Host-Parasite Interaction Review

Organisms that participate in a biologic relationship where both benefit from one another are called:

• parasites.

• symbionts.

• hosts.

• flora.

Parasitism is a:

• biologic relationship between two or more organisms in which both benefit from one another.

• biologic relationship between only two organisms in which there are no beneficial or harmful effects to the host.
  

• biologic relationship in which one species gains benefits at the expense of the host.

• synonym for mutualism

What is the name of the bacterial state that occurs when a host harbors a disease-causing organism, but does not show signs of disease?

• Carrier

• Transient

• Resident

• Indigenous

Healthy people are colonized by many different bacteria in many different sites. These bacteria are referred to as _____ flora.

• transient

• carrier

• maintenance

• indigenous

Diabetics may sometimes be infected with their own resident flora. This type of infection is called:

• an opportunistic infection.

• a carrier state.

• symbiosis.

• a parasitic infection.

Mechanisms used by the skin to prevent infection and protect the underlying tissue from invasion by potential pathogens include all the following EXCEPT:

• desquamation (peeling) of the epithelium.

• excretion of lysozyme by sweat glands.

• antibiotics that inhibit many microorganisms.

• mechanical separation of microorganisms from the tissues.

A laboratory professional is testing a new antimicrobial soap. The tech washes her forearm then does a culture of the skin. Which organisms should she most likely expect to find growing in the culture?

• Diphtheroids and Bacillus spp.

• Staphylococcus epidermidis and Propionibacterium

• S. aureus and Propionibacterium

• Diphtheroids and Propionibacterium

• None of these organisms should be found.

What mechanism allows strict anaerobes to grow in the cervices and areas between the teeth when plaque is present?

• A low oxidation-reduction potential occurs at the tooth surface under the plaque.

• The bacteria secrete sugar to nourish the strict anaerobes.

• The normal flora secrete antibiotics to kill all the other bacteria and allow the strict anaerobes to thrive.

• The plaque-causing bacteria secrete an alkaline fluid and change the pH around the tooth.

Tags

NGSS.HS-LS2-3

All the following are potentially pathogenic organisms found in the nasopharynx of healthy individuals except:

• Haemophilus influenzae.

• Streptococcus pneumoniae.

• Streptococcus mutans.

• Neisseria meningitidis.

The stomach can be considered a first line of defense against microbial infections because:

• most microorganisms are susceptible to the antibiotics and alkaline pH present in the stomach.

• most microorganisms are killed by the liver enzymes that are emptied into the stomach during a meal.

• the stomach produces proteases, which attacks the lipopolysaccharide cell wall of the organisms.

• most microorganisms are susceptible to the acid pH of the stomach.