Answer:
The correct answer will be option-C
Explanation:
The rhythm of the heartbeat is controlled by the pacemaker of the heart called the sino-atrial node.
The SA node generates action potentials which trigger the contraction and relaxation of the atrium and ventricles. The membrane potential generation initiates by the depolarization of the cell membrane when the L type of Ca⁺² ions opens up and calcium ions enter the cell.
This depolarizes the cell until the potential threshold is reached which lies between the -40 and -30 mV.
Thus, Option-C is the correct answer.
C is the answer. Due to the current state of the world economy; people, if left to their own devices, would fish as much as possible so they can sell their fish to make money. Current technology means we can catch as many fish as we want (trawlers etc.). The problem with this is that there is only a finite amount of fish in the sea. If we were to fish them without limits in place, we could cause them to go extinct.
<span>There are two structures that would be found at a passive continental margin. These structures are continental shelves and continental slopes.</span>
Activation energy is the minimum quantity of energy that the reacting species must possess in order to undergo a specified reaction.
for example , striking a match on the side of a matchbox provides the activation energy, in the form of heat produced by friction.
Primary= peptide bonds
secondary= hydrogen bond
tertiary= weak bonds, hydrophobic, disulfide bridges, salt bridges
quaternary= between polypeptides
