Question 1

PCR require all of the following except:

Accepted Answer

Answer reason: PCR requires a DNA template, two primers (forward and reverse), a reaction buffer with Mg2+ and dNTPs, and a thermostable DNA polymerase (e.g., Taq). Only one polymerase enzyme is needed in the reaction mix; it repeatedly extends both primers across cycles. Requiring two separate heat-stable polymerases is not a standard component of PCR, making this the exception.
Category reason: This question tests the required components of the polymerase chain reaction, which is a core laboratory method used to detect and study microorganisms and their genetic material, fitting Microbiology.

Question 2

Bacteriophage is ?

Accepted Answer

Answer reason: d- virus that infect bacteria Bacteriophages are viruses that specifically use bacteria as their host cells for replication. They attach to bacterial surfaces, inject their genetic material, and then hijack bacterial machinery to produce new phage particles, often lysing the bacterium. Antibiotics act against bacterial targets and do not “kill” viruses, making the other options incorrect.
Category reason: This question tests foundational knowledge of microorganisms and virus–bacteria interactions, which falls under Microbiology rather than nursing care decisions.

Question 3

All of the following viruses are transmitted by blood except?

Accepted Answer

Answer reason: HIV, HBV, and HCV are classic bloodborne pathogens efficiently transmitted via percutaneous exposure (e.g., needlesticks), transfusion (historically), or contact with infected blood. Herpes simplex viruses are primarily spread through direct contact with infected mucosal surfaces/skin lesions and sexual contact rather than being considered a typical bloodborne virus. While HSV can rarely be detected in blood in disseminated disease (e.g., neonates or severe immunosuppression), this is not the usual route of transmission tested in standard infection-control/virology contexts.
Category reason: This question tests routes of transmission of specific viruses (bloodborne vs non-bloodborne), which is core infectious disease/virology content within Microbiology rather than a nursing intervention or prioritization scenario.

Question 4

All of the following are RNA viruses except?

Accepted Answer

Answer reason: d- poxviridae Poxviridae are large, enveloped viruses with a linear double-stranded DNA genome and replicate in the cytoplasm, making them DNA viruses rather than RNA viruses. Coronaviridae are positive-sense single-stranded RNA viruses. Reoviridae are double-stranded RNA viruses. Picornaviridae are positive-sense single-stranded RNA viruses.
Category reason: This question tests classification of viral families by genome type (RNA vs DNA), which is foundational virology within Microbiology.

Question 5

Penetration of naked virus is by ?

Accepted Answer

Answer reason: Naked (non-enveloped) viruses lack a lipid envelope, so they cannot merge directly with the host cell membrane via fusion. They commonly enter cells through receptor-mediated endocytosis, after which they escape the endosome to deliver the genome for replication. “Translocation” is not the standard primary mechanism for naked virus entry in basic virology, making it less correct than endocytosis.
Category reason: This question tests mechanisms of viral entry (enveloped vs non-enveloped), which is a core concept in microbiology/virology rather than nursing care decision-making.

Question 6

Which is the most effective method for controlling housefly breeding?

Accepted Answer

Answer reason: Houseflies breed primarily in exposed organic waste such as garbage, feces, and decaying matter. Eliminating or properly managing these breeding sites breaks the life cycle and reduces population at the source, making it the most effective and sustainable control method. Chemical approaches like fogging or DDT mainly kill adult flies temporarily, can miss larvae, and carry environmental/toxicity concerns, leading to rebound infestations if waste sources persist.
Category reason: This question tests a foundational public health/microbiology concept about vector breeding sites and environmental control measures rather than bedside nursing prioritization or interventions.

Question 7

The color of gram positive bacteria is?

Accepted Answer

Answer reason: D- Violet Gram-positive bacteria have a thick peptidoglycan cell wall that retains the crystal violet–iodine complex during Gram staining. After the decolorization step, they do not lose the primary stain, so they remain purple/violet. In contrast, gram-negative organisms are decolorized and then take up the counterstain (safranin), appearing pink/red.
Category reason: This question tests knowledge of Gram stain principles and bacterial classification, which is a core topic in Microbiology rather than a nursing intervention or patient-care decision.

