drugs relax smooth muscle in the walls of the arteries, cause the arteries to dilate, and are used to treat hypertension.

Peripheral vasodilators

Explanation:

Peripheral dilators are a form of vasodilators that are involved in the dilation of the most distal parts of the vascular system such as the venules and arterioles. It does this by relaxing the smooth muscle of the blood vessels that are wide open, therefore making it easier for the heart to pump blood through  blood vessels and also the whole body.

In the treatment of hypertension, the peripheral dilators lower blood pressure by decreasing the total peripheral resistance of the arteries. In addition to the treatment of hypertension, they are also used in the treatment of heart failure and acute myocardial infarction.

An example is isoxsuprine.

parasites can detrimentally affect their host, but also must not allow their host to die before they can complete their life cycle. some parasites have complex life cycles with many different hosts, and have had to find ways of persisting in many different environments during the change from one host to another. ectoparasites live outside the body of the host, and can more easily  disperse, but are  more exposed to predators, parasites, parasitoids. endoparasites live inside the body of the host, and are therefore protected from the outside environment. but they can be  attacked by the host's immune system. they have therefore developed  mechanisms for dispersal such as  complex life cycles.

this is true, assuming that the allele is completely recessive and incomplete dominance is not a factor.