Pacemakers maintain the heartbeat in people who suffer from certain defects. The function of an artificial pacemaker is to send electrical impulses that will contract the heart muscles and regulate the pumping of the heart. Which condition could be corrected by a pacemaker? A.
The individual’s sinoatrial node ceases to function.
B.
The individual’s central nervous system fails to signal the heart to contract and relax.
C.
The individual’s arteries are blocked.
D.
The valves in the individual’s heart cease to function.

Which of the following is not a way in which a vascular plant's xylem and phloem are similar?

In the united states there are strict fishing seasons and limits, but not all countries enforce similar laws. in bangladesh there are few if any fishing restrictions. what might be the reason for less restrictions in smaller countries like bangladesh? a) the united states is the only country worried about overfishing. b) the united states wants to limit the supply of fish to increase the price. c) bangladesh and smaller countries have an unlimited supply of fish in their coastal waters. d) small countries, such as bangladesh, are practicing subsistence fishing, taking only the fish needed to survive.

Kudzu vines grow by climbing and wrapping around trees. trees covered by kudzu can die because they are starved of sunlight. what type of relationship exists between the trees and the kudzu growing on them?