Question 8

Selective media for fungi

Accepted Answer

Answer reason: This medium is formulated with an acidic pH and high dextrose content that favors growth of fungi (yeasts and molds) while inhibiting many bacteria. It is the standard selective medium used for isolating fungal organisms in clinical microbiology. In contrast, blood agar and nutrient agar are general-purpose media, and MacConkey agar is selective for gram-negative enteric bacteria.
Category reason: This question tests knowledge of culture media selection for microorganism growth, which is a core concept in Microbiology.

Question 9

Histoplasma is a?

Accepted Answer

Answer reason: A- Systemic mycosis Histoplasma capsulatum is a dimorphic fungus that primarily infects via inhalation and can involve the lungs with potential dissemination through the reticuloendothelial system. Because it can spread beyond superficial or cutaneous layers and cause systemic disease—especially in immunocompromised patients—it is categorized among systemic (deep) mycoses. Subcutaneous mycoses are typically introduced by traumatic implantation, and superficial/cutaneous mycoses are limited to keratinized tissues without systemic spread.
Category reason: This item tests classification of a fungal organism and the type of mycosis it causes, which is a core Microbiology concept rather than a nursing care decision.

Question 10

All are asexual spores produced by mould except?

Accepted Answer

Answer reason: Conidia, sporangiospores, and arthrospores are recognized asexual reproductive spores of many molds. Endospores, in contrast, are classically a bacterial survival structure (e.g., Bacillus, Clostridium) formed under adverse conditions rather than a mold asexual reproductive spore. Therefore, this is the exception among the listed options.
Category reason: This question tests identification of types of microbial spores and their organism associations, which is a core Microbiology concept rather than a nursing care decision.

Question 11

They reproduce only by Asexual reproduction

Accepted Answer

Answer reason: They are classically called “fungi imperfecti” because their sexual stage is not observed, so reproduction is identified only through asexual conidia. In contrast, Ascomycetes and Zygomycetes have defined sexual reproductive structures (ascospores and zygospores, respectively). “Blastomycosis” is a disease entity rather than a fungal reproductive classification group.
Category reason: This question tests fungal classification based on reproductive modes, which is a core concept in Microbiology.

Question 12

The functions of cell wall is all of the following except?

Accepted Answer

Answer reason: Selective permeability and solute transport are functions of the cytoplasmic (plasma) membrane, which contains transport proteins and maintains gradients. The bacterial cell wall primarily provides structural rigidity and shape, prevents osmotic lysis/plasmolysis-related damage by resisting turgor pressure changes, and in Gram-negative bacteria contributes antigenic components (e.g., LPS O antigen) associated with the cell envelope. Therefore, this option does not describe a true cell wall function.
Category reason: This question tests foundational bacterial structure and the distinct roles of cell wall versus cell membrane, which is core content in Microbiology.

Question 13

Which of the following tests confirms HIV diagnosis after a reactive screening test?

Accepted Answer

Answer reason: A reactive screening test (e.g., ELISA or rapid test) requires confirmatory testing with higher specificity to establish the diagnosis. Western blot (historically) and HIV nucleic acid testing (NAT) are used to confirm infection and reduce false-positive results from screening assays. CD4 count assesses immune status and disease progression but does not diagnose HIV. Repeating another screening test (rapid card or ELISA) does not serve as definitive confirmation.
Category reason: This question tests laboratory confirmation of an infectious disease diagnosis (HIV) after screening, which is primarily microbiology/diagnostic testing knowledge rather than a nursing intervention decision.

Question 14

What is the recommended duration for post-exposure prophylaxis (PEP) for HIV?

Accepted Answer

Answer reason: PEP for HIV should be taken as a full 28-day course to maximize suppression of viral replication if infection was acquired. Shorter durations are associated with reduced effectiveness and are not recommended by standard guidelines. While initiation should be as soon as possible (ideally within hours and no later than 72 hours), the total duration remains 28 days once started. Ongoing monitoring for side effects and follow-up HIV testing are part of standard management.
Category reason: This question tests guideline-based biomedical knowledge about HIV post-exposure prophylaxis duration rather than a nursing care prioritization or intervention sequence, fitting best under Microbiology.

