Which of the following structures are vestigial? wings in birds
coccyx (tailbone)
pelvises in snakes
eyes in cave-dwelling fish
male nipples
dog dewclaws
femurs (leg bones)
appendix
hip bones in whales
female nipples
pelvises in mammals
wisdom teeth
hip bones in cats

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.

answer; microsoft;

carbon traps heat so more of it makes it hotter causing global warming. during the ice age carbon levels in the atmosphere were low so it got very cold. so the common things between them is carbon levels in the atmosphere.