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Biology

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21. The main photosynthetic pigments in plants are _______ and _______.
a. chlorophyll s; chlorophyll a
b. chlorophyll x; chlorophyll y
c. retinal pigment; accessory pigment
d. chlorophyll a; chlorophyll b
e. None of the above

22. Why is the absorption spectrum of chlorophyll a not identical to the action spectrum of photosynthesis?
a. Accessory pigments contribute energy to drive photosynthesis.
b. Chlorophyll a absorbs both red and blue light.
c. Chlorophyll a reflects green light.
d. Different wavelengths of light have different energies.
e. Chlorophyll a can be activated by absorbing a photon of light.

23. The photosynthetic pigment chlorophyll a absorbs
a. infrared light.
b. orange-red and blue light.
c. X rays.
d. gamma rays.
e. white light.

24. Accessory pigments
a. play no role in photosynthesis.
b. transfer energy from chlorophyll to the electron transport chain.
c. absorb only the red wavelengths.
d. allow plants to absorb visible light of intermediate wavelengths.
e. transfer electrons to NADP.

25. What is the difference between chlorophyll a and chlorophyll b?
a. Chlorophyll a has a complex ring structure, whereas chlorophyll b has a linear structure.
b. Chlorophyll a has a magnesium atom at its center, whereas chlorophyll b has a phosphate group at its center.
c. Chlorophyll a has a methyl group, whereas chlorophyll b has an aldehyde group.
d. A hydrocarbon tail is found only in chlorophyll a.
e. Chlorophyll a fluoresces, whereas chlorophyll b passes the absorbed energy to another molecule.

26. When a photon is absorbed by chlorophyll,
a. the chlorophyll becomes "excited," or energized.
b. a greater number of light wavelengths can be absorbed.
c. ATP is split into ADP, phosphate, and energy.
d. hydrogen ions are released.
e. the chlorophyll molecules fluoresce.

27. The precise moment when light energy is captured in chemical energy is the point at which
a. light shines on chlorophyll.
b. water is hydrolyzed.
c. chlorophyll is oxidized.
d. chlorophyll is reduced.
e. the CO2 from air is captured in a sugar.

28. In noncyclic photophosphorylation, water is used for the
a. hydrolysis of ATP.
b. excitation of chlorophyll.
c. reduction of chlorophyll.
d. oxidation of NADPH.
e. synthesis of chlorophyll.

29. In noncyclic photophosphorylation, electrons from _______ replenish chlorophyll molecules that have given up electrons.
a. CO2
b. water
c. NADPH + H+
d. O2 gas
e. None of the above

30. The O2 gas produced during photosynthesis is derived from
a. CO2.
b. glucose.
c. water.
d. CO.
e. bicarbonate ions.