Question 15

All are Prokaryotic cells except?

Accepted Answer

Answer reason: a- Fungi Fungi are eukaryotic organisms with a true nucleus and membrane-bound organelles, distinguishing them from prokaryotes. Bacteria are classic prokaryotes lacking a nucleus. Chlamydia are obligate intracellular bacteria but still prokaryotic. Mycoplasma are bacteria without a cell wall and remain prokaryotic.
Category reason: This question tests classification of microorganisms into prokaryotes vs eukaryotes, which is a foundational concept in Microbiology.

Question 16

Vector of kala-azar:

Accepted Answer

Answer reason: Kala-azar (visceral leishmaniasis) is transmitted to humans by the bite of infected female phlebotomine sandflies, which inoculate Leishmania parasites into the skin. This directly matches the required disease vector for kala-azar. Mosquito genera like Anopheles, Aedes, and Culex are vectors for malaria, dengue/yellow fever, and lymphatic filariasis/West Nile respectively, not leishmaniasis. Therefore the sandfly is the single best answer based on the established transmission cycle of Leishmania.

Question 17

Incubation period of polio:

Accepted Answer

Answer reason: Poliovirus has a typical incubation window of about 1–2 weeks, reflecting the time required for initial replication in the oropharynx and gastrointestinal tract before possible viremia and neurologic involvement. This time course is commonly tested as the standard incubation period for poliomyelitis in microbiology/infectious disease fundamentals. The shorter range would be more consistent with infections that cause rapid symptom onset after exposure. The longer ranges overlap with possible extremes reported in some contexts, but they are not the best single “typical” incubation period asked in exam-style questions.

Question 18

The mosquito which transmits yellow fever is?

Accepted Answer

Answer reason: Yellow fever is an arboviral infection transmitted by specific mosquito vectors in endemic regions. The primary urban vector responsible for human-to-human transmission is Aedes aegypti, a day-biting mosquito that breeds in artificial water containers near human habitation. Anopheles is classically linked to malaria transmission, while Culex is more associated with infections like West Nile virus and lymphatic filariasis in many settings. Mansonoides is not the typical vector for yellow fever, making it an unlikely choice.

Question 19

Incubation period of hepatitis A:

Accepted Answer

Answer reason: Hepatitis A virus has a relatively short incubation period compared with other viral hepatitides because it is an acute, self-limited enterically transmitted infection. The typical incubation is about 28 days, commonly ranging from roughly 15 to 50 days, so this option best matches standard epidemiologic ranges. The 2–3 months and 90–120 days ranges align more with hepatitis B (and sometimes hepatitis C), which have longer incubation periods. Knowing the incubation window is clinically important for exposure assessment, contact tracing, and timing of post-exposure prophylaxis.

Question 20

National TB control program follows:

Accepted Answer

Answer reason: Tuberculosis control at the population level relies on standardized case detection, supervised treatment, and outcome monitoring to reduce transmission and prevent drug resistance. The DOTS framework operationalizes these principles through directly observed therapy, assured drug supply, and systematic recording/reporting to ensure adherence and completion. ORS is for dehydration from diarrheal illness and is unrelated to TB program strategy. Vaccination alone (e.g., BCG) does not control adult pulmonary TB transmission, and a generic “antibiotic policy” is not the established national TB control program approach.

Question 21

The disease eradicated globally by 1980:

Accepted Answer

Answer reason: Smallpox is the only human infectious disease that has been officially declared eradicated worldwide. The World Health Organization certified global eradication in 1980 after successful surveillance and ring vaccination strategies. Polio is close to eradication but remains endemic in limited regions, so it cannot be the correct historical milestone. Measles and malaria continue to circulate globally despite available prevention and control measures.

Question 22

Incubation period of measles is –?

Accepted Answer

Answer reason: Measles (rubeola) has a characteristic incubation period from exposure to symptom onset of about 10–14 days, reflecting the time needed for viral replication and dissemination before the prodrome begins. This timeframe is classically tested and aligns with the usual onset of fever, cough, coryza, and conjunctivitis before the rash appears. Much shorter intervals (e.g., 1–2 or 5–7 days) are more typical of other viral illnesses and do not fit measles epidemiology. A 21-day incubation is longer than the usual measles incubation window and is not the standard reference for rubeola.

