NEET (Medical) Biology — Microbiology Mock Test

All Biology — Microbiology sets

Sample Biology — Microbiology questions

1. 1. Sabin Feldman dye test is used for diagnosis of which of the following condition:

   • (A) Yellow fever
   • (B) Sarcoidosis
   • (C) Botulism
   • (D) Toxoplasmosis
   Show answer

   (D) Toxoplasmosis. Ans. b. ToxoplasmosisRef: Diagnosis & Treatment of Uveitis by C Stephen Foster; Page No- 555 & Oskis Pediatrics: Principles & Practice edited by Julia A. McMillan; Page No-1356The Sabin Feldman dye test is the gold standard to which all serologic tests performed to detect anti-T. gondii antibodies are compared.It is a neutralization test in which the patients serum is incubated with complement and live Toxoplasma organisms, and a dye is employed to quantify the bound antibody.It allows early detection of the infection and has high sensitivity and specificity in both acute and chronic phases.This test makes use of the uptake by Toxoplasma tachyzoites of the dye methylene blue (in which organisms appear swollen and blue). The tachyzoites membranes lyse in the presence of complement and specific antibody (Primarily IgG) resulting thin, unstained-appearing organisms.This test has been used extensively as a screening test for toxoplasma infection; it has been recommended as the test of choice for antenatal maternal screening, but it is available only in reference laboratories.However, it is no longer used because it requires maintenance of live virulent parasites in the laboratory, and equally good, safer methods have been developed. Currently, the Sabin Feldman dye test is restricted to research centers as a method to standardize new tests.

2. 2. HCV is associated with -a) Anti LKM-1 antibody b) Sclerodermac) Cryoglobulinemiad) Polyarteritis nodosa

   • (A) ac
   • (B) ad
   • (C) a
   • (D) b
   Show answer

   (A) ac. Several studies have observed a relationship between hepatitis C virus infection and anti-liver/kidney microsome-1 (anti-LKM-1) positive chronic hepatitis. It has been suggested that hepatitis C may induce an autoimmune phenomenon that leads to the development of a specific type (type II anti-LKM-1 positive) autoimmune chronic hepatitis- Journal- J Viral Hepat. 1995; 2(4):175-9.

3. 3. In a bacterial growth curve, the period in which maximum cell size is obtained is_____

   • (A) Beginning of Lag phase
   • (B) Log phase
   • (C) Beginning of stationary phase
   • (D) End of lag phase
   Show answer

   (D) End of lag phase. Bacterial Growth Curve: The bacterial growth curve shows the following four distinct phases - 1) Lag phase: Bacteria adapt to their new environment. Enzymes and intermediates are formed and accumulate until they are present in concentrations that permit growth to resume. Bacterial cell size is maximum in end of the lag phase. It is Preparatory phase Accumulation of enzymes and metabolites 2. Log or Exponential Phase: 3. Stationary phase: The bacterial growth almost stops completely due to lack of essential nutrients, lack of water oxygen, change in pH of the medium, etc. and accumulation of their own toxic metabolic wastes. Death rate of bacteria equals the rate of replication of bacteria. Endospores sta forming during this stage. Many bacteria sta producing exotoxins. Bacteria become Gram variable and show irregular staining. 4. Decline phase: During this phase, the bacterial population declines due to death of cells. The decline phase stas due to - Accumulation of toxic products and autolytic enzymes and Exhaustion of nutrients. Involution forms are common in this stage.

NEET (Medical) Biology — Microbiology — FAQs

Other NEET (Medical) subjects