. As arteries extend outward they decrease in thickness until they turn into microscopic vessels known as_ ((frog dissection))

ANSWER: The correct answer is CAPILLARIES

EXPLANATION: Arteries are the muscular wall tube that carries oxygenated blood from the heart to other part of the body. The arteries extend outward from the heart, and form capillaries.

The capillaries are hairlike thinnest blood vessels, that helps to join the arteries and ventricles together. The blood in the arteries extends to the capillaries of the organs where the blood is supplied, and then moves out to from the organ via the ventricles.

The capillary starts from the part of the arteries that are very thin.

•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: