Achimpanzee using a long twig to catch termites is an example of a(n)
a. external stimulus
b. patterned behavior
c. learned behavior
d. innate behavior

lizards have adapted to life in the desert. some desert lizards have toes with spiny scales to them run across the sand without sinking. some use the sand to hide from predators, or to search for small animals that they prey upon.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.