A large
majority of the undiscovered species are predicted to be what kind of organisms?

answer; the tunica intima also called tunica interna, consists of elastic fibers,connective tissue and smooth muscle cells;

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.

barometer is an instrument used to measure the atmosphere's pressure. the high air pressure relative to average levels is associated with calm and sunny weather. on the other hand, low pressure is associated with bad weather, high winds, and rain. 

genetic variations are caused by mutations which are random in the population