. b. Many accessory pigments are multipurpose molecules. c. Chlorophyll is green because it absorbs green light.

5\. In plants and other photosynthetic eukaryotes, the lightdependent reactions proceed in/at the ____________. a. thylakoid membrane c. stroma b. plasma membrane d. cytoplasm

When a photosystem absorbs light, ___________. a. sugar phosphates are produced b. electrons are transferred to ATP c. \(\mathrm{RuBP}\) accepts electrons d. electrons are ejected from its special pair

What accumulates inside the thylakoid compartment of chloroplasts during the light-dependent reactions? a. sugars c. \(\mathrm{O}_{2}\) b. hydrogen ions d. \(\mathrm{CO}_{2}\)

Light-independent reactions in plants proceed in/at the ____________ of chloroplasts. a. thylakoid membrane c. stroma b. plasma membrane d. cytoplasm

The Calvin-Benson cycle starts when ____________. a. light is available b. carbon dioxide is attached to RuBP c. electrons leave a photosystem II

Which of the following substances does not participate in the Calvin-Benson cycle? a. ATP d. PGAL b. NADPH e. \(\mathrm{O}_{2}\) c. RuBP f. \(\mathrm{CO}_{2}\)

Closed stomata ____________. a. limit gas exchange c. restrict photosynthesis b. permit water loss d. absorb light

In \(\mathrm{C} 3\) plants,_____________ makes sugar production inefficient when stomata close during the day. a. photosynthesis c. photorespiration b. photolysis d. carbon fixation

Match each with its most suitable description. PGAL formation ______\(\mathrm{CO}_{2}\) fixation ______photolysis ______ATP forms; NADPH does not ______photorespiration ______photosynthesis ______pigment ______autotroph a. absorbs light b. converts light to chemical energy c. self-feeder d. electrons cycle back to photosystem I e. problem in \(\mathrm{C} 3\) plants f. ATP, NADPH required g. water molecules split h. rubisco function