Answer:
Chemical reactions often involve changes in energy due to the breaking and formation of bonds. Reactions in which energy is released are exothermic reactions, while those that take in heat energy are endothermic.
Explanation:
The answer to your question is A
Answer:
Nucleus and mitochondria. Organism.
Explanation:
The two main organelles are the nucleus and the mitochondria . The nucleus is boss of the factory(controls everything). The mitochondria is the power house of the cell (provides the energy). Humans are organisms (made of organs systems working together) . Another example is plants they are also organisms