BIO 116 Final ACTUAL UPDATED Exam
Questions and CORRECT Answers
Which of the following is an example of differential regulation
A. Muscle cells have larger amounts of the protein myosin than other cells
B. Neurons have the enzymes to make acetylcholine, other cells do not
C. Most mammals produce lactase enzyme for a period after birth, but not after they are weened
D. All of the above - CORRECT ANSWER D. All of the above
In which of the following cells will the enzymes that synthesize tryptophan NOT be present? The
trp operon is a repressible operon.
I. Cells where no tryptophan is present
II. Cell exposed to tryptophan
III. Cell from mutant strain where trp repressor has been deleted and no tryptophan is present
IV. Cell from mutant strain where trp repressor has been deleted and is exposed to tryptophan -
CORRECT ANSWER II. Cells exposed to tryptophan
How does acetylation of histone make transcription easier in certain parts of the genone?
A. Acetylated histones activate RNA polymerase allowing it to transcribe genes
B. Acetylated histones more readily bind to the TATA box
C. Acetylated histones are less sticky, spreading out the nucleosomes and making the DNA
easier to access
D. DNA is wrapped more tightly around the acetylated histones, holding that part of the DNA in
place for transcription - CORRECT ANSWER C. Acetylated histones are less sticky,
spreading out the nucleosomes and making the DNA easier to access
Why would a bacterium regulate in the genes for enzymes involved in lactose metabolism with
an inducible operon?
A. The enzymes are only needed if lactose is present
B. The enzymes are only needed when lactose levels are low
,C. The enzymes are constitutive
D. The genes have a high mutation rate if they are expressed too much
E. The genes for lactose metabolism are not regulated - CORRECT ANSWER A. The
enzymes are only needed if lactose is present
What are modifications to the DNA or chromosomes that affect gene expression but do not
change the DNA sequence?
A. Activators
B. Epigenetic modifications
C. Mutations
D. Repressors
E. This is not possible - CORRECT ANSWER B. Epigenetic modifications
Which of the following is NOT a correct statement about DNA methylation?
A. It usually prevents or reduces transcription
B. It is the addition of methyl groups to cytosines in the DNA
C. It's used to mark and silence the maternal or paternal gene copy in some genes
D. It is erased every time a cell replicates its DNA to divide - CORRECT ANSWER D. It
is erased every time a cell replicates its DNA to divide
What will a particular activator regulatory transcription factor in eukaryotes bind to?
A. an enhancer sequence in the regulatory region in front of a few specific genes
B. An enhancer sequence in the regulatory region in front of all genes
C. The TATA box in the promotor region of a few specific genes
D. The TATA box in the promoter region of all genes - CORRECT ANSWER A. An
enhancer sequence in the regulatory region in front of a few specific genes
Why would it be incorrect for a researcher to state that they have found the transcription factor
that controls the expression of a particular gene?
A. Expression of a gene is usually controlled by multiple transcription factors
,B. Genes are always active, there is no need to control their transcription
C. Transcription factors do not bind to DNA
D. Transcription factors control the splicing of RNA, not gene expression - CORRECT
ANSWER A. Expression of a gene is usually controlled by multiple transcription factors
Which of the following is one of the main reasons an mRNA molecule might be alternatively
spliced?
A. To control how long an mRNA persists before it degraded and can no longer be translated
B. To make all of the enzymes in a metabolic pathway
C. To make different versions of a protein for different tissues/parts of the body
D. To remove mutated sequences before translation
E. A and B - CORRECT ANSWER C. To make different versions of a protein for
different tissues/parts of the body
Why do gram-negative bacteria tend to be less susceptible to antibodies than gram-positive
bacteria?
A. The thin wall of gram-negative bacteria means it is critical and not a good target for
antibodies
B. Gram negative bacteria have thicker cell wall that protects them from antibodies
C. The additional plasma membrane gram-negative bacteria have outside of the cell wall protects
them from antibodies
D. Lipopolysaccharides destroy the antibodies before they reach the bacteria
E. None of the above, gram-negative bacteria are actually more susceptible - CORRECT
ANSWER C. The additional plasma membrane gram-negative bacteria have outside of the
cell wall protects them from antibiotics
During which phase in the growth of bacterial colony are he bacterial most likely to engage in
group or high-density behaviors?
A. Death Phase
B. Lag Phase
C. Logarithmic phase
, D. Stationary phase - CORRECT ANSWER D. Stationary phase
What is the process that enables bacteria to determine when they should switch to the group of
high-density behaviors?
A. Binary fission
B. Conjugation
C. Operon activation
D. Quorum sensing
E. Resistance - CORRECT ANSWER D. Quorum sensing
When do bacteria usually produce endospores?
A. When there is a decline in the quality or resources of the environment
B. When they are threatened by predators
C. When they reproduce
D. All of the above - CORRECT ANSWER D. All of the above
Suppose scientists test a new antibiotic against individual gram-positive bacterial cells, and find
it to be highly effective in killing the bacteria. However, when they try to use the antibiotic to
treat an infection by the bacteria in a patient, they find it has limited effect. How can you explain
this?
A. The bacteria has become Gram-negative as part of the infective process
B. Bacteria in high-density population produce thicker pepodoglycan cell walls that protect them
from antibiotics
C. The infection is caused by the endospores of the bacteria, which are more resistance
D. The infection has a high density of bacteria, and they are producing a biofilm the keeping the
antibiotic from reaching the bacteria
E. the lipopolysaccharides are inactivating the antibiotics before they reach the bacteria -
CORRECT ANSWER D. The infection has a high density of bacteria, and they are
producing a biofilm the keeping the antibiotic from reaching the bacteria
Which of the following characteristics is true of endotoxins produced by bacteria?
