The function of IgD on the surface of B cells is to:

a) present antigen to helper T cells.

b) present antigen to cytotoxic T cells.

c) bind antigen so that it can be internalized by the B cell and presented to helper T cells on class II MHCs.

d) bind antigen so that it can be internalized by the B cell and presented to cytotoxic T cells on class I MHCs.

Two true-breeding pea plants were crossed. one parent is round, terminal, violet, constricted, while the other expresses the respective contrasting phenotypes of wrinkled, axial, white, full. the four pairs of contrasting traits are controlled by four genes, each located on a separate chromosome. in the f1 only round, axial, violet, and full were expressed. in the f2, all possible combinations of these traits were expressed in ratios consistent with mendelian inheritance. (a) what conclusion about the inheritance of the traits can be drawn based on the f1 results? (b) in the f2 results, which phenotype appeared most frequently? what mathematical expression predicts the probability of occurrence of this phenotype? (c) which f2 phenotype is expected to occur least frequently? what mathematical expression predicts this probability? (d) in the f2 generation, how often is either of the p1 phenotypes likely to occur? express your answer as a fraction (example: 3/16).

The observations of hooke and van leeuwenhoek documenting the existence of microscopic cells formed the basis of what important theory? a. the cell theory stating that all living things are composed of cellsb. the theory of spontaneous generation, which held that life forms could arise spontaneouslyc. the theory of chemotherapy, or use of antimicrobials to destroy pathogenic organismsd. the germ theory of disease and causative agents

What macromolecule is produced during translation? a. carbohydrate b. rna c. dna d. protein