Question

Question 15 3 What process mediates the switch in lg constant region use from constant region u to constant region ? The switch in constant region use from u too is mediated by alternative promoter use The switch in constant region use from u to is mediated by DNA rearrangements The switch in constant region use from u to d is mediated by alternative mRNA degradation The switch in constant region use from u to is mediated by alternative splicing Question 16 3 pts How would Inhibition of phagocytosis activity affect antigen presentation in antigen-presenting cells? Would promote antigen presentation on MHCI Would inhibit antigen presentation on MHC II Would have no effect on antigen presentation Would promote antigen presentation on MHC II Would inhibit antigen presentation on MHCI

Answer 1

15. It has been seen during the antibody formation that the respective antibody or the immunoglobulin is having the constant and the variable region which can vary from different types of immunoglobulin. In the case of the immunoglobulin formation, it can bee seen that there are the different number of genes are present for the constant region and the variable region of this Ig formation.

Hence, in the case of the replacement of the "u" constant region with the delta or the vice versa then the gene rearrangement has to take place which will lead to the development of the newer Ig with the different constant region as mentioned in the question.

Thus, the answer to this question will be option "b" the switch of the constant region used for u to delta will be made through the DNA rearrangements

16. The phagocytosis has to take place for the presentation of the antigen to the immune cells such as the T-cells present in the blood of the organism. If the inhibition of the phagocytosis has been taken place then the similar adverse effect can be seen on the antigen presentation through MHC as well which are the platform for the antigen to present towards the immune cells. The main phagocytosis is depending on the uptake of antigen by the cells such as antigen presenting cells and that mostly presents the antigen through the help of the MHC II and which will be detected by the helper T-cells which are CD4+ in the surface biomarker.

Hence, the answer to this question will be option "b" would inhibit the antigen presentation on MHC II