©Jason MacConnell 2025 ALL RIGHTS RESERVED.
Mcb Exam Questions With Correct Answers
A+
1. The gastrointestinal tract has both a long tube that nutrients traverse from mouth to anus and
accessory organs that aid in food digestion. From the following list of organs in the digestive
system, identify the mismatch.
A. Rectum; part of the digestive tube
B. Liver; part of the digestive tube
C. Pharynx; part of the digestive tube
D. Appendix; accessory organ
E. Salivary glands; accessory organ - Answer✔B
Most of the bacteria involved in periodontal disease are obligate (strict) anaerobes. Explain why
this is the case.
A. Mouthwashes and toothpaste destroy most of the strict aerobes that are found on teeth.
B. The oral cavity is a low oxygen environment.
C. The crevice between the gingiva and the tooth is low in oxygen.
D. Sugar and other carbohydrates used by the oral bacteria can be more easily consumed
anaerobically. - Answer✔c
Which of the following groups of microorganisms is not found among the normal gut
microbiota?
A. Firmicutes (Streptococcus, Staphylococcus, Clostridium, Bacillus)
, ©Jason MacConnell 2025 ALL RIGHTS RESERVED.
B. Protozoa (Entamoeba, Trichomonas)
C. Enterics (Escherichia, Enterobacter)
D. Spirilla (Leptospira, Borrelia)
E. Fungi (Candida) - Answer✔D
Which organ of the gastrointestinal tract has a large commensal population of microorganisms?
A. Pancreas
B. Liver
C. Salivary glands
D. Small intestine
E. Large intestine - Answer✔E
E. coli O157:H7 secretes shiga exotoxin.
F or T - Answer✔true
Antibiotics are used to treat diarrhea caused by shiga toxin-producing E. coli.
f or t - Answer✔false
Salmonella are ______.
A. methane producers
B. motile
C. gram-positive bacilli
D. lactose fermenters
, ©Jason MacConnell 2025 ALL RIGHTS RESERVED.
E. All of the choices are correct. - Answer✔B
The causative organism for mumps is ______.
A. Vibrio cholerae
B. Corynebacterium diphtheriae
C. Morbillivirus
D. Paramyxovirus
Streptococcus pyogenes - Answer✔D
Orchitis and epididymitis are seen in young, adult males as a complication of ______.
A. hepatitis
B. tapeworm infestation
C. mumps
gingivitis - Answer✔C
53. Giardiasis involves
A. a protozoan that does not form cysts.
B. infection of the large intestine.
Mcb Exam Questions With Correct Answers
A+
1. The gastrointestinal tract has both a long tube that nutrients traverse from mouth to anus and
accessory organs that aid in food digestion. From the following list of organs in the digestive
system, identify the mismatch.
A. Rectum; part of the digestive tube
B. Liver; part of the digestive tube
C. Pharynx; part of the digestive tube
D. Appendix; accessory organ
E. Salivary glands; accessory organ - Answer✔B
Most of the bacteria involved in periodontal disease are obligate (strict) anaerobes. Explain why
this is the case.
A. Mouthwashes and toothpaste destroy most of the strict aerobes that are found on teeth.
B. The oral cavity is a low oxygen environment.
C. The crevice between the gingiva and the tooth is low in oxygen.
D. Sugar and other carbohydrates used by the oral bacteria can be more easily consumed
anaerobically. - Answer✔c
Which of the following groups of microorganisms is not found among the normal gut
microbiota?
A. Firmicutes (Streptococcus, Staphylococcus, Clostridium, Bacillus)
, ©Jason MacConnell 2025 ALL RIGHTS RESERVED.
B. Protozoa (Entamoeba, Trichomonas)
C. Enterics (Escherichia, Enterobacter)
D. Spirilla (Leptospira, Borrelia)
E. Fungi (Candida) - Answer✔D
Which organ of the gastrointestinal tract has a large commensal population of microorganisms?
A. Pancreas
B. Liver
C. Salivary glands
D. Small intestine
E. Large intestine - Answer✔E
E. coli O157:H7 secretes shiga exotoxin.
F or T - Answer✔true
Antibiotics are used to treat diarrhea caused by shiga toxin-producing E. coli.
f or t - Answer✔false
Salmonella are ______.
A. methane producers
B. motile
C. gram-positive bacilli
D. lactose fermenters
, ©Jason MacConnell 2025 ALL RIGHTS RESERVED.
E. All of the choices are correct. - Answer✔B
The causative organism for mumps is ______.
A. Vibrio cholerae
B. Corynebacterium diphtheriae
C. Morbillivirus
D. Paramyxovirus
Streptococcus pyogenes - Answer✔D
Orchitis and epididymitis are seen in young, adult males as a complication of ______.
A. hepatitis
B. tapeworm infestation
C. mumps
gingivitis - Answer✔C
53. Giardiasis involves
A. a protozoan that does not form cysts.
B. infection of the large intestine.
