BI 234 Exam BEST STUDYING
MATERIAL WITH VERIFIED ANSWERS
LATEST UPDATE NEW VERSION 2024-
2025 GRADED A.
You observe a cell through a microscope and see that it has mitochondria. To which
Domain of
organisms does it belong?
a. Bacteria b. Archaea c. Animalia (Animals) d. Eukarya
e. Cannot be determined from the information provided
- ANSWER D. Eukarya consist of animals, plants, fungi and protists
Which of the following is NOT true of ionic bonds?
a. They are formed due to the mutual attraction of cations and anions
b. Electrons are shared by atoms
c. They are weaker than covalent bonds
d. They are stronger than hydrogen bonds
e. None of the above (all of the above are true of ionic bonds)
- ANSWER B. Ionic bonds are formed when atoms gain or lose electrons in the outer
energy level
Which of the following statements is NOT true of biological organic molecules?
a. They're usually polymers formed from subunits (monomers)
b. Monomers are linked (bonded) together by hydrolysis ("water splitting")
c. Always contain hydrogen and carbon
d. Their atoms are mostly or entirely covalently bonded
e. None of the above (i.e., all of the above are true)
- ANSWER B. Hyrdrolysis is a decomposing reaction
Which of the following statements is NOT true?
a. Decomposition (degradation, catabolic) reactions are usually endergonic
b. Enzymes increase the probability that a chemical reaction will take place by lowering
the activation energy
c. Chemical reactions in living cells are catalyzed by enzymes
d. The energy required to cause a chemical reaction to occur is called the activation
energy
e. None of the above (all of these statements are true)
- ANSWER A. Decomposition reactions are usually exergonic, releasing energy
If a bacterial cell is placed in a hypertonic (hyperosmotic) solution:
a. Water moves through the plasma membrane into the cell
b. The cell undergoes osmotic lysis
,c. Water moves through the plasma membrane out of the cell, causing plasmolysis
d. There is no net movement of water either into or out of the cell
e. None of the above describes what happens in a hypertonic solution
- ANSWER C.
All of the following are correctly matched and can be found in bacteria EXCEPT:
a. Ribosomes - site of protein synthesis
b. Cell (plasma) membrane - encloses cytoplasm; phospholipid bilayer with proteins
c. Cell wall - contains peptidoglycan
d. Nucleus - membrane-bound organelle containing multiple chromosomes
e. None of the above (all are correctly matched and can be found in bacteria) -
ANSWER D. Bacteria are prokaryotes which do not have a nucleus
In the Gram stain, gram-positive bacteria are dark purple for all the following reasons
EXCEPT:
a. The counterstain (safranin) causes the purple color to develop
b. Thick peptidoglycan in the gram-positive cell wall prevents decolorization by alcohol
c. Crystal Violet is fixed inside the cell as a CV-iodine complex once iodine is added
d. The primary stain, Crystal Violet, is dark purple
e. None of the above (All are reasons that gram-positive bacteria are purple in the Gram
stain)
- ANSWER A. Safranin is a counterstain that is used to color the gram-negative bacteria
that lose their color after decolorization
Which of the following is NOT true about chemoheterotrophs?
a. Use organic compounds as a source of both carbon and energy
b. Can use light for energy and CO2 as a source of carbon
c. They are ultimately dependent on autotrophs to provide their carbon and energy
d. Oxidize organic compounds (e.g., glucose) to generate ATP
e. None of the above (All are true of chemoheterotrophs)
- ANSWER B Chemoheterotrophs are unable to utilize carbon dioxide to form their own
organic compounds
Which of the following is NOT true of photosynthesis?
a. The light-independent ("dark") reaction makes glucose from carbon dioxide (CO2)
and water, using energy trapped by the light-dependent reaction
b. Light-excited electrons in chlorophyll provide the energy for ATP production
c. The light-independent ("dark") reaction converts light energy to chemical energy
stored in ATP
d. The light-dependent reaction captures electrons in NADPH, which are used for
glucose synthesis in the light-independent ("dark") reaction
e. None of the above (all are true of photosynthesis)
- ANSWER C
In biological systems, anabolic and catabolic reactions are "coupled" (or linked) by:
a. Krebs cycle b. Glycolysis c. Photosynthesis
, d. Adenosine Triphosphate (ATP) e. The Electron Transport Chain
- ANSWER D
In the diagram below, which of the following is TRUE?
