BIO 308 EXAM 3 QUESTIONS COMPLETE
WITH VERIFIED ANSWERS
\.Consider the redox pair CO2/CH4. Which description below is true of the pair?
A) CO2 is oxidized by CH4
B) CO2 is reduced by CH4
C) CO2 is a resulting product when CH4 is oxidized by another molecule
D) CO2 is a resulting product when CH4 is reduced by another molecule -
ANSWERS✔-C) CO2 is a resulting product when CH4 is oxidized by another
molecule
\.For the carbon cycle, decide which bacteria could carry conversion A using the
list below.
an aerobic heterotroph, like Pseudomonas
A)a fermentative heterotroph, like Clostridium
B)a methanogen, like Methanobacterium
C)a methane-oxidizing bacterium
D)An NH4+ oxidizing bacterium - ANSWERS✔-D)An NH4+ oxidizing bacterium
\.Nitrification involves:
A) The reduction of ammonium to nitrites
,B) The oxidation of ammonium to nitrites
C) The fixation of nitrogen gas to ammonium
D) The reduction of nitrates to nitrogen gas
E) The oxidation of nitrates into nitrogen gas - ANSWERS✔-B) The oxidation of
ammonium to nitrites
\.What is the most stable form of nitrogen?
A)NO
B)NO2-
C)N2
D)NH3
E)NH - ANSWERS✔-C)N2
\.What is the cause of the highlighted zone (dead zone in Gulf of Mexico) with
dissolved oxygen less than 2.0 mg/l?
A) High iron concentrations
B) Deep water horizon oil spill
C) High carbon and nitrogen concentrations
D) Low oxygen concentrations
E) High phosphorus concentrations - ANSWERS✔-C) High carbon and nitrogen
concentrations
\.The reactions on the right side of the table occur only:
A) under thermophilic conditions.
, B) under anaerobic conditions.
C) deep within Earth's crust.
D) Under aerobic conditions
(REVIEW SLIDE #13) - ANSWERS✔-B) under anaerobic conditions.
\.The term ____ refers to heat energy absorbed or released, whereas ____ is a
measure of disorder or randomness.
A) enthalpy, free energy
B) enthalpy, entropy
C) entropy, enthalpy
D) free energy, entropy
E) free energy, enthalpy - ANSWERS✔-B) enthalpy, entropy
\.Which of the following statements is NOT true regarding the electron donors in
prokaryotic metabolism?
A) The use of organic compounds as electron donors is known as organotrophy
B) Chemolithiotrophy refers to the use of inorganic molecules and electron
sources
C) Oxygen can serve as an electron donor
D) Electrons can be obtained from inorganic chemicals such as H2S - ANSWERS✔-
C) Oxygen can serve as an electron donor
\.An ATP molecule carries energy in the cell but needs to be stabilized. When is it
stabilized?
WITH VERIFIED ANSWERS
\.Consider the redox pair CO2/CH4. Which description below is true of the pair?
A) CO2 is oxidized by CH4
B) CO2 is reduced by CH4
C) CO2 is a resulting product when CH4 is oxidized by another molecule
D) CO2 is a resulting product when CH4 is reduced by another molecule -
ANSWERS✔-C) CO2 is a resulting product when CH4 is oxidized by another
molecule
\.For the carbon cycle, decide which bacteria could carry conversion A using the
list below.
an aerobic heterotroph, like Pseudomonas
A)a fermentative heterotroph, like Clostridium
B)a methanogen, like Methanobacterium
C)a methane-oxidizing bacterium
D)An NH4+ oxidizing bacterium - ANSWERS✔-D)An NH4+ oxidizing bacterium
\.Nitrification involves:
A) The reduction of ammonium to nitrites
,B) The oxidation of ammonium to nitrites
C) The fixation of nitrogen gas to ammonium
D) The reduction of nitrates to nitrogen gas
E) The oxidation of nitrates into nitrogen gas - ANSWERS✔-B) The oxidation of
ammonium to nitrites
\.What is the most stable form of nitrogen?
A)NO
B)NO2-
C)N2
D)NH3
E)NH - ANSWERS✔-C)N2
\.What is the cause of the highlighted zone (dead zone in Gulf of Mexico) with
dissolved oxygen less than 2.0 mg/l?
A) High iron concentrations
B) Deep water horizon oil spill
C) High carbon and nitrogen concentrations
D) Low oxygen concentrations
E) High phosphorus concentrations - ANSWERS✔-C) High carbon and nitrogen
concentrations
\.The reactions on the right side of the table occur only:
A) under thermophilic conditions.
, B) under anaerobic conditions.
C) deep within Earth's crust.
D) Under aerobic conditions
(REVIEW SLIDE #13) - ANSWERS✔-B) under anaerobic conditions.
\.The term ____ refers to heat energy absorbed or released, whereas ____ is a
measure of disorder or randomness.
A) enthalpy, free energy
B) enthalpy, entropy
C) entropy, enthalpy
D) free energy, entropy
E) free energy, enthalpy - ANSWERS✔-B) enthalpy, entropy
\.Which of the following statements is NOT true regarding the electron donors in
prokaryotic metabolism?
A) The use of organic compounds as electron donors is known as organotrophy
B) Chemolithiotrophy refers to the use of inorganic molecules and electron
sources
C) Oxygen can serve as an electron donor
D) Electrons can be obtained from inorganic chemicals such as H2S - ANSWERS✔-
C) Oxygen can serve as an electron donor
\.An ATP molecule carries energy in the cell but needs to be stabilized. When is it
stabilized?
