Use the Following Information to Answer the Question

question 71

Multiple Choice

Use the following information to answer the question.
Rose-picker's disease is caused by the yeast Sporothrix schenkii (S. schenkii) . The yeast grows on the exteriors of rose-bush thorns. If a human gets pricked by such a thorn, the yeasts can be introduced under the skin. The yeasts then assume a hyphal morphology and grow along the interiors of lymphatic vessels until they reach a lymph node. This often results in the accumulation of pus in the lymph node, which subsequently ulcerates through the skin surface and then drains.
Humans have immune systems in which lymph nodes are important, because many white blood cells (phagocytes and lymphocytes) reside there. Given that a successful infection by S. schenkii damages lymph nodes themselves, which of the following is most probable?

• A) The hyphae secrete antibiotics, which increases the ability of the infected human to tolerate the fungus.
• B) The fungal conversion from yeast to hyphal morphology allows such fast growth that the body's defenses are at least temporarily overwhelmed.
• C) Defensive cells of humans cannot detect foreign cells that are covered with cell walls composed of cellulose.
• D) Given that most fungal pathogens attack plants, human defenses are simply not adapted to seek out and destroy fungi.

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Definitions:

Construct Validity

The degree to which a test or instrument measures the theoretical construct or psychological concept it intends to measure.

Population

The total number of people under consideration.

Sample

A subset of individuals from a larger population, selected for participation in a research study, meant to represent the larger group.

Cohort

A group of individuals sharing a specific characteristic, typically defined by age, who are studied over a period of time.