BioskillPro

Which WBC is characterized by a multilobed nucleus and neutral staining granules?

• Eosinophil

• Monocyte

• Neutrophil

• Basophil

The WIDAL test is based on which immunological principle?

• Precipitation

• Neutralization

• Agglutination

• Complement fixation

MacConkey agar is selective for which type of bacteria?

• Gram-positive

• Gram-negative

• Acid-fast

• Anaerobic

In immunoelectrophoresis, what can cause the appearance of an arc that is broader and less intense than others?

• Antigen excess

• Antibody excess

• Low-affinity antigen-antibody interaction

• High-affinity antigen-antibody interaction

What does the presence of a black precipitate in the TSI slant indicate?

• Lactose fermentation

• Hydrogen sulfide production

• No fermentation

• Gas production

Why might two amino acids with similar structures have different Rf values in TLC?

• Different affinities for the mobile phase

• Different molecular weights

• Different polarities

• Both A and C

Which of the following is a selective feature of TCBS agar that supports the growth of Vibrio species?

• High bile salt concentration

• Low pH

• Presence of thiosulfate and citrate

• High NaCl concentration

What does the presence of multiple precipitin arcs at different positions in an immunoelectrophoresis assay indicate about the antibody specificity?

• It is polyclonal, recognizing multiple epitope

• It is monoclonal, recognizing a single epitop

• It has low affinity for the antigen.

• It indicates non-specific binding.

What is the implication of a WIDAL test showing a high titer for O antigen but not for H antigen?

• Early acute typhoid fever

• • Past typhoid infection.

• Recent vaccination

• Chronic typhoid carrier state