Hola awesomites!!
So, this is answer of our previous question. Lets have a look into it.
Q1)Which of the following features is not shared between T cells and B cells
a)Antigen specific Receptors
b)Class 1 MHC expression
c)Positive selection during development
d)All of the above
Answer is
C) Positive selection during development
Explanation:
Positive selection:
Site is thymic cortex.
-T cells having affinity for MHC molecules are selected since T cells having affinity for MHC molecules can interect with APC and one who don't have recognisation is killed
Negative selection:
Site:Thymic medulla
Selected T cells are sent to medulla,where there affinity for self antigens are tested.If the have affinity they are programmed to death.
Incase of B cells,if they recognize self antigens they do not undergo death instead there receptors are changed by the process called as "Receptor editing" .If receptor editing dose not take place,then apoptosis takes place.This is negative selection of immature B cells. B cells negative selection occurs in the bone marrow
Both T-cell and B-cell have TCRs and BCRs respectively.
Class I MHC is expressed on both T cells and B cells..
Stay awesome:)
~Ojas
good post , however there are several grammatical errors:
ReplyDelete"and one who don't have recognisation is killed" There is no such word "recognisation" in English. "The ones that are not recognized are killed," would have been correct. I believe you were trying to use the word"recognition," but it doesn't fit in the sentence construction.
where "there" affinity for self antigens are tested.If the have affinity they are programmed to death.
The correct word is "their", which indicates possession: "there" indicates a place. "they are programmed to die" would also be more correct English usage.
Thanks for edit :)
ReplyDelete