BIOL 221 UPDATED EXAM CERTIFICATION TEST
2026 QUESTIONS AND VERIFIED ANSWERS
ALREADY PASSED
◉ Viruses that infect bacteria cannot infect humans.
Answer: Which of the following statements about viruses is true?
A. They have an active chemical metabolism.
B. Viruses that infect bacteria cannot infect humans.
C. They have only RNA, no protein.
D. They cannot infect bacteria.
E. They are usually surrounded by a lipid envelope.
◉ Infectious proteins with no nucleic acid.
Answer: What are prions?
A. Infectious proteins with no nucleic acid.
B. Very tiny virus-like particles.
C. Infectious RNA with no protein.
D. Peptidoglycan particles that affect the immune system.
E. Small cells that lack a cell membrane.
,◉ as long as no living organisms enter a solution, it can be kept
sterile indefinitely.
Answer: Taken together, the experiments of Pasteur, Tyndall and
Koch demonstrated that...
A. some bacteria cannot be killed
B. as long as air can be kept out, a solution can be kept sterile
C. as long as no living organisms enter a solution, it can be kept
sterile indefinitely
D. sometimes an experiment must be repeated for it to work right
E. some forms of bacteria are not living organisms
◉ The virus preparation might be contaminated with a few live
bacterial cells..
Answer: There is much interest in using bacteriophages to kill the
bacteria that cause infectious diseases inhumans. Which of the
following is a valid concern about such therapy?
A. The bacterial viruses might also infect humans.
B. The bacterial viruses might carry bacterial DNA into human cells.
C. Bacterial viruses might mutate into uncontrollable "superbugs."
D. The virus preparation might be contaminated with a few live
bacterial cells.
,E. The viruses might evolve into new bacterial cells.
◉ small pieces of RNA without a protein coat.
Answer: Viroids are...
A. small virus-like particles
B. small pieces of RNA without a protein coat
C. empty protein coats without any nucleic acid
D. infectious proteins that serve as folding templates for other
proteins
E. another name for plant viruses
◉ a cell membrane.
Answer: Archaea have...
A. a nucleus
B. a cell membrane
C. peptidoglycan
D. chloroplasts
E. phosphotransferase systems
◉ only in media that came in contact with other bacteria.
, Answer: In Pasteur's famous experiment that finally disproved
spontaneous generation, bacteria grew
A. only in the flasks with a swan neck
B. only in media that came in contact with air
C. only in media that came in contact with other bacteria
D. only once the media had been boiled
E. in all flasks, regardless of how they were treated experimentally
◉ the media he was trying to sterilize contained endospores.
Answer: Tyndall repeated the same experiment, but got different
results. This was because
A. he didn't do the experiment right
B. he used different flasks than Pasteur
C. he was working in England, but Pasteur was working in France
D. he didn't boil the flasks for as long a time as Pasteur did
E. the media he was trying to sterilize contained endospores
◉ Eukaryotes have a nucleus surrounded by a nuclear membrane..
Answer: Which of the following is currently (2008) believed to be a
major difference between prokaryotesand eukaryotes?
2026 QUESTIONS AND VERIFIED ANSWERS
ALREADY PASSED
◉ Viruses that infect bacteria cannot infect humans.
Answer: Which of the following statements about viruses is true?
A. They have an active chemical metabolism.
B. Viruses that infect bacteria cannot infect humans.
C. They have only RNA, no protein.
D. They cannot infect bacteria.
E. They are usually surrounded by a lipid envelope.
◉ Infectious proteins with no nucleic acid.
Answer: What are prions?
A. Infectious proteins with no nucleic acid.
B. Very tiny virus-like particles.
C. Infectious RNA with no protein.
D. Peptidoglycan particles that affect the immune system.
E. Small cells that lack a cell membrane.
,◉ as long as no living organisms enter a solution, it can be kept
sterile indefinitely.
Answer: Taken together, the experiments of Pasteur, Tyndall and
Koch demonstrated that...
A. some bacteria cannot be killed
B. as long as air can be kept out, a solution can be kept sterile
C. as long as no living organisms enter a solution, it can be kept
sterile indefinitely
D. sometimes an experiment must be repeated for it to work right
E. some forms of bacteria are not living organisms
◉ The virus preparation might be contaminated with a few live
bacterial cells..
Answer: There is much interest in using bacteriophages to kill the
bacteria that cause infectious diseases inhumans. Which of the
following is a valid concern about such therapy?
A. The bacterial viruses might also infect humans.
B. The bacterial viruses might carry bacterial DNA into human cells.
C. Bacterial viruses might mutate into uncontrollable "superbugs."
D. The virus preparation might be contaminated with a few live
bacterial cells.
,E. The viruses might evolve into new bacterial cells.
◉ small pieces of RNA without a protein coat.
Answer: Viroids are...
A. small virus-like particles
B. small pieces of RNA without a protein coat
C. empty protein coats without any nucleic acid
D. infectious proteins that serve as folding templates for other
proteins
E. another name for plant viruses
◉ a cell membrane.
Answer: Archaea have...
A. a nucleus
B. a cell membrane
C. peptidoglycan
D. chloroplasts
E. phosphotransferase systems
◉ only in media that came in contact with other bacteria.
, Answer: In Pasteur's famous experiment that finally disproved
spontaneous generation, bacteria grew
A. only in the flasks with a swan neck
B. only in media that came in contact with air
C. only in media that came in contact with other bacteria
D. only once the media had been boiled
E. in all flasks, regardless of how they were treated experimentally
◉ the media he was trying to sterilize contained endospores.
Answer: Tyndall repeated the same experiment, but got different
results. This was because
A. he didn't do the experiment right
B. he used different flasks than Pasteur
C. he was working in England, but Pasteur was working in France
D. he didn't boil the flasks for as long a time as Pasteur did
E. the media he was trying to sterilize contained endospores
◉ Eukaryotes have a nucleus surrounded by a nuclear membrane..
Answer: Which of the following is currently (2008) believed to be a
major difference between prokaryotesand eukaryotes?
