Use the Information in the Following Paragraph to Answer the Next

question 56

Multiple Choice

Use the information in the following paragraph to answer the next few questions.
A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan.
-This bacterium derives nutrition by digesting human intestinal contents (in other words, food) . Humans lacking this bacterium have no measurable reproductive advantage or disadvantage relative to humans who harbor this bacterium. Consequently, the bacterium can be properly described as which of the following?
1) symbiont
2) endosymbiont
3) mutualist
4) commensal

• A) 4 only
• B) 1 and 2
• C) 1 and 4
• D) 2 and 3
• E) 2 and 4

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Definitions:

Context Effects

Refers to how the context in which a stimulus occurs can affect the perception of this stimulus.

Perceptual Adaptation

The ability of the body to adjust to an environment by filtering out distractions, allowing for greater focus on particular stimuli.

Perceptual Set

A mental predisposition to perceive one thing and not another, influenced by expectations, emotions, and culture.

Bottom-Up Processing

A type of information processing that begins with sensory input and builds up to the formation of perception in the brain.