In Positive Selection, Thymocytes Undergo Apoptosis When

question 6

Multiple Choice

In positive selection, thymocytes undergo apoptosis when:
I-They do not interact with MHC molecules
II-They bind to MHC molecules with high affinity
III-They bind to MHC molecules with low affinity

• A) I only
• B) III only
• C) I and II
• D) II and III
• E) I, II, and III

---

Definitions:

GABA

A neurotransmitter in the brain that plays a key role in regulating nerve cell activity and is involved in reducing excitability and promoting relaxation.

Classical Conditioning

A learning process that occurs when two stimuli are repeatedly paired; a response that is at first elicited by the second stimulus is eventually elicited by the first stimulus alone.

Theoretical Position

A conceptual framework or approach within which a scientist operates, outlining the assumptions, principles, and methods pertaining to a particular field of study.

Phobias

Intense, irrational fears of specific objects, situations, or activities that lead to avoidance behavior.