401. To influence microbes, mutation must be:
A. Inheritable
B. Permanent
C. Beneficial
D. Both ‘A’ & ‘B’ ✅
A. Inheritable
B. Permanent
C. Beneficial
D. Both ‘A’ & ‘B’ ✅
402. Which of following features is NOT true for plasmid?
A. It is a circular piece of DNA.
B. It is required for normal cell function ✅
C. It is found in bacteria.
D. It can be transferred from cell to cell.
A. It is a circular piece of DNA.
B. It is required for normal cell function ✅
C. It is found in bacteria.
D. It can be transferred from cell to cell.
403. What is the smallest unit of heredity?
A. Chromosome
B. Gene ✅
C. Codon
D. Nucleotide
A. Chromosome
B. Gene ✅
C. Codon
D. Nucleotide
404. _____ is ‘general feeling of illness and discomfort’.
A. Cystitis
B. Malaise ✅
C. Arthritis
D. Lymphopenia
A. Cystitis
B. Malaise ✅
C. Arthritis
D. Lymphopenia
405. Point mutation involves:
A. Deletion
B. Insertion
C. Duplication
D. Change in single base pair ✅
A. Deletion
B. Insertion
C. Duplication
D. Change in single base pair ✅
406. ________ does not have any normal microbiota.
A. Upper respiratory tract
B. Ovary ✅
C. External genitalia
D. Skin
A. Upper respiratory tract
B. Ovary ✅
C. External genitalia
D. Skin
407. Salt and sugar preserve food because they:
A. Make them acid
B. Produce a hypotonic environment
C. Produce a hypertonic environment ✅
D. Deplete nutrients
A. Make them acid
B. Produce a hypotonic environment
C. Produce a hypertonic environment ✅
D. Deplete nutrients
408. An infant with neonatal meningitis has a positive CAMP test, the causative agent is:
A. Staphylococcus aureus
B. E. coli
C. Streptococcus agalactiae ✅
D. Haemophilus
A. Staphylococcus aureus
B. E. coli
C. Streptococcus agalactiae ✅
D. Haemophilus
409. Two hallmarks of the adaptive immune system are:
A. Immediate and Broad
B. Innate and Short
C. Specificity and Memory ✅
D. Non-specific and Fast
A. Immediate and Broad
B. Innate and Short
C. Specificity and Memory ✅
D. Non-specific and Fast
410. Which of the following mutations would likely cause the greatest impact?
A. Silent
B. Missense
C. Nonsense ✅
D. Inversion
A. Silent
B. Missense
C. Nonsense ✅
D. Inversion
411. X-rays cause mutation by:
A. Deletion
B. Transition
C. Transversion
D. Base substitution ✅
A. Deletion
B. Transition
C. Transversion
D. Base substitution ✅
412. All Gram-Negative bacilli have _______?
A. Capsule
B. Exotoxin
C. Coagulase
D. Endotoxin ✅
A. Capsule
B. Exotoxin
C. Coagulase
D. Endotoxin ✅
413. _______ enzyme of HIV-1 converts RNA to DNA.