Question 23

Rabies is caused by?

Accepted Answer

Answer reason: Rabies is an infectious disease caused by rabies virus, a neurotropic Lyssavirus (family Rhabdoviridae) that travels via peripheral nerves to the central nervous system. This directly matches the causative-agent classification being tested, which is viral rather than bacterial, fungal, or protozoal. Clinically, this explains why antibiotics are ineffective and why management relies on post-exposure prophylaxis with vaccine and rabies immune globulin before symptom onset. Once neurologic symptoms begin, the infection is almost uniformly fatal, consistent with viral encephalitis pathophysiology.

Question 24

Malaria is caused by?

Accepted Answer

Answer reason: Malaria is caused by Plasmodium species, which are protozoan parasites transmitted to humans through the bite of infected female Anopheles mosquitoes. The organism first infects hepatocytes and then invades red blood cells, leading to cyclic fevers, hemolysis, and anemia. Viruses and bacteria do not have this intraerythrocytic parasitic lifecycle characteristic of malaria. Helminths are multicellular worms and cause different patterns of disease (e.g., intestinal or tissue helminthiasis) rather than the RBC-stage illness of malaria.

Question 25

Which disease is caused by Bordetella pertussis?

Accepted Answer

Answer reason: Bordetella pertussis is the bacterial pathogen responsible for pertussis, a highly contagious respiratory infection characterized by paroxysmal coughing fits and an inspiratory “whoop,” especially in children. The organism adheres to ciliated respiratory epithelium and produces toxins that impair mucociliary clearance, driving the prolonged cough syndrome. In contrast, tuberculosis is caused by Mycobacterium tuberculosis, diphtheria by Corynebacterium diphtheriae, and tetanus by Clostridium tetani. Therefore the disease linked to Bordetella pertussis is the classic whooping cough presentation.

Question 26

Condidiasis is cause by?

Accepted Answer

Answer reason: The classic presentation includes white, curd-like plaques in the mouth (thrush) that may be associated with antibiotic use, immunosuppression, diabetes, or inhaled corticosteroids. This etiology directly matches fungal organisms rather than bacteria or viruses, which have different clinical patterns and treatments. Management therefore targets fungi with topical or systemic antifungals (e.g., nystatin or fluconazole) and correction of predisposing factors when possible.

Question 27

Diaper rashes is moas commonly caused by.?

Accepted Answer

Answer reason: This organism readily infects macerated, occluded skin in the diaper area and can worsen erythema, crusting, and pustules. In contrast, E. coli is primarily a gut pathogen and is more associated with UTIs and gastroenteritis rather than primary diaper-area skin infection. Diphtheria is a toxin-mediated respiratory/skin illness and streptococci are less commonly cited than this pathogen for typical infected diaper rash patterns in basic nursing science exams.

Question 28

Which is the smallest tape worm infecting man?

Accepted Answer

Answer reason: Hymenlopis nana is a small intestinal cestode that can complete its life cycle in humans and is well known for being much shorter than Taenia species. Taenia saginata and Taenia solium are generally several meters long in the adult form, making them clearly larger. Diphyllobothrium latum is among the longest tapeworms infecting humans, so it is the opposite of the “smallest” choice.

Question 29

Which one of the following is acid bacillus?

Accepted Answer

Answer reason: Species in the genus Mycobacterium are the classic acid-fast organisms due to this cell wall structure. E. coli and Clostridium botulinum are not acid-fast (they stain as typical Gram-negative and Gram-positive organisms, respectively). Lactobacillus species are also not acid-fast and are better known as normal flora/probiotics rather than acid-fast pathogens.

Question 30

Which of the following is not a viral disease?

Accepted Answer

Answer reason: Tetanus is caused by the bacterium Clostridium tetani, which produces a neurotoxin leading to muscle rigidity and spasms. In contrast, polio (poliovirus), smallpox (variola virus), and mumps (mumps virus) are all caused by viruses. This makes the bacterial illness the only option that is not viral.

Question 31

Strawberry spot vagina is seen in?

