Earth's atmosphere, oceans, and continents, began to form during the first several hundred million years of

A. Precambrian time

B. Paleozoic era

C. Mesozoic era

D. Cenozoic era

What is the one way nitrogen may be returned to the air?

Enzymes are a special type of protein. true false

What is the Earth's outermost layer? A. the inner core B. the mantle C. the outer core D. the crust

Which resource is a nonrenewable resource? fresh water maple trees solar energy precious metal

What will happen if a bacterial cell is placed in 10% NaCl with penicillin? The cell will undergo osmotic lysis. Penicillin will diffuse into the cell. Water will enter the cell. The cell will plasmolyze.

Describe the function of a chemical synapse.

What are the types of friction

Describe the range of variation in the nervous systems of invertebrates

How does volcanic ash form

What is one effect of immigration on a population living in an ecosystem? A) the competition for resources will increase. B) more animals will leave the ecosystem. C) biodiversity will decrease. D) the population will decrease.