The kidneys are organs in the human body that have multiple functions. One critical function is to maintain the pH of the blood at a precise level. What biological process involves the maintenance of a constant internal environment?
A)
homeostasis
B)
lysis
metabolism
D)
osmosis

the cell theory states that all living things including animals, as well as plants, are made of cells.

yes we can.   a lady urinates from her urethra.

for example, no new evidence will demonstrate that the earth does not orbit around the sun (heliocentric theory), or that living things are not made of cells (cell theory), that matter is not composed of atoms, or that the surface of the earth is not divided into solid plates that have moved over geological timescales .