Q: Which of the following equations best represents the conversion of sucrose to lactic acid by Streptococcus mutans, contributing to dental caries?

$$\text{C}_{12}\text{H}_{22}\text{O}_{11} + \text{H}_2\text{O} \rightarrow 2 \text{C}_6\text{H}_{12}\text{O}_6 \rightarrow 4 \text{CH}_3\text{CH}(OH)\text{COOH}$$

Question 1

Which of the following best describes the primary function of lymph nodes in the lymphatic system?

Accepted Answer

They filter microorganisms and infectious agents from lymph, containing fixed macrophages, B cells, and T cells.

Question 2

A patient develops septic shock after a Gram-negative bacterial infection. Which component of the bacteria is most responsible for the drop in blood pressure observed in this condition?

Accepted Answer

Lipopolysaccharide (LPS)

Question 3

Which of the following is a major risk when treating Gram-negative sepsis with antibiotics?

Accepted Answer

Antibiotics can worsen the condition by causing the release of more endotoxins.

Question 4

Which protozoan disease of the cardiovascular system is transmitted by mosquitoes and is characterized by cycles of fever and chills due to the rupture of red blood cells?

Accepted Answer

Malaria

Question 5

A patient presents with swollen lymph nodes, fever, and fatigue. Laboratory tests confirm infection with Epstein-Barr virus (EBV). Which disease is most likely diagnosed?

Accepted Answer

Infectious mononucleosis

Question 6

Which of the following bacteria is most commonly associated with dental caries due to its ability to convert sucrose to lactic acid and dextran?

Accepted Answer

Streptococcus mutans

Question 7

A patient develops severe diarrhea after prolonged antibiotic use in a healthcare setting. Which organism is most likely responsible?

Accepted Answer

Clostridium difficile

Question 8

Which hepatitis virus is transmitted primarily via the oral-fecal route and is associated with acute, self-limiting infection?

Accepted Answer

Hepatitis A virus (HAV)

Question 9

Which sexually transmitted infection is characterized by painful genital ulcers and is caused by Haemophilus ducreyi?

Accepted Answer

Chancroid

Question 10

A newborn develops conjunctivitis after passing through the birth canal of a mother with an untreated sexually transmitted infection. Which organism is most likely responsible for this condition known as ophthalmia neonatorum?

Accepted Answer

Neisseria gonorrhoeae

Question 11

Which of the following is a common sign of bacterial vaginosis?

Accepted Answer

Copious frothy discharge with a fishy odor

Question 12

Which of the following is a major complication of pelvic inflammatory disease (PID) if left untreated?

Accepted Answer

Infertility or ectopic pregnancy

Question 13

Which virus is associated with cervical cancer and is preventable by vaccination?

Accepted Answer

Human papillomavirus (HPV)

Question 14

Which of the following best explains why the stomach contains relatively few microorganisms compared to other parts of the digestive tract?

Accepted Answer

High acid production

Question 15

A patient presents with profuse, frothy, greenish-yellow vaginal discharge with a foul odor. Which protozoan is most likely responsible?

Accepted Answer

Trichomonas vaginalis

Question 16

Which of the following equations best represents the conversion of sucrose to lactic acid by Streptococcus mutans, contributing to dental caries?

Accepted Answer

$$	ext{C}_{12}	ext{H}_{22}	ext{O}_{11} + 	ext{H}_2	ext{O} ightarrow 2 	ext{C}_6	ext{H}_{12}	ext{O}_6 ightarrow 4 	ext{CH}_3	ext{CH}(OH)	ext{COOH}$$

Question 17

Which of the following is the most common cause of urinary tract infections (UTIs)?

Accepted Answer

Escherichia coli

Question 18

Which of the following best describes the pathogenesis of hemolytic uremic syndrome (HUS) following infection with EHEC O157:H7?

Accepted Answer

Shiga-like toxin damages endothelial cells in the kidneys, leading to renal failure.

Question 19

Which of the following is a key difference between Gram-positive and Gram-negative sepsis?

Accepted Answer

Gram-negative sepsis is primarily due to endotoxins (LPS), while Gram-positive sepsis is due to exotoxins.

Infectious Diseases: Cardiovascular, GI Tract, and Urogenital Tract Infections (MCB2000 Module 11 Study Notes)

Study Guide - Practice Questions

Study Guide - Flashcards