Which of the following statements about prescribed burns is true? a. Prescribed burns will always have detrimental effects on ecosystems, but should be used to protect homes. b. Prescribed burns are necessary for preventing natural wildfires. c. Prescribed burns can help maintain healthy ecosystems. d. None of the above

Animal bodies (and even plant bodies for that matter) are complex enough that life couldn't exist without enzymes. enzymes are usually large, complex biological catalysts that are expensive to make. enzymes speed up the rate of chemical reactions without being used up during the reaction (they can be reused many times). they are highly specific in the reactions they regulate. knowing what enzymes are and how they function, why does this explain why complex life forms could not exist if there were no enzymes.

Which part of the cell is affected by the movement of molecules through diffusion, osmosis and active transport?

In which state was more than 100 billion tons of coal mined in 2005?