Chapter 6

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

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

In plants, photosynthetic eukaryotes, and cyanobacteria, the light-dependent reactions proceed in/at the ___. a. thylakoid membrane b. plasma membrane c. stroma d. cytoplasm

Most of the carbon that land plants use for photosynthesis comes from ___. a. sugars c. water b. the atmosphere d. soil

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

When a photosystem absorbs light energy, ____. a. sugar phosphates are produced b. electrons are transferred to ATP c. electrons are ejected from its special pair

In the light-dependent reactions, a. carbon dioxide is fixed b. ATP forms c. \(\mathrm{CO}_{2}\) accepts electrons d. sugars form

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

The atoms in the oxygen molecules released during photosynthesis come from a. sugars b. \(\mathrm{CO}_{2}\) c. water \(\mathrm{d} . \mathrm{O}_{2}\)

In chloroplasts, the light-independent reactions proceed at/in the ___ a. thylakoid membrane b. plasma membrane c. stroma d. cytoplasm

The Calvin-Benson cycle starts with ___ a. the absorption of photon energy b. carbon fixation c. the release of electrons from photosystem II d. NADP+ formation

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

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

In \(C 3\) plants, ___ makes sugar production inefficient when stomata close on hot, dry days. a. photosynthesis b. photolysis c. photorespiration d. carbon fixation

Match each term with its most suitable description. $$ \text { PGAL formation } \quad \quad\quad\quad\quad \text { a. absorbs light } $$ $$ \text { \(\mathrm{CO}_{2}\) fixation } \quad \quad\quad\quad\quad \text { b. converts light to chemical energy } $$ $$ \text { autotroph } \quad \quad\quad\quad\quad \text { c. self-feeder } $$ $$ \text { ATP forms; NADPH does not } \quad \quad\quad\quad\quad \text { d. electrons cycle back to photosystem } $$ $$ \text { photorespiration } \quad \quad\quad\quad\quad \text { e. problem in \(C 3\) plants } $$ $$ \text { photosynthesis } \quad \quad\quad\quad\quad \text { f. Calvin- Benson cycle product } $$ $$ \text { pigment } \quad \quad\quad\quad\quad \text { g. water molecules split } $$ $$ \text { photolysis in photosynthesis } \quad \quad\quad\quad\quad \text { h. rubisco function } $$