Which Statement Shows an Example of a Commensal Species in One

question 45

Multiple Choice

Which statement shows an example of a commensal species in one host becoming a pathogenic species in another host?

• A) C. difficile flourishes in the large intestine after antibiotic therapy.
• B) New infectious diseases are due to increases in host tropism.
• C) Shigella flexneri preferably infects the tissues of humans and other primates.
• D) E. coli lives harmlessly in the appendix but will be attacked by the immune system if it invades the abdominal cavity.
• E) Up to 30% of pregnant women harbor Group B streptococci in the vagina to no ill effect, but when transmitted to their newborns, a proportion of babies develop serious infection.

---

Definitions:

Reactants

Reactants are substances initially present in a chemical reaction that are consumed during the reaction to form products.

Substrates

In biochemistry, substrates are the specific substances on which an enzyme acts to catalyze a chemical reaction, often converted into products.

Triglycerides

A type of fat found in your blood, used by the body for energy and considered an important measure of heart health.

Monosaccharides

Simple sugars, such as glucose and fructose, which are basic building blocks of carbohydrates and cannot be hydrolyzed to smaller molecules.