Dental Hygienist Practice Test – Microbiology and Immunology

Cytokines are inflammatory mediators that are produced by B-cells and T-cells.

Saliva is predominantly made up of the antibody Immunoglobulin A, also referred to as – secretory antibody. While the other antibodies (i.e Immunoglobulin E, D and G) are also prevalent in saliva, the quantities however, are not as large when compared to that of Immunoglobulin A.

Contact dermatitis is classed as a type IV hypersensitivity reaction involving a cell-mediated response.

Saliva does not increase in volume where there is an increase in inflammation.

A microorganism’s virulence accurately describes its ability to cause disease.

Under a microscope, a disk is not a typical shape of bacterial cells.

A microorganism is an organism which is microscopic, where the individual cells cannot be seen with a naked eye.

A virus is an acellular microorganism that requires a host for replication. A virus can multiply only within the living cells of a host.

From the above listing, the only structure which can transfer genetic material are pili.

Obligate anaerobes can only live and grow in the absence of oxygen. They are suited for growth in those areas where there is limited or nonexistent exposure to oxygen.

Glycosaminoglycans (also known as mucopolysaccharides) are long chains of sugar molecules in the body and are not linked to bacterial virulence.

Organisms classed as mesophiles are most likely to be human pathogens. Mesophiles grow best at human body temperature.

Microorganisms that are classed as beta-hemolytic have the capability to destroy or lyse red blood cells.

Septic shock can develop in individuals where large amounts of endotoxins (or lipopolysaccharides) have entered the bloodstream. Endotoxins are produced by some species of gram-negative bacteria when the cells lyse, divide or both.

It is necessary to differentiate symptoms from signs.  Symptoms are characteristics of a disease which cannot be measured or observed. Whereas ‘signs’ of a disease display characteristics which can either be measured, observed or both.  Sore throat cannot be measured or observed, but rather is a condition which can only be felt by the individual. All the other remaining options (i.e. Fever, Vomiting, and high blood pressure) can all be observed and measured.

Droplet transmission is referred to as the transmission of a microorganism in the air over distances less than 1 meter.

The mucous membranes of the respiratory tract are the most common platform of entry for pathogenic microorganisms.

A fomite is an inanimate object used in secondary or indirect contact transmission, spreading a pathogen from one reservoir to the next susceptible host. A hypodermic needle is a fomite.

T-helper cells result in the production of cytokines, which are chemical messengers that activate and boost other components of the immune system.

Adaptive immune response is a specific immune response that specifically targets the pathogen that stimulated it. Hence, ‘Nonspecific’ is incorrect.