A Physician Notices That Several Patients Are Infected with Clostridium

question 4

Multiple Choice

A physician notices that several patients are infected with Clostridium difficile, but only a few of the patients are symptomatic for disease. The reason for this discrepancy is

• A) only those strains of the organism carrying the extrachromosomal DNA coding for the toxin gene will produce toxin and cause the individuals to be symptomatic.
• B) only those strains of the organism carrying DNA coding for the toxin within its main DNA molecule will produce toxin and cause the individuals to be symptomatic.
• C) the exotoxin produced contains only the nontoxic portion.
• D) the exotoxin must be produced in conjunction with extracellular enzymes to cause problems.

---

Definitions:

Emerging Adulthood

A phase of life between adolescence and full-fledged adulthood that encompasses late teens through the twenties, marked by exploration of identity.

Adolescence

A developmental stage between childhood and adulthood characterized by significant physical, psychological, and social changes, including puberty and identity exploration.

Empty-nest Syndrome

A feeling of grief and loneliness parents may feel when their children leave home for the first time, such as to live on their own or attend college.

Concrete Operational Stage

A phase in Piaget's theory of cognitive development (ages 7-12), where children gain a better understanding of mental operations and can think logically about concrete events.