With reference to the planet Earth, consider the following statements : 1. Rain forests produce more oxygen than that produced by oceans. 2. Marine phytoplankton and photo-synthetic bacteria produce about 50% of world's oxygen. 3. Well-oxygenated surface water contains several folds higher oxygen than that in atmospheric air. Which of the statements given above is/are correct?

Statement 2 is correct because marine phytoplankton and photosynthetic bacteria are responsible for producing approximately 50% to 80% of the Earth's oxygen through photosynthesis. Statement 1 is a common misconception; although rainforests are highly productive, the vast surface area of the oceans ensures they produce significantly more total oxygen. Statement 3 is incorrect because the concentration of oxygen in the atmosphere (roughly 21%) is much higher than in water, where oxygen has low solubility and is measured in parts per million. This question tests the core concept of the global oxygen cycle and the relative biological productivity of marine versus terrestrial ecosystems.