Answer:
Activation energy.
Here’s why:
All chemical reactions, even exothermic reactions, need a certain amount of energy to get started. This energy is called activation energy. For example, activation energy is needed to start a car. Turning the key causes a spark that activates the burning of gasoline in the engine.
Answer:
D.
Explanation:
Leaf cells are full of chloroplasts that contain chlorophyll, which enables plants to harness light energy through photosynthesis.
Root cells are elongated cells that absorb water and minerals from the soil.