A Researcher Is Studying the Fas Receptor (FasR), a Protein

question 16

Multiple Choice

A researcher is studying the Fas receptor (FasR) , a protein widely expressed on cell surfaces.  The signaling cascade of programmed cell death is initiated when FasR binds to its ligand (FasL) , which is expressed on cytotoxic T cells.  In an experiment, cancer cells that escaped elimination by the immune system were found to contain soluble Fas proteins that did not promote apoptosis.  The soluble Fas proteins were shorter and lacked the transmembrane domain.  DNA analysis of these cells revealed no FAS gene mutations.  Which of the following is the most likely explanation for the formation of altered Fas proteins in these cancer cells?

• A)Alternative splicing
• B)Defective polyadenylation
• C)DNA methylation
• D)Polycistronic mRNA
• E)Protein ubiquitination

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Definitions:

Constraints

Factors or conditions that limit or restrict choices, actions, or outcomes within a given context or system.

Large-Scale Patterns

Broad trends or structures in society that affect groups and institutions in significant ways.

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An individual who has one or more children but has never been legally married, which may have specific social, legal, and emotional implications.

Proportion

A part, share, or number considered in comparative relation to a whole; the relationship of one thing to another in terms of quantity, size, or number.