If a restriction site is altered, a higher molecular weight band will be observed.
Restriction enzymes are proteins synthesized by bacteria to protect itself against foreign DNA. These enzymes cut DNA at specific places.
This enzyme is used to detect mutations in the genome, particularly those at the sites of action of these restriction enzymes. A healthy subject is compared with the patient who is supposed to have cystic fibrosis. If their DNA migration is different, it means that their DNA is different and that there is a mutation at the restriction sites.
Speed of light is usually time and space so probably C
I can't read the paper, so all I can say is read Darwin's Survival of the Fittest and you will understand evolution.
