William gaskin is scheduled for a procedure tomorrow at the diagnostic center. he will receive an infusion of a radiopaque contrast medium, barium sulfate, into the rectum. the contrast medium will remain in the lower intestinal tract while x-ray films are obtained of the lower gi tract. this procedure is called .

The correct answer is: barium enema.

Barium enema is technique used for detection of  changes or abnormalities in the large intestine-colon via X-rays so it is often called  colon X-ray. Barium envelops the lining of the colon so it is clear to see silhouette of the colon. This type of diagnosis is used in the case of abdominal pain, rectal bleeding, chronic diarrhea..

cats appear to have glowing cat eyes because the back of their eyeballs includes a special reflective surface called the tapetum lucidum. this lets them see better during the night, giving them a much better vision.

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation: