Why is the concentration of this ligand for the NK-cell receptor CD94:NKG2A. on the target cell an effective measure of the presence or absence of classical MHC class I molecules?

Dendritic cells take up, process or present antigen by all of the following routes except Select one: a. receptor-mediated endocytosis of bacteria. b. macropinocytosis of bacteria or viruses. c. uptake of viruses using Toll-like receptor TLR9. d. cross-presentation from the MHC class II pathway to the MHC class I pathway. Oe. cross-presentation from incoming infected dendritic cells to healthy resident dendritic cells in secondary lymphoid tissue. Of. delivery of viral peptides from cytosol to endoplasmic reticulum during viral infection.

To what cell-surface receptor does the SARS-CoV-2 Spike protein bind? a. What type of genome does SARS-CoV-2 have? Please help explain in less than 5 sentences! Thank you

Addition of immunoglobulin G (IgG) specific for hemoglobin to a solution of hemoglobin results in the formation of a red precipitate. In contrast, addition of the Fab fragments from this antibody to hemoglobin results in no such precipitate. What could explain this difference in results? Treatment with papain produces Fab fragments with different antigen specificity than the original IgG molecule. IgG can simultaneously bind two different antigens, whereas an Fab fragment can only bind one antigen at a time. The Fab fragments preferentially bind to other Fab fragments rather than to hemoglobin. The hemoglobin molecule antibody-binding sites can bind IgG molecules, but cannot bind Fab fragments.

How is clonal selection related to the vast number of possible B and T-cell receptor binding conformations?  Draw a picture to illustrate your explanation.

¹C2²2S + E Sk3,0 where S is a T-cell of a particular variety, E is the corresponding (free, i.e. unbound) antigen, and C is a complex consisting of a T-cell bound to an antigen. Ø indicates the loss of T-cells due to decay as described above. 1. Let s, c and e be the concentration of S, C and E, respectively, in the body at time t. Assume that the background exposure to the disease results in a constant concentration eo of the antigen (free or bound) in the body. (b) (c) Consider the T-cell system. Assuming mass action kinetics, write down a system of ODEs for Show that ds dt S + E and k-1 where KM dc dt Show (include your working) that the 2D system of ODEs has two equilibria: (s*,c*) = (0,0) == : -k₁(eo — c)s + k_1c +2k₂c - k3s k-1+k2 k₁ (s*, c*) = ( k₂e0 k3 and KM, eo k2 dt' dt and KM = k₁(eo - c)s - k_1c - k₂c.