Accepted Answer

Answer reason: This protozoan STI typically produces a frothy, malodorous yellow-green discharge and vaginal irritation, matching the mechanism behind the mucosal petechiae. Candida more often causes thick curdy white discharge with vulvovaginal erythema but not punctate hemorrhages. Herpes simplex is characterized by painful vesicles/ulcers rather than a strawberry cervix, and CMV does not produce this characteristic finding in routine vaginitis.

Question 32

Koplik spots are seen in?

Accepted Answer

Answer reason: They characteristically occur on the buccal mucosa opposite the molars during the febrile catarrhal (prodromal) phase and precede the maculopapular exanthem by about 1–2 days. This timing makes them a key clinical clue for early recognition and isolation during the most contagious period. In the eruptive phase, the hallmark is the widespread rash rather than the appearance of new oral enanthem, and incubation/convalescence do not feature these diagnostic lesions.

Question 33

Toxic shock syndrome is due to which vaccine?

Accepted Answer

Answer reason: Among the listed vaccine-related associations, the toxoid vaccine connected to toxin biology is the tetanus vaccine because it is derived from inactivated tetanus toxin (toxoid). This makes it the best match to the concept being tested (toxins/toxoid vaccines), whereas mumps, measles, and Salk (polio) vaccines are viral vaccines not centered on bacterial exotoxin mechanisms. Clinically, TSS is typically caused by Staphylococcus aureus or Streptococcus pyogenes, but within these choices the toxoid-based option is the intended answer.

Question 34

Mycology is the study of ?

Accepted Answer

Answer reason: The term comes from the Greek “mykes” meaning fungus, so it directly maps to fungal organisms. Viruses and bacteria are studied under virology and bacteriology, respectively, making them incorrect. Nucleic acids are the focus of molecular biology/biochemistry rather than this organism-based subdiscipline.

Question 35

Negri bodies seen in?

Accepted Answer

Answer reason: This histopathologic hallmark is used to support the diagnosis of rabies in brain tissue. The other listed viruses are associated with different inclusion patterns (e.g., poxviruses show Guarnieri bodies) or different target tissues, not Negri bodies. Therefore the best association is with rabies infection.

Question 36

Chickenpox is caused by?

Accepted Answer

Answer reason: This pathogen classically produces a generalized pruritic vesicular rash in children and can later reactivate as herpes zoster (shingles). Variola virus causes smallpox, a different eradicated orthopoxvirus illness with distinct lesion pattern and severity. Rotavirus primarily causes acute gastroenteritis, not a vesicular exanthem.

Question 37

Most common cause of pyoderma in neonates, is?

Accepted Answer

Answer reason: This organism produces exfoliative toxins that can cause fragile bullae and widespread superficial epidermal splitting in neonates. Candida more typically causes diaper dermatitis or thrush rather than classic pyoderma. E. coli and Chlamydia trachomatis are not typical causes of primary superficial pustular skin infections in neonates.

Question 38

Incubation Period Of Chikungunya is ?

Accepted Answer

Answer reason: Chikungunya virus typically causes acute febrile illness with arthralgia after an incubation of about 2–9 days, which matches this option. Ranges like 3–7 days are narrower and risk excluding common presentations at either end of the typical window. Knowing the incubation period helps with exposure history timing, outbreak investigation, and differentiating it from other arboviral illnesses with different incubation ranges.

Question 39

Mantoux test is done to diagnose?

Accepted Answer

Answer reason: A positive reaction supports TB infection/exposure (latent infection screening) when interpreted with risk factors and induration size cutoffs. It is not a diagnostic test for parasitic infections like malaria or filariasis, which are identified by blood smears/antigen tests. It is also unrelated to typhoid, which is evaluated using culture/serology rather than a tuberculin skin response.

Question 40

Chikungunya is a non-fatal ___ illness?

Accepted Answer

Answer reason: The question tests recognition of the etiologic agent type rather than clinical management. Bacterial causes would suggest antibiotic-responsive pathogens, which does not fit chikungunya. Protozoa/Plasmodium are associated with parasitic diseases such as malaria, not chikungunya.

Question 41

The mosquito that transmit malaria?

