Juan want to predict what alleles a puppy might inherit from two dogs that have the alleles DD and Dd. He makes a Punnett square like the one shown. Which of the following predictions about the puppy's alleles can Juan make using the model? D D

D DD DD

d Dd Dd

D- dominant d- recessive

A. It will have a 1/4 chance of inheriting one recessive allele.
B. It will have a 1/2 chance of inheriting one dominant allele.
C. It will have a 100% chance of inheriting one recessive allele.
D. It will have a 1/2 chance of inheriting two dominant alleles.

the answer is c. it will give up it's valence electron to the other atom.

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.