What is an antigen?
a
σ
O
ο
A protein on the surface of red blood cells
A protein hidden inside red blood cells
A pathogen found in blood
The liquid containing blood cells
d.

Which term describes a normal value for something in the body? a. homeostasis b. set point c. feedback loop d. integration center

About __ of the mass of the cell is water

You want to cultivate some exotic plants at your farm. however, the climate is chillier than the temperature range favorable to the crop. which is the best method to use for the cultivation of this exotic crop? a. use a crop rotation method b. use a lot of fertilizer c. prepare the seed bed properly d. use a greenhouse e. use irrigation