In most hypotheses of early earth and the formation of life, it is accepted that the atmosphere was a reducing one. this means that there was an abundance of methane, ammonia, and water vapor, but there was an absence of significant amounts of oxygen gas. based on this assumption, what was likely the first metabolic activity to harness atp to evolve in primitive cells?
a) photosynthesis, as plants evolved before animals
b) cellular respiration, as this generates the most atp
c) glycolysis, as this does not require organelles not oxygen
d) calvin cycle, as glucose was required by all cells for metabolism

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?