You are trying to determine the mode of inheritance for the mutant curly-winged phenotype in Drosophila. You cross pure-bred wild-type flies with pure-bred mutant (curly-winged) flies and notice that all of F1 has curly wings. You make the scientific hypothesis that the curly-winged phenotype is autosomal dominant to the wild-type wing phenotype. a. If your scientific hypothesis is correct, what ratios would you expect to see in your F2 generation?

The correct answer is - In F2 generation we should get a 3:1 ratio of phenotypes. 3 curly dominant, 1 wild type recessive.

Explanation:

In the given case, the cross between pure-bred wild-type flies with pure-bred mutant (curly-winged) flies and it is found that in F1 generation all offsprings are curly wings which means curly wings are dominant over wild-type.

let assume w gene is responsible for wild type and W gene is responsible for the curly wings which is dominant over wild type

     W   W

w    Ww  Ww

w  Ww   Ww

now on self crossing

     W   w

W   Ww  Ww

w   Ww  ww

In f2 generation there are 75% chances of the curly wing and 25% chances of wild type or the ratio of phenotype would be 3:1

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.