Questions and CORRECT Answers
Which of the following is an example of differential regulation
A. Muscle cells have larger amounts of the protein myosin than other cells
B. Neurons have the enzymes to make acetylcholine, other cells do not
C. Most mammals produce lactase enzyme for a period after birth, but not after they are weened
D. All of the above - CORRECT ANSWER D. All of the above
In which of the following cells will the enzymes that synthesize tryptophan NOT be present? The
trp operon is a repressible operon.
I. Cells where no tryptophan is present
II. Cell exposed to tryptophan
III. Cell from mutant strain where trp repressor has been deleted and no tryptophan is present
IV. Cell from mutant strain where trp repressor has been deleted and is exposed to tryptophan -
CORRECT ANSWER II. Cells exposed to tryptophan
How does acetylation of histone make transcription easier in certain parts of the genone?
A. Acetylated histones activate RNA polymerase allowing it to transcribe genes
B. Acetylated histones more readily bind to the TATA box
C. Acetylated histones are less sticky, spreading out the nucleosomes and making the DNA
easier to access
D. DNA is wrapped more tightly around the acetylated histones, holding that part of the DNA in
place for transcription - CORRECT ANSWER C. Acetylated histones are less sticky,
spreading out the nucleosomes and making the DNA easier to access
Why would a bacterium regulate in the genes for enzymes involved in lactose metabolism with
an inducible operon?
A. The enzymes are only needed if lactose is present
B. The enzymes are only needed when lactose levels are low
,C. The enzymes are constitutive
D. The genes have a high mutation rate if they are expressed too much
E. The genes for lactose metabolism are not regulated - CORRECT ANSWER A. The
enzymes are only needed if lactose is present
What are modifications to the DNA or chromosomes that affect gene expression but do not
change the DNA sequence?
A. Activators
B. Epigenetic modifications
C. Mutations
D. Repressors
E. This is not possible - CORRECT ANSWER B. Epigenetic modifications
Which of the following is NOT a correct statement about DNA methylation?
A. It usually prevents or reduces transcription
B. It is the addition of methyl groups to cytosines in the DNA
C. It's used to mark and silence the maternal or paternal gene copy in some genes
D. It is erased every time a cell replicates its DNA to divide - CORRECT ANSWER D. It
is erased every time a cell replicates its DNA to divide
What will a particular activator regulatory transcription factor in eukaryotes bind to?
A. an enhancer sequence in the regulatory region in front of a few specific genes
B. An enhancer sequence in the regulatory region in front of all genes
C. The TATA box in the promotor region of a few specific genes
D. The TATA box in the promoter region of all genes - CORRECT ANSWER A. An
enhancer sequence in the regulatory region in front of a few specific genes
Why would it be incorrect for a researcher to state that they have found the transcription factor
that controls the expression of a particular gene?
A. Expression of a gene is usually controlled by multiple transcription factors
,B. Genes are always active, there is no need to control their transcription
C. Transcription factors do not bind to DNA
D. Transcription factors control the splicing of RNA, not gene expression - CORRECT
ANSWER A. Expression of a gene is usually controlled by multiple transcription factors
Which of the following is one of the main reasons an mRNA molecule might be alternatively
spliced?
A. To control how long an mRNA persists before it degraded and can no longer be translated
B. To make all of the enzymes in a metabolic pathway
C. To make different versions of a protein for different tissues/parts of the body
D. To remove mutated sequences before translation
E. A and B - CORRECT ANSWER C. To make different versions of a protein for
different tissues/parts of the body
Why do gram-negative bacteria tend to be less susceptible to antibodies than gram-positive
bacteria?
A. The thin wall of gram-negative bacteria means it is critical and not a good target for
antibodies
B. Gram negative bacteria have thicker cell wall that protects them from antibodies
C. The additional plasma membrane gram-negative bacteria have outside of the cell wall protects
them from antibodies
D. Lipopolysaccharides destroy the antibodies before they reach the bacteria
E. None of the above, gram-negative bacteria are actually more susceptible - CORRECT
ANSWER C. The additional plasma membrane gram-negative bacteria have outside of the
cell wall protects them from antibiotics
During which phase in the growth of bacterial colony are he bacterial most likely to engage in
group or high-density behaviors?
A. Death Phase
B. Lag Phase
C. Logarithmic phase
, D. Stationary phase - CORRECT ANSWER D. Stationary phase
What is the process that enables bacteria to determine when they should switch to the group of
high-density behaviors?
A. Binary fission
B. Conjugation
C. Operon activation
D. Quorum sensing
E. Resistance - CORRECT ANSWER D. Quorum sensing
When do bacteria usually produce endospores?
A. When there is a decline in the quality or resources of the environment
B. When they are threatened by predators
C. When they reproduce
D. All of the above - CORRECT ANSWER D. All of the above
Suppose scientists test a new antibiotic against individual gram-positive bacterial cells, and find
it to be highly effective in killing the bacteria. However, when they try to use the antibiotic to
treat an infection by the bacteria in a patient, they find it has limited effect. How can you explain
this?
A. The bacteria has become Gram-negative as part of the infective process
B. Bacteria in high-density population produce thicker pepodoglycan cell walls that protect them
from antibiotics
C. The infection is caused by the endospores of the bacteria, which are more resistance
D. The infection has a high density of bacteria, and they are producing a biofilm the keeping the
antibiotic from reaching the bacteria
E. the lipopolysaccharides are inactivating the antibiotics before they reach the bacteria -
CORRECT ANSWER D. The infection has a high density of bacteria, and they are
producing a biofilm the keeping the antibiotic from reaching the bacteria
Which of the following characteristics is true of endotoxins produced by bacteria?