Accepted Answer

Answer reason: This option directly matches the established epidemiology of malaria transmission and is the key vector association tested in basic medical science. Culex more commonly transmits infections such as filariasis and some viral encephalitides, and Aedes is classically associated with dengue, Zika, chikungunya, and yellow fever. Therefore, Anopheles is the single best answer.

Question 42

123 The best and safest method of sterilization is?

Accepted Answer

Answer reason: Steam under pressure achieves high temperatures with excellent penetration, making it the standard method for sterilizing heat-stable instruments and dressings. Chemical immersion is typically high-level disinfection and can be limited by contact time, organic load, and inability to ensure complete spore kill. Boiling and flaming are less controlled and less dependable for complete sterilization across materials and loads, making them less safe as a general method.

Question 43

The media used to grow the microorganisms is known as?

Accepted Answer

Answer reason: It can be formulated as liquid (broth), semisolid, or solid (agar) depending on the purpose of cultivation and isolation. A culture plate or culture tube refers to the container/vessel holding the medium, not the growth-supporting substance itself. Therefore the term for the “media used to grow microorganisms” is the medium/media, not the plate or tube.

Question 44

The most common site of hospital-acquired infection is ?

Accepted Answer

Answer reason: Indwelling urinary catheters bypass normal urethral defenses and provide a surface for biofilm formation, enabling ascending bacterial infection over time. This risk rises with longer catheter duration and breaks in aseptic insertion/maintenance. Respiratory and surgical site infections are also important HAIs, but they are generally less common than CAUTI in overall incidence in many inpatient settings.

Question 45

The result of mantoux test are read after ?

Accepted Answer

Answer reason: The induration is optimally measured at 48–72 hours after intradermal PPD placement, with 72 hours commonly used as the standard read time in exams. Reading too early (e.g., 6 or 24 hours) can miss the peak induration and yield a false-negative interpretation. Although 48 hours can be acceptable, the best single choice given is the later end of the recommended window.

Question 46

An example of higher plant parasite is ____ ?

Accepted Answer

Answer reason: Cuscuta (dodder) is a classic obligate parasitic flowering plant that lacks substantial chlorophyll and depends on host vascular tissues. In contrast, Pythium and Phytophthora are oomycete “water molds,” not higher plants, and Agaricus is a mushroom (fungus). Therefore the only option that fits the definition of a higher plant parasite is the angiosperm Cuscuta.

Question 47

Agent used to inhibit the growth of bacteria :-

Accepted Answer

Answer reason: An agent that inhibits bacterial growth prevents multiplication, allowing the host immune system to clear the infection without necessarily causing immediate bacterial death. In contrast, bactericidal agents kill bacteria, while antiseptics and disinfectants describe where the agent is used (living tissue vs inanimate surfaces) rather than specifically indicating growth inhibition. Therefore the best match for “inhibit the growth of bacteria” is the growth-suppressing class.

Question 48

Chikungunya species belongs to which family?

Accepted Answer

Answer reason: Chikungunya virus is an alphavirus, and alphaviruses are members of the Togaviridae family. This distinguishes it from flaviviruses (e.g., dengue, Zika, yellow fever) which fall under Flaviviridae, a common exam distractor. Bunyaviridae and Reoviridae include other RNA viruses but not chikungunya, so they do not match the organism’s taxonomy.

Question 49

Paris Green is used to eliminate the larva of ?

Accepted Answer

Answer reason: Paris green (copper acetoarsenite) is a classic larvicide used particularly against larvae that feed at the water surface, which is characteristic of this genus. In contrast, Mansonoides larvae attach to aquatic plants for oxygen, so surface poisons are less effective for them. Therefore the best match for this agent’s typical use is the surface-feeding mosquito larvae listed.

Question 50

Bacillary dysentery is commonly caused by ?

Accepted Answer

Answer reason: Shigella species are the most common and prototypical cause, transmitted via the fecal–oral route with a very low infectious dose. In contrast, Vibrio cholerae causes profuse watery “rice-water” diarrhea without invasive dysentery, and Klebsiella is more associated with pneumonia/UTIs than dysentery. While some E. coli pathotypes can cause bloody diarrhea, the term “bacillary dysentery” in standard exam usage points most directly to Shigella.

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