Gold is opaque and reflective. it has a

-glassy luster
-metallic luster
-dull luster
-pearly luster

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 is an important function of normal flora? a. aid with bone marrow production. b. crowd out pathogenic bacteria. c. destroy digestive track pathogens. d. manufacture iron in the bloodstream.

When a cell is in a solution that has the same concentration of water and solutes as its cytoplasm, the cell is said to be in a(n) solution. a. isotonic b. hypotonic c. hypertonic b. facilitated