Scientists theorized that all ecosystems need sunlight as an energy source. What has been discovered on the ocean floor that has challenged this theory?
A
ecosystems based around hydrothermal vents that rely on the vents' heat and chemicals for energy
B) ecosystems that get their energy from nuclear energy sources found on the ocean floor
ecosystems that rely on energy from bottom-feeding fish
D ecosystems that do not need any energy source

Me brainliest 1. what does a red shift mean? blue shift? 2. describe the big bang theory. according to this theory, how old is the universe? 3. scientists believe the universe is expanding. what is the evidence that supports this? 4. describe a nebula.5. describe the 3 types of galaxies. what is a barred spiral galaxy? 6. what is a light year? how far is alpha centauri from earth? 7. describe the universal law of gravitation. be sure to include gravitational force between two objects.8. describe the planets’ orbits around the sun.9. what is the asteroid belt? where is it located? 10. describe rotation and revolution of earth. what determines an earth day and year? 11. how do galaxies exist? 12. compare and contrast the inner and outer planets.13. what causes the seasons?