Which statement about the specific immune response is FALSE?
A..Each T or B cell has antigen receptors for only one specific antigen.
B..T and B cells recognize antigens by using antibodies bound to their surface C..membranes. Unique antigen receptors are created by genetic recombination.
D..Antigens must be presented by an MHC molecule for T and B cells to recognize them.
E..All cells express MHC-I molecules, but only antigen-presenting cells express MHC-II molecules.

Which statements best describe the differences or similarities between a comparative investigation and an experimental investigation? check all that apply. experimental investigations are best for showing cause-and-effect relationships, while comparative investigations do not necessarily show this type of relationship. comparative investigations are often impractical and unrealistic, while experimental investigations are the most practical and realistic kinds of investigations. comparative investigations allow for the use of a wide range of variables but do not have a control group, while experimental investigations involve variables that can be controlled. both experimental investigations and comparative investigations are designed to answer scientific questions. both experimental investigations and comparative investigations focus on making observations rather than collecting new data.