Men have xy (or yx) chromosomes and women have xx chromosomes. x-linked recessive genetic diseases (such as juvenile retinoschisis) occur when there is a defective x chromosome that occurs without a paired x chromosome that is not defective. represent a defective x chromosome with lowercase x, so a child with the xy or yx pair of chromosomes will have the disease and a child with xx or xy or yx or xx or xx will not have the disease. each parent contributes one of the chromosomes to the child. complete parts a through d below. a. if a father has the defective x chromosome and the mother has good xx chromosomes, what is the probability that a son will inherit the disease? b. if a father has the defective x chromosome and the mother has good xx chromosomes, what is the probability that a daughter will inherit the disease? c. if a mother has one defective x chromosome and one good x chromosome and the father has good xy chromosomes, what is the probability that a son will inherit the disease? d. if a mother has one defective x chromosome and one good x chromosome and the father has good xy chromosomes, what is the probability that a daughter will inherit the disease?

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.

1. is geographic distribution

2 is increasing complexity

3 is transitional forms

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.