It primarily occurs in the leaves
They are used for them to adapt to the environment
Answer:
B I think sorry if I am wrong
Answer:
cardiac
Explanation:
An electrical stimulus is generated by the sinus node (also called the sinoatrial node, or SA node). This is a small mass of specialized tissue located in the right upper chamber (atria) of the heart. The sinus node generates an electrical stimulus regularly, 60 to 100 times per minute under normal conditions.
