What is the purpose of using genetic engineering to create edible vaccines?
a. to create vaccines that are capable of lasting years in the body to prevent future infections
b. to diminish negative side effects that may occur from administering vaccines with syringes
c. to enhance the flavor of vaccines so people are more likely to use them
d. to prevent widespread diseases in developing countries without using syringes

The answer is D. Vaccines are commonly administered intravenously through the use of syringes. However, studies have shown that there are challenges posed in developing countries that are related to this mode of administration of vaccines. One is the storage of syringes and their handling that reduces the sterility of the needles. This, therefore, increases the risk of the spread of diseases (such as hepatitis) by accidental parenteral infections through use of the needles during immunization exercises.

the answer is: they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur twice a year in the spring and fall.

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.