The main function is A, secrete hormones
Answer:
ADP is converted to ATP for the storing of energy by the addition of a high-energy phosphate group. The conversion takes place in the substance between the cell membrane and the nucleus, known as the cytoplasm, or in special energy-producing structures called mitochondria.
Explanation:
Hope this helped Mark BRAINLEST!!
The answer is the letter B. Electrical signals.
*Our brain and body communicates with each other by sending messages in the form of electrical signals.
It is chloroplast I guess because once i read that mitochondria has not much importance in being an autonomous organelle
