The answer is b, for he is comparing the two rocks to find an age relative to the other
Answer:
Arteries at at a higher pressure than veins.
Explanation:
Arteries receive blood after the heart beats, putting them at a higher pressure. They are also thicker than veins as well.
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.
Answer:
D. The tubes allow water and nutrients to be transported throughout
the plant.
Explanation:
option D supports the description of the cells. The long , vertical tubes transport water and nutrients and are most likely xylem and phloem vessels.
option A is wrong since, chloroplasts inside the cell helps in absorbing sunlight.
option C is also wrong, because water loss is controlled by the stomata in the leaves and they are not long tubes.
option B could possibly be right but option D is better suited.
