Which of the Following Statements Are True of a T

question 35

Multiple Choice

Which of the following statements are true of a T cell that expresses two α chains (and thus two different T-cell receptors) as a result of ineffective allelic exclusion of the α chain during rearrangement? (Select all that apply.)

• A)Engaging either of the T-cell receptors on MHC molecules of the thymic epithelium will result in positive selection.
• B)One of the T-cell receptors will be functional while the other will most probably be non-functional.
• C)If either T-cell receptor binds strongly to self-peptides presented by self-MHC molecules,the thymocyte will be negatively selected.
• D)One of the T-cell receptors may be autoreactive but escape negative selection because its peptide antigen is present in tissues other than the thymus.
• E)Subsequent gene rearrangements may give rise to a γ:δ T-cell receptor.

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Definitions:

Carbanion

A negatively charged ion (anion) of carbon that carries a lone pair of electrons, making it extremely reactive in organic reactions.

Hydride Shift

A rearrangement reaction where a hydride ion (H-) moves from one carbon atom to another within a molecule.

Methyl Shift

A rearrangement reaction where a methyl group in a molecule moves from one carbon atom to an adjacent carbon.

Zaitsev's Rule

A rule in organic chemistry that predicts the more substituted alkene as the major product in elimination reactions.