BIOL251 / BIOL 251 Module & Lab 3: (Latest
Update ) Human Anatomy &
Physiology I with Lab | Questions & Answers |
Grade A 100% Correct - Portage Learning
A virus remains undetectable in the body for a period and then reactivates later, such as in
herpes simplex virus or varicella-zoster virus. What is this type of infection called?
A. Acute infection
B. Chronic infection
C. Latent infection
D. Opportunistic infection
Answer: C
Rationale:
A latent infection is one in which the virus remains dormant within host cells and is not
actively detectable. It can later reactivate, as seen in herpes simplex virus and varicella-
zoster virus (which causes shingles). The virus is present but not actively replicating during
latency.
An organism measuring 80 µm × 600 µm is found in the gut of a Red Sea surgeonfish. Based
on its size alone, how should it be classified?
A. Virus
B. Prokaryote
C. Eukaryote
D. Prion
Answer: C
Rationale:
The size of the organism is far larger than bacteria or viruses. Prokaryotes are typically much
smaller (1–5 µm). A structure of this size strongly suggests a eukaryotic organism, which can
reach large cellular dimensions due to internal compartmentalization.
Human immunodeficiency virus (HIV) requires which enzymes for replication?
,A. DNA polymerase and helicase
B. Reverse transcriptase and integrase
C. RNA polymerase and ligase
D. Protease and primase
Answer: B
Rationale:
HIV is a retrovirus. It uses reverse transcriptase to convert RNA into DNA and integrase to
insert viral DNA into the host genome. These enzymes are essential for viral replication and
persistence.
A bacterial cell is placed in a 10% NaCl solution. What is the expected effect?
A. Water enters the cell, causing swelling
B. No change occurs
C. Water moves out, causing plasmolysis
D. Cell undergoes lysis
Answer: C
Rationale:
A 10% NaCl solution is hypertonic relative to bacterial cytoplasm. Water moves out of the
cell via osmosis, causing shrinkage of the cytoplasm and separation of the membrane from
the cell wall (plasmolysis), inhibiting growth.
Which organelle is incorrectly matched with its function?
A. Ribosome – protein synthesis
B. Golgi apparatus – protein modification and packaging
C. Mitochondria – ATP production
D. Golgi apparatus – protein synthesis
Answer: D
Rationale:
Protein synthesis occurs at ribosomes, not the Golgi apparatus. The Golgi modifies, sorts,
and packages proteins for transport. Therefore, assigning protein synthesis to the Golgi is
incorrect.
Which of the following best describes prokaryotes?
A. Cells with a nucleus and membrane-bound organelles
B. Unicellular organisms with complex organelles
,C. Bacteria and archaea lacking a nucleus
D. Multicellular organisms only
Correct answer: C
Rationale: Prokaryotes include bacteria and archaea. They lack a nucleus and membrane-
bound organelles.
Which group includes unicellular prokaryotes that live in extreme environments?
A. Bacteria
B. Fungi
C. Archaea
D. Protozoa
Correct answer: C
Rationale: Archaea are prokaryotes adapted to extreme environments such as high heat or
salinity.
Which organisms are eukaryotic and mostly unicellular?
A. Viruses and bacteria
B. Fungi, protozoa, algae
C. Archaea and bacteria
D. Plants and animals only
Correct answer: B
Rationale: Fungi, protozoa, and algae can be unicellular eukaryotes.
Which statement best defines a pathogen?
A. A beneficial microbe in the gut
B. A disease-causing organism
C. A virus only
D. A non-living particle
Correct answer: B
Rationale: Pathogens are organisms that cause disease in a host.
What is a biofilm?
, A. Single bacteria floating freely
B. Viral replication structure
C. Microbial community attached to surfaces
D. Dead bacterial debris
Correct answer: C
Rationale: Biofilms are structured communities of microbes that adhere to surfaces and are
often resistant to treatment.
Who first proposed that all living things are made of cells?
A. Louis Pasteur
B. Robert Hooke
C. Robert Koch
D. Antonie van Leeuwenhoek
Correct answer: B
Rationale: Robert Hooke developed early cell theory concepts.
Who first observed living microorganisms?
A. Virchow
B. Leeuwenhoek
C. Pasteur
D. Semmelweis
Correct answer: B
Rationale: Antonie van Leeuwenhoek used early microscopes to observe microbes.
What did the theory of spontaneous generation propose?
A. Life comes only from preexisting life
B. Life arises from nonliving matter
C. Cells divide by mitosis
D. Viruses evolve from bacteria
Correct answer: B
Rationale: It incorrectly suggested life could appear from nonliving material.
