🦠 Microbiology Solved MCQs with Answers

Practice 1927 approved 🦠 Microbiology questions with verified answers from the 🧬 Medical Science subject for Pakistan exams.

1927 solved MCQs

Both Mycobacterium tuberculosis and Streptococcus pneumoniaeAnswer: are acquired by inhalation Cholera toxin is an A-B type toxin in which the B portions bind to a receptor on a host cell and the A portion enters the cell to causeAnswer: ADP ribosylation of adenylate cyclase that stops production of cAMP Mucus helps in protecting against pathogens byAnswer: blocking access and attachment of pathogens to mucosal surfaces Type III secretion systems are used to inject "effector" proteins directly into a host cell. Salmonella uses a type III secretion system to help the pathogen toAnswer: survive within macrophages Which of these cytokines is also known under the name cachectin?Answer: Tumor necrosis factor (TNF) Which is not a major defense mechanism in the stomach?Answer: Dense normal flora The agent responsible for causing mad cow disease is thought to be aAnswer: prion The "A" subunit of diphtheria toxinAnswer: cause ADP ribosylation of a factor involved in protein synthesis Coxsackie virus B3, a subgroup of enteroviruses, commonly causesAnswer: myocarditis Prontosil isAnswer: an effective antibacterial both in animals as well as in in-vitro cultures All infections do not cause fever and all fevers are not due to infections which of the following is an example of non-infections cause of fever?Answer: Rheumatic disease Immunization with which of the following toxoid induces high titer serum antibody, but does not protect from the corresponding disease?Answer: Botulism Which of the following statements is not true regarding Mycobacterium tuberculosis and/or the disease it causes?Answer: Antibodies to the pathogen are protective What is common in catheters and ventilators?Answer: They bypass important defenses of the body An important host defense of human beings is a dense resident microbiota associated withAnswer: vagina Lactoferrin helps to protect against pathogens byAnswer: Sequestering Iron The influenza vaccine is administered each year becauseAnswer: mutations in the viral hemagglutinin may allow the virus to evade the immune response elicited by previous vaccines Which of the following disease is caused by DNA viruses?Answer: Small pox Which of the following is common in the disease caused by Coryne-bacterium diphtheriae and Bacillus anthracis?Answer: The most serious disease symptoms are the direct result of toxin action Fatalities following influenza infection are usually due to theAnswer: bacterial superinfection Which of the following disease is not caused by microbial protein toxin?Answer: Tuberculosis In the human disease cholera, what is it that actually ends up killing the victim?Answer: Dehydration and loss of nutrients Each of the 3 virulence factors of Bacillus anthracis i.e. the capsule, edema toxin and lethal toxin can affect the activity ofAnswer: macrophages Holozoic nutrition is characterized byAnswer: Phagocytosis of solid nutrients and subsequent formation of phagocytic vacuoles Organisms with amoeboid cells that move within a network of mucous tracks using a typical gliding motion belong to which phylum of Protozoa?Answer: Labyinthomorpha Saprozoic nutrition is characterized byAnswer: Pinocytosis of soluble nutrients and subsequent formation of phagocytic vacuoles Which of the following is least likely to have a rigid cell wall?Answer: Protozoan The numbers of nuclear divisions involved in a ciliate undergoing binary fission isAnswer: Lesser than conjugation Which of the following is not a function of cysts for Protozoa?Answer: All of the above Which of the following is not true of protozoa?Answer: Comprise the microbial population known as phytoplankton