AP Biology Unit 3 Chapter 8

In photosynthesis, plants use carbon from __________ to make sugar and other organic molecules. (Section 8.1)

• the sun

• water

• carbon dioxide

• chlorophyll

• soil

How does carbon dioxide enter the leaf? (Section 8.1)

• through the stomata

• through the roots

• through the vascular system

• through the chloroplasts

• through the chloroplasts

In a rosebush, speaking as specifically as possible, chlorophyll is located in __________. (Section 8.1)

• thylakoids, which are in mesophyll cells in the chloroplasts of a leaf

• thylakoids, which are in chloroplasts in the mesophyll cells of a leaf

• mesophyll cells, found within the thylakoids of a leaf's chloroplasts

• chloroplasts, which are in mesophyll cells in the thylakoids of a leaf

• chloroplasts, which are in thylakoids in the mesophyll cells of a leaf

Chlorophyll molecules are in which part of the chloroplast? (Section 8.1)

• stroma

• plasma membrane

• stomata

• thylakoid membranes

• thylakoid lumen

The source of the oxygen produced by photosynthesis has been identified through experiments using radioactive tracers. The oxygen comes from __________. (Section 8.1)

• radioisotopes

• carbon dioxide

• water

• glucose

• light

In photosynthesis, what is the fate of the oxygen atoms present in CO₂? They end up __________. (Section 8.1)

• as molecular oxygen

• as molecular oxygen and in sugar molecules

• in sugar molecules and in water

• in water

• in sugar molecules

The reactions of the Calvin cycle are not directly dependent on light, but they usually do not occur at night. Why? (Section 8.1)

• The Calvin cycle requires products only produced when the photosystems are illuminated.

• Carbon dioxide concentrations decrease at night.

• It is often too cold at night for these reactions to take place.

• At night, no water is available for the Calvin cycle.

• Plants usually open their stomata at night.

The Calvin cycle occurs in the __________. (Section 8.1)

• thylakoid membrane

• matrix

• stomata

• thylakoid lumen

• stroma

A photon of which color would carry the most energy? (Section 8.2)

• red

• orange

• yellow

• green

• blue

The most important role of pigments in photosynthesis is to __________. (Section 8.2)

• catalyze the synthesis of ATP

• screen out harmful ultraviolet rays

• store energy

• capture light energy

• catalyze the hydrolysis of water