Which of the following provides the best example of how comparative embryology supports the theory of evolution? a. humans do not lay eggs as birds do, but birds produce yolk sacs instead of embryos, suggesting birds evolved later than humans. / b. humans have a tailbone that is not visible during embryonic development, which suggests that humans evolved to not depend on their tailbone serving a useful purpose. / c. humans do not have gills as fish do, but human embryos have gill slits, suggesting humans and fish share a common evolutionary ancestor. / d. humans have embryonic cells that dev

answer: b: experiments that showed that all cells are similar in how they metabolize and in their composition

explanation:

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.