How Are Natural Killer (NK) Cells Different from Cytotoxic T

question 27

Multiple Choice

How are natural killer (NK) cells different from cytotoxic T (TC) cells?

• A) NK cells induce apoptosis in their target cells, whereas TC cells are professional phagocytes.
• B) NK cells kill virus-infected cells, whereas TC cells kill cancerous cells.
• C) NK cells kill cells with a high level of class I MHC protein expression, whereas killing by TC cells requires low expression levels.
• D) NK cells respond quickly to a virus infection, whereas the activation of TC cells to become cytotoxic is a slow process.
• E) NK cells are normally abundant in the tissue even before infection, whereas TC cells are mostly in the bloodstream.

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Definitions:

Ethology

The scientific study of animal behavior, often with a focus on behavior under natural conditions, and the understanding of behavior from an evolutionary perspective.

Biologically-Oriented

A perspective or approach that focuses on the biological or genetic factors in the study of organisms or behaviors.

Development

The process of growth or progression through a series of progressive changes, typically from a simpler to a more complex or better state.

Mesosystem

The interlocking settings that influence the child, such as the interaction of the school and the larger community when children are taken on field trips.