A. Protease
B. Integrase
C. Reverse transcriptase ✅
D. RNase
A. Protease
B. Integrase
C. Reverse transcriptase ✅
D. RNase
414. Leptospira is transmitted (animal to human) by?
A. Animal scratch
B. Contact with urine from infected animal ✅
C. Animal bite
D. Arthropod vector
A. Animal scratch
B. Contact with urine from infected animal ✅
C. Animal bite
D. Arthropod vector
415. Which causes food INTOXICATION?
A. Clostridium tetani
B. Staphylococcus aureus ✅
C. Streptococcus pyogenes
D. Salmonella
A. Clostridium tetani
B. Staphylococcus aureus ✅
C. Streptococcus pyogenes
D. Salmonella
416. Crimean-Congo hemorrhagic fever (CCHF) is transmitted by a vector i.e. __________.
A. Mosquitoes
B. Ticks ✅
C. Fleas
D. Sand-fly
A. Mosquitoes
B. Ticks ✅
C. Fleas
D. Sand-fly
417. All are correct for Giardia lamblia EXCEPT?
A. It is transmitted by the fecal oral route.
B. It has only trophozoite stage ✅
C. It can be diagnosed by the string test
D. It can divide by binary fission.
A. It is transmitted by the fecal oral route.
B. It has only trophozoite stage ✅
C. It can be diagnosed by the string test
D. It can divide by binary fission.
418. All are correct for anthrax bacilli EXCEPT?
A. They are spore forming.
B. They are non-fastidious.
C. They produce endotoxin ✅
D. They have polypeptide capsule.
A. They are spore forming.
B. They are non-fastidious.
C. They produce endotoxin ✅
D. They have polypeptide capsule.
419. Culture media are commonly sterilized by:
A. Autoclaving ✅
B. β-radiation
C. Hot air oven
D. Tyndallization
A. Autoclaving ✅
B. β-radiation
C. Hot air oven
D. Tyndallization
420. All of the following are functions of IgG EXCEPT:
A. Opsonize bacteria
B. Be secreted into mucus ✅
C. Activate complement
D. Neutralize toxins
A. Opsonize bacteria
B. Be secreted into mucus ✅
C. Activate complement
D. Neutralize toxins
421. All of the following are viral infections EXCEPT:
A. Chickenpox
B. Measles
C. Malaria ✅
D. Mumps
A. Chickenpox
B. Measles
C. Malaria ✅
D. Mumps
422. DNA is copied during a process called:
A. Transformation
B. Replication ✅
C. Translation
D. Transcription
A. Transformation
B. Replication ✅
C. Translation
D. Transcription
423. An example/examples of a nonspecific chemical barrier to infection is/are:
A. Unbroken skin
B. Cilia in respiratory tract
C. Lysozyme in saliva
D. All of these ✅
A. Unbroken skin
B. Cilia in respiratory tract
C. Lysozyme in saliva
D. All of these ✅
424. _____is a nonspecific host defense related to trachea:
A. Lacrimation
B. Ciliary Lining ✅
C. Desquamation
D. Lactic acid
A. Lacrimation
B. Ciliary Lining ✅
C. Desquamation
D. Lactic acid
425. Autoclaving is done in:
A. Dry air at 121°C and 15 lbs pressure
B. Steam at 100°C for 30 minutes
C. Steam at 121°C for 30 minutes ✅
D. Dry air at 160°C for 30 minutes
A. Dry air at 121°C and 15 lbs pressure
B. Steam at 100°C for 30 minutes
C. Steam at 121°C for 30 minutes ✅
D. Dry air at 160°C for 30 minutes
426. Culture media are sterilized by:
A. Autoclaving ✅
B. β-radiation
C. Hot air oven
D. Tyndallization
A. Autoclaving ✅
B. β-radiation
C. Hot air oven
D. Tyndallization
427. pH of Sabouraud dextrose agar is adjusted to:
A. 1-2
B. 4-6 ✅
C. 6-8
D. 8-10
A. 1-2
B. 4-6 ✅
C. 6-8
D. 8-10
428. Monocytes are ______________ leukocytes that develop into ___________:
A. Granular, phagocytes
B. Agranular, mast cells
C. Agranular, macrophages ✅
D. Granular, T cells
A. Granular, phagocytes
B. Agranular, mast cells
C. Agranular, macrophages ✅
D. Granular, T cells
429. Which of the following is a sterilizing agent?
A. Dry heat ✅
B. Ether
C. Ethanol
D. Chlorohexidine
A. Dry heat ✅
B. Ether
C. Ethanol
D. Chlorohexidine
430. _____________ is included in GALT:
A. Thymus
B. Tonsils
C. Peyer’s patches ✅
D. Breast lymph nodes
A. Thymus
B. Tonsils
C. Peyer’s patches ✅
D. Breast lymph nodes
431. _________ is the MOST resistant to antiseptics?
A. Spore ✅
B. Prion
C. Cyst
D. Fungus
A. Spore ✅
B. Prion
C. Cyst
D. Fungus
432. Which of the following inflammatory signs specifies pain?
A. Tumor
B. Calor
C. Dolor ✅
D. Rubor
A. Tumor
B. Calor
C. Dolor ✅
D. Rubor
433. An example of an exogenous pyrogen is ________:
A. Interleukin-1
B. Complement
C. Interferon
D. Endotoxin ✅
A. Interleukin-1
B. Complement
C. Interferon
D. Endotoxin ✅
434. ______________ is an example of an inflammatory mediator that stimulates vasodilation:
A. Collagen
B. Histamine ✅
C. Complement C5a
D. Interferon
A. Collagen
B. Histamine ✅
C. Complement C5a
D. Interferon
435. ______ is an example of an inflammatory mediator that stimulates chemotaxis:
A. Tumor necrosis factor
B. Serotonin
C. Granulocyte-colony stimulating factor
D. Interleukin-2 ✅
A. Tumor necrosis factor
B. Serotonin
C. Granulocyte-colony stimulating factor
D. Interleukin-2 ✅
436. _____interferon, produced by T lymphocytes, activates cells called _____and is involved in destroying viruses:
