I think it is C, but I could be wrong because I am taking an educated guess.
Answer:
A. Type of soil
Explanation:
A control experiment is the one that is used to checkmate the real experiment.
In this case, the fourth jar that contains the mixture of all the types of the soil is considered as the control experiment.
In a nutshell, it should be generally understood here that the type of soil serves as the control for the experiment.
Answer:
a) Both DdPp
b) Yes 3.8%
c) In plant A, the dominant allele D and P are coupled (DP, dp), In plant B they are in repulsion (Dp, dP).
Answer:
Helper T cells are arguably the most important cells in adaptive immunity, as they are required for almost all adaptive immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.
Explanation:
Helper T cells become activated when they are presented with peptide antigens by MHC class II molecules, which are expressed on the surface of antigen-presenting cells (APCs). Once activated, they divide rapidly and secrete cytokines that regulate or assist the immune response.
