Which of the following was used in the 1940s to analyze amino acids that make up proteins? a. genetic engineering. b. chromatography. c. radioactive tracers. d. x-ray diffraction

Many animals cannot sweat to maintain a stable body temperature. what is one other way animals can cool down?

Which spheres are involved when sedimentary rocks formed from parts of seashells at the bottom of the ocean? a.) biosphere, atmosphere, geosphereb.) geosphere, hydrosphere, biosphere c.) geosphere, exosphere, hydrosphered.) hydrosphere, biosphere, atmosphere

The two main stages of cell division are called