Which of the Following Statements About Ig Isotype Switching Is

question 7

Multiple Choice

Which of the following statements about Ig isotype switching is NOT true?

• A)Interleukin-4 promotes switching to the IgE isotype by increasing germline transcription of the CϬ exon.
• B)Isotype switching involves recombination of a V(D)J complex with downstream C region genes and the deletion of intervening DNA including other C region genes.
• C)Activation-induced deaminase (AID) is required for switch recombination.
• D)The enzymes that mediate isotype switching recognize conserved heptamer and nonamer DNA sequences adjacent to the constant region exons.
• E)The same recombined V(D)J gene complex is used to encode the antigen-binding region of the antibodies produced by a B cell before and after isotype switching.

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Definitions:

Impedance

A measure of the opposition that a circuit presents to the passage of a current when a voltage is applied, incorporating both resistance and reactance.

Parallel Circuit

An electrical circuit configuration where components are connected across common points or junctions, leading to the same voltage across all components but different currents through each.

Resonance

A phenomenon in which a system's natural frequency of oscillation is excited by another oscillating system, leading to a significant increase in amplitude at certain frequencies.

Power Factor

A ratio indicating the efficiency with which an electrical system converts electrical power into useful work output, particularly in AC circuits.