Which of the following best explains why studying ocean microbes is important for understanding the biosphere?

• A. Ocean microbes play a crucial role in global nutrient cycling and carbon sequestration.
• B. Ocean microbes have no significant impact on the Earth's ecosystems.
• C. Ocean microbes are responsible for the majority of atmospheric oxygen depletion.
• D. Ocean microbes are the primary cause of most human infectious diseases.

Answer: (A)

Verified step by step guidance

1. Understand the role of microbes in the biosphere, which includes their involvement in nutrient cycling, energy flow, and ecosystem functioning.
2. Recognize that ocean microbes, such as phytoplankton and bacteria, contribute significantly to global processes like carbon fixation and nutrient recycling.
3. Recall that ocean microbes produce a large portion of the Earth's oxygen through photosynthesis, impacting atmospheric composition positively rather than depleting oxygen.
4. Evaluate the incorrect options by considering the ecological impact of ocean microbes: they are not the main cause of human infectious diseases, nor do they have no impact on ecosystems.
5. Conclude that the best explanation is that ocean microbes are vital for global nutrient cycling and carbon sequestration, which are key to maintaining the health and balance of the biosphere.