Mel is a retired stockbroker who enjoys mentoring children at the local ymca in the use of computers. he is demonstrating the psychosocial stage of:

surface mining destroys mountain tops, landscapes, forests and wildlife habitats. on top of that, it leads to soil erosion and destruction of agricultural land. the landscape changes can also disrupt river channels and streams, which leads to flooding. which, can destroy plant life and other animals as well.

explanation:

the answer would be 2, if crossing over doesn’t occur 2 out of 4 of the daughter cells will have that allele.

hope this : )

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.