BIOL 221 UPDATED EXAM COMPREHENSIVE
REVIEW 2026 COMPLETE QUESTIONS AND
CORRECT ANSWERS GRADED A+
◉ endocytosis to engulf nutrients.
Answer: Which of the following is a hallmark of protozoa, but NOT of
bacteria?
A. life in extreme environments
B. endocytosis to engulf nutrients
C. saprophytic lifestyle
D. the presence of a cytoskeleton
E. two cell forms - yeast and mold
◉ They cannot infect humans..
Answer: These viruses infect the bacterium Escherichia coli. Which
of thefollowing MUST also be true?
A. They have a lipid envelope.
B. They contain no protein.
C. They cannot infect humans.
D. The viruses are prokaryotes.
,E. Their diameter (white line) is less than 1 nanometer.
◉ protein only.
Answer: Prions are infectious agents that contain
A. protein only
B. RNA only
C. RNA and protein
D. DNA and protein
E. RNA, DNA and protein
◉ If you change a variable in an experiment, you know how the
results will change..
Answer: We said in an early lecture that science should be
"predictive." What does this mean?
A. If you repeat the same experiment, you get the same results.
B. You know in advance which experiments will work and which
won't.
C. If you change a variable in an experiment, you know how the
results will change.
D. You can try a completely new experiment and know in advance
what the results will be.
,E. You can deduce how a biological system will evolve in the future.
◉ Only Bacteria have peptidoglycan in their cell structures..
Answer: Which of the following correctly describes comparisons
between Bacteria, Eukaryotes andArchaea?
A. Archaea have no protein, just RNA.
B. Only Eukaryotes have a cytoskeletal protein network within their
cells.
C. Bacteria and Eukaryotes have a nucleus; Archaea don't.
D. Only Bacteria have peptidoglycan in their cell structures.
E. Eukaryotes are a much more diverse group than the other two.
◉ Bacteriophage can't infect humans..
Answer: Last semester, when he was working with bacteriophage in
the lab, a student came to me and saidhis doctor had told him he had
a viral infection. He was pretty sure he had acquired the infection
fromthe bacteriophage he was working with in lab. What would you
have told him?
A. Bacteriophage are not viruses.
B. Bacteriophage can't infect humans.
C. Bacteriophage are dimorphic. We don't use the human variety in
lab.
, D. Bacteriophage don't have DNA, so the infection shouldn't be too
serious.
E. The student should work on his sterile technique so something
like this won't happen again.
◉ a type of fungus.
Answer: The pictures shown here represent the same organism at
different stages in its lifecycle. What is the organism?
A. a type of algae
B. a type of fungus
C. a protozoan
D. a bacteriophage
E. a type of archaea
◉ an enveloped virus.
Answer: A structure that is 50 nanometers in diameter and is
composed only of protein, RNA and lipidwould most likely be an
example of which of the following?
A. an enveloped virus
B. a naked virus
C. a viroid
REVIEW 2026 COMPLETE QUESTIONS AND
CORRECT ANSWERS GRADED A+
◉ endocytosis to engulf nutrients.
Answer: Which of the following is a hallmark of protozoa, but NOT of
bacteria?
A. life in extreme environments
B. endocytosis to engulf nutrients
C. saprophytic lifestyle
D. the presence of a cytoskeleton
E. two cell forms - yeast and mold
◉ They cannot infect humans..
Answer: These viruses infect the bacterium Escherichia coli. Which
of thefollowing MUST also be true?
A. They have a lipid envelope.
B. They contain no protein.
C. They cannot infect humans.
D. The viruses are prokaryotes.
,E. Their diameter (white line) is less than 1 nanometer.
◉ protein only.
Answer: Prions are infectious agents that contain
A. protein only
B. RNA only
C. RNA and protein
D. DNA and protein
E. RNA, DNA and protein
◉ If you change a variable in an experiment, you know how the
results will change..
Answer: We said in an early lecture that science should be
"predictive." What does this mean?
A. If you repeat the same experiment, you get the same results.
B. You know in advance which experiments will work and which
won't.
C. If you change a variable in an experiment, you know how the
results will change.
D. You can try a completely new experiment and know in advance
what the results will be.
,E. You can deduce how a biological system will evolve in the future.
◉ Only Bacteria have peptidoglycan in their cell structures..
Answer: Which of the following correctly describes comparisons
between Bacteria, Eukaryotes andArchaea?
A. Archaea have no protein, just RNA.
B. Only Eukaryotes have a cytoskeletal protein network within their
cells.
C. Bacteria and Eukaryotes have a nucleus; Archaea don't.
D. Only Bacteria have peptidoglycan in their cell structures.
E. Eukaryotes are a much more diverse group than the other two.
◉ Bacteriophage can't infect humans..
Answer: Last semester, when he was working with bacteriophage in
the lab, a student came to me and saidhis doctor had told him he had
a viral infection. He was pretty sure he had acquired the infection
fromthe bacteriophage he was working with in lab. What would you
have told him?
A. Bacteriophage are not viruses.
B. Bacteriophage can't infect humans.
C. Bacteriophage are dimorphic. We don't use the human variety in
lab.
, D. Bacteriophage don't have DNA, so the infection shouldn't be too
serious.
E. The student should work on his sterile technique so something
like this won't happen again.
◉ a type of fungus.
Answer: The pictures shown here represent the same organism at
different stages in its lifecycle. What is the organism?
A. a type of algae
B. a type of fungus
C. a protozoan
D. a bacteriophage
E. a type of archaea
◉ an enveloped virus.
Answer: A structure that is 50 nanometers in diameter and is
composed only of protein, RNA and lipidwould most likely be an
example of which of the following?
A. an enveloped virus
B. a naked virus
C. a viroid
