MDS PREP
Which of the following is NOT a method used to produce a recombinant hepatitis B vaccine?
1) Cloning the HBsAg gene in E. coli
2) Cloning the HBsAg gene in yeasts Saccharomyces cerevisae
3) Extracting and purifying HBsAg particles from infected human plasma
4) Using baculovirus vectors to produce HBsAg in insect cells
General Microbiology Answer: 1
While recombinant hepatitis B vaccines are produced using various methods, cloning the HBsAg gene in E. coli is not one of them. Instead, the gene is typically cloned in yeast or insect cells to produce the surface antigen for the vaccine.
The first person becoming sick in an epidemic is called -
1. Primary case
2. Source of infection
3. Reservoir of infection
4. Index case
Microbiology
Answer: 4
The first recognized case in an epidemic outbreak is termed as the index case. Although both the index case and primary case appear to be the same yet they differ slightly. The term primary case refers to the person who first brings a disease into a group of people.
Which of the following is considered as a disadvantage in the application of dry heat as a sterilizing agent?
1. Requires excessive time
2. Does not destroy hepatitis viruses
3. Dulls instrument cutting edges
4. All of the above
Microbiology
Answer: 1
Which of the following is NOT a characteristic of anthracoid bacilli?
1) Generally motile
2) Non-capsulated
3) Grow in long chains
4) Pathogenic to laboratory animals
Anthracoid bacilli are generally non-motile and non-capsulated, and they do not grow in long chains.
What does the Vi antigen of S. typhi confer upon the bacterium?
1) Resistance to antibiotics
2) Increased invasiveness
3) Resistance to phagocytosis
4) Resistance to acidic environment
General Microbiology Answer: 3the Vi antigen of S. typhi confers upon the bacterium Resistance to phagocytosis. The Vi antigen is a polysaccharide capsule that protects the bacteria from being engulfed and destroyed by phagocytic white blood cells, contributing to its virulence.
What type of genome do Hepatitis B viruses have?
1) ssRNA
2) dsDNA
3) ssDNA
4) dsRNA
General Microbiology Answer: 2Hepatitis B viruses possess a double-stranded DNA (dsDNA) genome, which is unique among the hepatitis viruses. This dsDNA is partially double-stranded and circular, playing a crucial role in the virus life cycle and replication.
What is the first X-linked immunodeficiency disease to have been recognized?
1) X-linked agammaglobulinemia
2) Severe combined immunodeficiency (SCID)
3) X-linked chronic granulomatous disease (CGD)
4) Wiskott-Aldrich syndrome
General Microbiology Answer: 1the first X-linked immunodeficiency disease to be recognized is X-linked agammaglobulinemia. It is a primary immunodeficiency disorder caused by a mutation in the X-chromosome-linked gene responsible for the production of antibodies (specifically, immunoglobulins), leading to a deficiency of B cells and impaired humoral immunity.
Which of the following acids is intermediate in the biosynthesis the cell wall?
1. Alanyl diaminopimelic
2. L-glutamic
3 Uridylic
4. N-acetyl muramic
Microbiology
Answer: 4
N-acetyl muramic is intermediate in the biosynthesis the cell wall