4. What kind of material is found in the C horizon of a soil profile? O clay particles O mineral and organic matter O hardpan O partially weathered parent material
Astudent wants to test the hypothesis that fertilizer improves the growth rate of grass seeds. to test this hypothesis, the student put the same amount of grass seed in 3 containers with the same type of soil. the student measured the growth at the end of the week. all plants received equal amounts of water and sunlight. if you were asked to graph this data, what would you place on the x-axis? a. fertilizer b. water c. plant growth d. week one
Imagine a self-reactive t cell that has not undergone clonal deletion in the thymus (that is to say, it has escaped central tolerance). if it encounters self antigen in the absence of an infection or inflammation, what will happen to this self-reactive t cell? (select two answers) (a) the t cell undergoes clonal expansion. (b) the t cell gains effector functions. (c) the t cell undergoes apoptosis. (d) the t cell becomes activated. (e) the t cell becomes anergic.