The process of photosynthesis probably originated ________.

• in plants

• in prokaryotes

• in fungi

• three separate times during evolution

If photosynthesizing green algae are provided with CO2 containing heavy oxygen (18O), later analysis will show that all of the following molecules produced by the algae contain 18O EXCEPT

• 3-phosphoglycerate

• glyceradehyde 3-phosphate (G3P)

• glucose

• ribulose bisphosphate (RuBP)

• O2

Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?

• CO2 and glucose

• H2O and O2

• ADP, Pi, and NADP+

• Electrons and H+

• ATP and NADPH

When oxygen is released as a result of photosynthesis, it is a direct by-product of ________.

• reducing NADP+

• splitting water molecules

• chemiosmosis

• the electron transfer system of photosystem I

• the electron transfer system of photosystem II

Which of the following statements best describes the relationship between photosynthesis and respiration?

• Respiration runs the biochemical pathways of photosynthesis in reverse.

• Photosynthesis stores energy in complex organic molecules; respiration releases energy from complex organic molecules.

• Photosynthesis occurs only in plants; respiration occurs only in animals.

• ATP molecules are produced in photosynthesis but not in aerobic respiration.

• Photosynthesis is catabolic; respiration is anabolic.

In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during ________.

• photosynthesis only

• respiration only

• photosynthesis and respiration

• neither photosynthesis nor respiration

• photorespiration only

Which of the following sequences correctly represents the flow of electrons during photosynthesis?

• NADPH → O2 → CO2

• H2O → NADPH → Calvin cycle

• NADPH → chlorophyll → Calvin cycle

• H2O → photosystem I → photosystem II

• NADPH → electron transport chain → O2

Plants photosynthesize _______.

• only in the light but respire only in the dark

• only in the dark but respire only in the light

• only in the light but respire in light and dark

• and respire only in the light

• and respire only in the dark

Chlorophylls absorb most light in which colors of the visible range?

• Green and blue

• Blue and red

• Green and red

• Violet and red

Which of the following is a difference between chlorophyll a and chlorophyll b?

• Chlorophyll a is a pigment, and chlorophyll b is the enzyme that transfers excited electrons from chlorophyll a to electron carriers of the thylakoid membrane.

• Chlorophyll a absorbs yellow light, and chlorophyll b absorbs green.

• Chlorophyll a contains magnesium in its ring structure, whereas chlorophyll b contains iron.

• Chlorophyll a and b absorb light energy at slightly different wavelengths.