A. Beta, lymphocytes
B. Gamma, fibroblasts ✅
C. Alpha, natural killer cells
D. Beta, fibroblasts
A. Beta, lymphocytes
B. Gamma, fibroblasts ✅
C. Alpha, natural killer cells
D. Beta, fibroblasts
437. Which of the following is the end-product of the complement system?
A. Properdin
B. Cascade reaction
C. Membrane attack complex ✅
D. Complement factor C9
A. Properdin
B. Cascade reaction
C. Membrane attack complex ✅
D. Complement factor C9
438. TNF is NOT involved in which process?
A. Chemotaxis of phagocytes ✅
B. Fever
C. The inflammatory response
D. The classic complement pathway
A. Chemotaxis of phagocytes ✅
B. Fever
C. The inflammatory response
D. The classic complement pathway
439. Which of the following statements is true?
A. Solid media are enrichment media
B. Nutrient broth is basal media ✅
C. Agar adds nutrients to media
D. Chocolate agar is selective media
A. Solid media are enrichment media
B. Nutrient broth is basal media ✅
C. Agar adds nutrients to media
D. Chocolate agar is selective media
440. Choose the correct order of decreasing resistance to sterilization:
A. Prions, bacterial spores, bacteria ✅
B. Bacterial spores, bacteria, prions
C. Bacteria, prions, bacterial spores
D. Prions, bacteria, bacterial spores
A. Prions, bacterial spores, bacteria ✅
B. Bacterial spores, bacteria, prions
C. Bacteria, prions, bacterial spores
D. Prions, bacteria, bacterial spores
441. A signaling molecule from microbes recognized by phagocytes is:
A. Pyrogen
B. Pathogen Associated Molecular Patterns ✅
C. Complement
D. Lectin
A. Pyrogen
B. Pathogen Associated Molecular Patterns ✅
C. Complement
D. Lectin
442. Which of the following microorganisms is used as an indicator in autoclave sterilization?
A. Clostridium tetani
B. Bacillus stereothermophilus ✅
C. Bacillus anthracis
D. Clostridium botulinum
A. Clostridium tetani
B. Bacillus stereothermophilus ✅
C. Bacillus anthracis
D. Clostridium botulinum
443. MacConkey agar is an example of:
A. Enrichment medium
B. Selective medium
C. Differential medium
D. Both “B” and “C” ✅
A. Enrichment medium
B. Selective medium
C. Differential medium
D. Both “B” and “C” ✅
444. Virus-mediated transfer of DNA from one cell to another is known as:
A. Transfection
B. Transduction ✅
C. Transformation
D. Transcription
A. Transfection
B. Transduction ✅
C. Transformation
D. Transcription
445. Bacteria may acquire characteristics by all of the following EXCEPT:
A. Taking up soluble DNA from the environment
B. Through bacteriophages
C. Through conjugation
D. Incorporating part of host DNA ✅
A. Taking up soluble DNA from the environment
B. Through bacteriophages
C. Through conjugation
D. Incorporating part of host DNA ✅
446. The __________ is responsible for antibiotic resistance in bacteria due to slime production:
A. Co-aggregation
B. Biofilm formation ✅
C. Mutation evolving in altered target site for antibiotic
D. Mutation evolving a target bypass mechanism
A. Co-aggregation
B. Biofilm formation ✅
C. Mutation evolving in altered target site for antibiotic
D. Mutation evolving a target bypass mechanism
447. Which statement is correct regarding functions of plasmid?
A. Involved in multidrug resistance transfer ✅
B. Imparts capsule formation
C. Imparts pilli formation
D. All of these
A. Involved in multidrug resistance transfer ✅
B. Imparts capsule formation
C. Imparts pilli formation
D. All of these
448. Phage typing is useful as an epidemiological tool in all, EXCEPT:
A. Salmonella
B. Staphylococcus aureus
C. Vibrio cholerae
D. Shigella dysenteriae ✅
A. Salmonella
B. Staphylococcus aureus
C. Vibrio cholerae
D. Shigella dysenteriae ✅
449. The segment of DNA between chromosomal and extrachromosomal DNA molecules within cells is:
A. Cosmids
B. Plasmids
C. Transposons
D. Episomes ✅
A. Cosmids
B. Plasmids
C. Transposons
D. Episomes ✅
450. True about bacteriophage is:
A. Can transmit toxin to bacteria ✅
B. Bacteria which transmits DNA to another bacteria
C. Causes transformation of bacteria
D. Is a virus which invades bacteria
A. Can transmit toxin to bacteria ✅
B. Bacteria which transmits DNA to another bacteria
C. Causes transformation of bacteria
D. Is a virus which invades bacteria
