Too little water concentrated in cells may make a person dehydrated. Being dehydrated may cause painful headaches and confusion. Which hormone and organ regulate water concentration? a. pituitary and glucagon
b. kidney and ADH
c. pituitary and ADH
d. pancreas and ADH

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

What controls activities within a eukaryotic cell?