The expansion of gases takes place because of kinetic energy provided by heat which excites the molecules and causes them to move further apart. On cooling the atoms in a gas lose their energy and slow down coming closer together.
Sunlight. Based on the sunlight you receive you have three zones.
1. Sunlight zone- There is enough sunlight here and photosynthesis can happen. More than 90% of marine animals live in this zone.
2. Twilight zone- A small amount of light is here and no plants grow here. The fish who live here are the ones who have adapted to the little light. Lantern fish is an example.
3. Midnight Zone- 90% of the ocean is in this group. It is entirely dark and the temperature is freezing.
Mitochondria is the answer i believe