a. The NAD+ becomes reduced b. The organic molecule becomes reduced
c. Neither molecule is oxidized or reduced d. The NAD+ becomes oxidized
e. None of the above are true
(Image is an organic molecule that includes two hydrogen atoms. Arrows pointing from
the hydrogen atoms to NAD+ coenzyme (electron carrier) then arrow to organic
molecule with no hydrogen next to an illustration of NADH + H+)
- ANSWER A. Reduction is addition of electrons to a molecule
The complete aerobic respiration of glucose yields far more energy stored in ATP than
glycolysis alone for all of the following reasons EXCEPT:
a. Krebs cycle generates some additional ATP through substrate-level phosphorylation
b. Glycolysis only partially oxidizes the glucose molecule to pyruvic acid
c. Electron transport chain (terminal respiratory pathway) produces many ATPs through
oxidative phosphorylation using electron carrier molecules (NADH and FADH2)
d. Krebs cycle generates reduced electron carrier molecules (NADH and FADH2)
e. None of the above (All are reasons that aerobic respiration yields more energy than
glycolysis alone)
- ANSWER E
Bacteria that grow best (optimally) at very high temperatures are called:
a. Mesophiles b. Hyperthermophiles c. Capnophiles d. Halophiles e. Psychrophiles -
ANSWER B
In the diagram at right, enzyme action has been stopped (prevented) by
binding of what to the active site?
a. noncompetitive inhibitor
b. coenzyme
c. competitive inhibitor
d. substrate
e. none of the above
(Diagram shows a something blocking a substrate from entering the active site of an
enzyme)
- ANSWER C. Competitive inhibitors compete with the normal substrate for the active
site of an enzyme
This figure shows the typical
growth pattern in culture for a(n):
a. Facultative anaerobe
b. Microaerophile
c. Obligate aerobe
d. Obligate anaerobe
e. None of the above
MATERIAL WITH VERIFIED ANSWERS
LATEST UPDATE NEW VERSION 2024-
2025 GRADED A.
You observe a cell through a microscope and see that it has mitochondria. To which
Domain of
organisms does it belong?
a. Bacteria b. Archaea c. Animalia (Animals) d. Eukarya
e. Cannot be determined from the information provided
- ANSWER D. Eukarya consist of animals, plants, fungi and protists
Which of the following is NOT true of ionic bonds?
a. They are formed due to the mutual attraction of cations and anions
b. Electrons are shared by atoms
c. They are weaker than covalent bonds
d. They are stronger than hydrogen bonds
e. None of the above (all of the above are true of ionic bonds)
- ANSWER B. Ionic bonds are formed when atoms gain or lose electrons in the outer
energy level
Which of the following statements is NOT true of biological organic molecules?
a. They're usually polymers formed from subunits (monomers)
b. Monomers are linked (bonded) together by hydrolysis ("water splitting")
c. Always contain hydrogen and carbon
d. Their atoms are mostly or entirely covalently bonded
e. None of the above (i.e., all of the above are true)
- ANSWER B. Hyrdrolysis is a decomposing reaction
Which of the following statements is NOT true?
a. Decomposition (degradation, catabolic) reactions are usually endergonic
b. Enzymes increase the probability that a chemical reaction will take place by lowering
the activation energy
c. Chemical reactions in living cells are catalyzed by enzymes
d. The energy required to cause a chemical reaction to occur is called the activation
energy
e. None of the above (all of these statements are true)
- ANSWER A. Decomposition reactions are usually exergonic, releasing energy
If a bacterial cell is placed in a hypertonic (hyperosmotic) solution:
a. Water moves through the plasma membrane into the cell
b. The cell undergoes osmotic lysis
,c. Water moves through the plasma membrane out of the cell, causing plasmolysis
d. There is no net movement of water either into or out of the cell
e. None of the above describes what happens in a hypertonic solution
- ANSWER C.
