All Free Veterinary Science MCQs with Answers

• A. Placental blood transfer
• B. Colostrum consumption
• C. Amniotic fluid ingestion
• D. Milk produced after weaning

Explanation: Ruminants have a syndesmochorial placenta that allows little or no prenatal transfer of immunoglobulins.

• A. MHC II with CD8-positive T cells
• B. MHC I with CD4-positive T cells
• C. MHC I with CD8-positive T cells
• D. MHC II with B lymphocytes

Explanation: MHC I molecules present intracellular antigens to CD8-positive cytotoxic T cells.

• A. Canine distemper virus
• B. Bovine viral diarrhoea virus
• C. Feline calicivirus
• D. Rabies virus

Explanation: Negri bodies are eosinophilic cytoplasmic inclusions found particularly in neurons infected with rabies virus.

• A. Type I hypersensitivity
• B. Type II hypersensitivity
• C. Type III hypersensitivity
• D. Type IV hypersensitivity

Explanation: Type I hypersensitivity is an immediate allergic reaction involving IgE bound to mast cells, followed by mediator release after…

• A. It produces no cellular immunity
• B. It often induces strong humoral and cellular immunity
• C. It cannot replicate in the vaccinated host
• D. It always remains safe in pregnant animals

Explanation: Live attenuated vaccines usually replicate to a limited extent and stimulate both antibody-mediated and cellular immune responses.

• A. A thin peptidoglycan layer
• B. An outer lipopolysaccharide membrane
• C. A thick peptidoglycan layer
• D. A capsule rich in polysaccharides

Explanation: Gram-positive bacteria have a thick peptidoglycan layer that traps the crystal violet iodine complex during decolorization.

• A. Lag phase
• B. Death phase
• C. Stationary phase
• D. Logarithmic phase

Explanation: The logarithmic, or exponential, phase is marked by rapid and regular cell division.

• A. Tetanospasmin
• B. Botulinum toxin
• C. Staphylococcal enterotoxin
• D. Cholera toxin

Explanation: Tetanospasmin is the neurotoxin produced by Clostridium tetani and causes spastic paralysis by blocking inhibitory neurotransmission.

• A. Respiratory mucosa
• B. Digestive or genital mucosa
• C. Intact skin surface
• D. Central nervous system

Explanation: Brucella abortus commonly enters through the digestive or genital mucosa, especially after contact with contaminated fetal membranes…

• A. A nonsegmented RNA genome
• B. A double-stranded DNA genome
• C. A segmented RNA genome
• D. A lipid-free protein capsid

Explanation: Influenza viruses possess a segmented RNA genome, so two strains infecting the same cell can exchange genome segments.

• A. Protozoal multiplication in erythrocytes
• B. Viral replication in neurons
• C. Bacterial growth in muscle tissue
• D. Keratin invasion by fungal hyphae

Explanation: Dermatophytes grow in keratinized tissues such as the skin, hair, and nails, producing superficial circular lesions.

• A. Antigen-antibody immune complexes
• B. IgE-coated mast cells
• C. Sensitized T lymphocytes
• D. Cytotoxic natural killer cells

Explanation: Type III hypersensitivity results from circulating antigen-antibody complexes depositing in tissues and activating inflammation.

• A. IgA
• B. IgM
• C. IgG
• D. IgE

Explanation: IgM is generally the first immunoglobulin released during a primary immune response.

• A. Viral shape by microscopy
• B. Bacterial motility in culture
• C. Antibody in the serum sample
• D. Antibiotic concentration in tissues

Explanation: An indirect ELISA commonly detects antibodies in a serum sample by using an enzyme-labelled secondary antibody.

• A. Erythropoietin
• B. Histamine
• C. Bradykinin
• D. Interferon

Explanation: Interferons, especially type I interferons, stimulate antiviral mechanisms in infected and neighboring cells and help activate natural…

• A. Transduction
• B. Conjugation
• C. Transformation
• D. Transposition

Explanation: Transduction occurs when a bacteriophage carries bacterial DNA from one cell to another.

• A. Corynebacterium pseudotuberculosis
• B. Pasteurella multocida
• C. Erysipelothrix rhusiopathiae
• D. Listeria monocytogenes

Explanation: Pasteurella multocida may show bipolar staining, giving a safety-pin appearance with suitable stains.

• A. Neurotoxin
• B. Enterotoxin B
• C. Phospholipase C
• D. Botulinum toxin

Explanation: Clostridium perfringens type A produces alpha toxin, which is phospholipase C and damages cell membranes.

• A. Conjugation
• B. Transduction
• C. Translocation
• D. Transformation

Explanation: Transformation is the acquisition of free DNA from the environment by a competent bacterial cell.

• A. Bursa of Fabricius
• B. Spleen
• C. Thymus
• D. Cecal tonsil

Explanation: The bursa of Fabricius is the major site of B-cell development in birds.