Bacteria and viruses : pathogens :: a.
cytotoxic T cells and macrophages : pathogens

b.
cytotoxic T cells and B cells : white blood cells

c.
B cells and T cells : mucous membrane cells

d.
helper T cells and cytotoxic T cells : skin cells

Name one similarity and one difference between the morphology of a brachiopod and a bivalve

What is a gene ? a) a section of a protein that codes for dna. b) the alternate version of a trait. c) the visible trait in the f1 generation. d) a section of dna that codes for a specific trait .

Where would you expect to see seedless plants, such as ferns and mosses? a. in a botanical museum, because they are all extinct b. low and close to the ground in a moist environment c. climbing high while circling the branches of another plant d. deeply rooted in a forest with a trunk that reaches 20 meters or more