Duchenne muscular dystrophy is an x-linked recessive disorder. what is the probability that a female offspring of the cross that is shown above would have a recessive allele for duchenne muscular dystrophy disorder? 0 percent 25 percent 50 percent 100 percent

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons

You have trained year for a marathon. in your first attempt to run a marathon, you decide that you want to complete this 26-mile race in 4-5 hours. a. what is the length of a marathon in kilometers (1mile= 1.6 kilometers). b. what would your average speed have to be to complete the race 4.5 hours? give your answer in kilometers per hour.