Biology 122, Quiz 4, 2012
Name: ______________________________
Directions: 1) Print your name LEGIBLY on BOTH the scantron form and this question sheet; 2) Fill
in the scantron form appropriately – don’t mark on this question sheet; Turn both the scantron form
and this answer sheet in. There are 10 questions, each worth 1 point plus one extra credit question.
1. What products of light reactions of photosynthesis are used in the Calvin cycle?
A. oxygen and protons
B. carbon dioxide and water
C. ATP and NADPH
D. ADP and NADP
E. glucose and oxygen
2. The process in plants in which CO2 is released WITHOUT the production of ATP or
NADPH is called…
A. …carbon fixation.
B. ...oxygen fixation.
C. ...photophosphorylation.
D. ...photorespiration.
E. ...photooxidation.
3. A method devised by succulent desert plants to reduce the problem of photorespiration
is
A. the C3 pathway.
B. the CAM metabolism.
C. the Calvin cycle.
D. light reactions.
E. nitrogen fixation.
4. Carotenoids are important to many plants because these pigments are able to
A. remove carbon dioxide from the air.
B. absorb wavelengths of light that neither chlorophyll a nor b can absorb.
C. absorb water so that hydrolysis can be carried out in the chloroplasts.
D. capture UV radiation that is harmful to the DNA in the nucleus of plant cells.
E. store electrons for use during the "dark" reaction of photosynthesis.
5. Fall leaf color on deciduous trees is a result of
A. the production of more accessory pigments because of the cooler temperatures.
B. the reduction in the production of accessory pigments because of the cooler
temperatures.
C. cessation of chlorophyll production and its continued degradation, which allows
the accessory pigments to be revealed.
D. the increased angle of the sun during the fall, which reflects more of the accessory
pigments causing the human eye to see the red, yellow, and orange colors that were
masked by the green chlorophyll.
6. Which of the following is not part of the light-dependent reactions?
A. absorbing energy from photons
B. excitation of electrons in the reaction center of photosystems I and II
C. the fixation of carbon from CO2 in the Calvin Cycle
D. electron transport
E. chemiosmosis
7. Which of following statements about G proteins associated with G-protein-coupled
receptors is false?
A. G proteins provide a link between the receptor and effector protein.
B. G proteins can propagate the signal by either the G or the G components.
C. G proteins are heterotrimeric.
D. Associated G proteins become active by exchanging GTP for GDP.
E. Activated G protein diffuses away from the receptor.
8. A small number of surface receptors can ultimately generate a large intracellular
response, as each step of the pathway is often expanded by
A. enzymatic receptors.
B. gated ion channels.
C. enzyme mediated signal amplification.
D. G-protein-coupled receptors.
9. A biochemist is designing a new drug that will mimic the shape and function of a
particular intercellular signaling molecule. Therefore she must produce a molecule that
will bind to the receptor protein and
A. induce a change in the receptor molecule shape, which will ultimately prevent a
cellular response.
B. induce a change in the receptor molecule shape, which will ultimately produce a
cellular response.
C. induce a change in the phospholipid bilayer that causes a polar reversal allowing the
molecules to be endocytosed.
D. produce a cellular response by altering the Na+/K+ pump located near the receptor site.
10. Potassium (K) channels can open in response to signals. Even though Na+ is a smaller
ion than K+, a K channel is permeable to K+ but not Na+ in its open state. This selectivity
is due to…
A. electrostatic attraction between water and the K+ ions
B. electrostatic attraction between certain main chain oxygens of the channel and
the K+ ions
C. the opening of the channel being negatively charged, attracting K+ but not Na+
11. You are planning to perform some protein-protein interaction studies to identify a
receptor for a steroid hormone you have been working on. Which of the following cell
extracts would be expected to contain the steroid hormone receptor?
A. plasma membrane
B. extracellular
C. cytoplasmic
D. nuclear