All of the following are correctly matched and can be found in bacteria EXCEPT:
a. Ribosomes - site of protein synthesis
b. Cell (plasma) membrane - encloses cytoplasm; phospholipid bilayer with proteins
c. Cell wall - contains peptidoglycan
d. Nucleus - membrane-bound organelle containing multiple chromosomes
e. None of the above (all are correctly matched and can be found in bacteria) -
ANSWER D. Bacteria are prokaryotes which do not have a nucleus
In the Gram stain, gram-positive bacteria are dark purple for all the following reasons
EXCEPT:
a. The counterstain (safranin) causes the purple color to develop
b. Thick peptidoglycan in the gram-positive cell wall prevents decolorization by alcohol
c. Crystal Violet is fixed inside the cell as a CV-iodine complex once iodine is added
d. The primary stain, Crystal Violet, is dark purple
e. None of the above (All are reasons that gram-positive bacteria are purple in the Gram
stain)
- ANSWER A. Safranin is a counterstain that is used to color the gram-negative bacteria
that lose their color after decolorization
Which of the following is NOT true about chemoheterotrophs?
a. Use organic compounds as a source of both carbon and energy
b. Can use light for energy and CO2 as a source of carbon
c. They are ultimately dependent on autotrophs to provide their carbon and energy
d. Oxidize organic compounds (e.g., glucose) to generate ATP
e. None of the above (All are true of chemoheterotrophs)
- ANSWER B Chemoheterotrophs are unable to utilize carbon dioxide to form their own
organic compounds
Which of the following is NOT true of photosynthesis?
a. The light-independent ("dark") reaction makes glucose from carbon dioxide (CO2)
and water, using energy trapped by the light-dependent reaction
b. Light-excited electrons in chlorophyll provide the energy for ATP production
c. The light-independent ("dark") reaction converts light energy to chemical energy
stored in ATP
d. The light-dependent reaction captures electrons in NADPH, which are used for
glucose synthesis in the light-independent ("dark") reaction
e. None of the above (all are true of photosynthesis)
- ANSWER C
In biological systems, anabolic and catabolic reactions are "coupled" (or linked) by:
a. Krebs cycle b. Glycolysis c. Photosynthesis
, d. Adenosine Triphosphate (ATP) e. The Electron Transport Chain
- ANSWER D
In the diagram below, which of the following is TRUE?
a. The NAD+ becomes reduced b. The organic molecule becomes reduced
c. Neither molecule is oxidized or reduced d. The NAD+ becomes oxidized
e. None of the above are true
(Image is an organic molecule that includes two hydrogen atoms. Arrows pointing from
the hydrogen atoms to NAD+ coenzyme (electron carrier) then arrow to organic
molecule with no hydrogen next to an illustration of NADH + H+)
- ANSWER A. Reduction is addition of electrons to a molecule
The complete aerobic respiration of glucose yields far more energy stored in ATP than
glycolysis alone for all of the following reasons EXCEPT:
a. Krebs cycle generates some additional ATP through substrate-level phosphorylation
b. Glycolysis only partially oxidizes the glucose molecule to pyruvic acid
c. Electron transport chain (terminal respiratory pathway) produces many ATPs through
oxidative phosphorylation using electron carrier molecules (NADH and FADH2)
d. Krebs cycle generates reduced electron carrier molecules (NADH and FADH2)
e. None of the above (All are reasons that aerobic respiration yields more energy than
glycolysis alone)
- ANSWER E
Bacteria that grow best (optimally) at very high temperatures are called:
a. Mesophiles b. Hyperthermophiles c. Capnophiles d. Halophiles e. Psychrophiles -
ANSWER B
In the diagram at right, enzyme action has been stopped (prevented) by
binding of what to the active site?
a. noncompetitive inhibitor
b. coenzyme
c. competitive inhibitor
d. substrate
e. none of the above
(Diagram shows a something blocking a substrate from entering the active site of an
enzyme)
- ANSWER C. Competitive inhibitors compete with the normal substrate for the active
site of an enzyme
This figure shows the typical
growth pattern in culture for a(n):
a. Facultative anaerobe
b. Microaerophile
c. Obligate aerobe
d. Obligate anaerobe
e. None of the above