Which scientist disproved spontaneous generation using swan-neck flask experiments?
Update ) Human Anatomy &
Physiology I with Lab | Questions & Answers |
Grade A 100% Correct - Portage Learning
A virus remains undetectable in the body for a period and then reactivates later, such as in
herpes simplex virus or varicella-zoster virus. What is this type of infection called?
A. Acute infection
B. Chronic infection
C. Latent infection
D. Opportunistic infection
Answer: C
Rationale:
A latent infection is one in which the virus remains dormant within host cells and is not
actively detectable. It can later reactivate, as seen in herpes simplex virus and varicella-
zoster virus (which causes shingles). The virus is present but not actively replicating during
latency.
An organism measuring 80 µm × 600 µm is found in the gut of a Red Sea surgeonfish. Based
on its size alone, how should it be classified?
A. Virus
B. Prokaryote
C. Eukaryote
D. Prion
Answer: C
Rationale:
The size of the organism is far larger than bacteria or viruses. Prokaryotes are typically much
smaller (1–5 µm). A structure of this size strongly suggests a eukaryotic organism, which can
reach large cellular dimensions due to internal compartmentalization.
Human immunodeficiency virus (HIV) requires which enzymes for replication?
,A. DNA polymerase and helicase
B. Reverse transcriptase and integrase
C. RNA polymerase and ligase
D. Protease and primase
Answer: B
Rationale:
HIV is a retrovirus. It uses reverse transcriptase to convert RNA into DNA and integrase to
insert viral DNA into the host genome. These enzymes are essential for viral replication and
persistence.
A bacterial cell is placed in a 10% NaCl solution. What is the expected effect?
A. Water enters the cell, causing swelling
B. No change occurs
C. Water moves out, causing plasmolysis
D. Cell undergoes lysis
Answer: C
Rationale:
A 10% NaCl solution is hypertonic relative to bacterial cytoplasm. Water moves out of the
cell via osmosis, causing shrinkage of the cytoplasm and separation of the membrane from
the cell wall (plasmolysis), inhibiting growth.
Which organelle is incorrectly matched with its function?
A. Ribosome – protein synthesis
B. Golgi apparatus – protein modification and packaging
C. Mitochondria – ATP production
D. Golgi apparatus – protein synthesis
Answer: D
Rationale:
Protein synthesis occurs at ribosomes, not the Golgi apparatus. The Golgi modifies, sorts,
and packages proteins for transport. Therefore, assigning protein synthesis to the Golgi is
incorrect.
Which of the following best describes prokaryotes?
A. Cells with a nucleus and membrane-bound organelles
B. Unicellular organisms with complex organelles
,C. Bacteria and archaea lacking a nucleus
D. Multicellular organisms only
Correct answer: C
Rationale: Prokaryotes include bacteria and archaea. They lack a nucleus and membrane-
bound organelles.
Which group includes unicellular prokaryotes that live in extreme environments?
A. Bacteria
B. Fungi
C. Archaea
D. Protozoa
Correct answer: C
Rationale: Archaea are prokaryotes adapted to extreme environments such as high heat or
salinity.
Which organisms are eukaryotic and mostly unicellular?
A. Viruses and bacteria
B. Fungi, protozoa, algae
C. Archaea and bacteria
D. Plants and animals only
Correct answer: B
Rationale: Fungi, protozoa, and algae can be unicellular eukaryotes.
Which statement best defines a pathogen?
A. A beneficial microbe in the gut
B. A disease-causing organism
C. A virus only
D. A non-living particle
Correct answer: B
Rationale: Pathogens are organisms that cause disease in a host.
What is a biofilm?
, A. Single bacteria floating freely
B. Viral replication structure
C. Microbial community attached to surfaces
D. Dead bacterial debris
Correct answer: C
Rationale: Biofilms are structured communities of microbes that adhere to surfaces and are
often resistant to treatment.
Who first proposed that all living things are made of cells?
A. Louis Pasteur
B. Robert Hooke
C. Robert Koch
D. Antonie van Leeuwenhoek
Correct answer: B
Rationale: Robert Hooke developed early cell theory concepts.
Who first observed living microorganisms?
A. Virchow
B. Leeuwenhoek
C. Pasteur
D. Semmelweis
Correct answer: B
Rationale: Antonie van Leeuwenhoek used early microscopes to observe microbes.
What did the theory of spontaneous generation propose?
A. Life comes only from preexisting life
B. Life arises from nonliving matter
C. Cells divide by mitosis
D. Viruses evolve from bacteria
Correct answer: B
Rationale: It incorrectly suggested life could appear from nonliving material.
Which scientist disproved spontaneous generation using swan-neck flask experiments?
