the diagram below shows a cross section of a plant leaf how does the structure marked X contribute to the survival of the plant?

the answer is otpion c) understanding

he wants to be heard one more time. he wants to be understood. he needs the truth one more time.

oxygen +1 most likely

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.