Question 8

B, C, and D depend directly on solar energy.

The processes that depend directly on solar energy are the water cycle, photosynthesis, and atmospheric circulation. Each of these processes relies on energy from the sun to function effectively and sustain life on Earth.

A) Seafloor spreading

Seafloor spreading is a geological process that occurs at mid-ocean ridges where tectonic plates move apart, leading to the creation of new oceanic crust. This process is driven by geothermal heat from the Earth’s interior rather than solar energy, making it incorrect in the context of solar dependency.

B) The water cycle

The water cycle is heavily influenced by solar energy, as it drives processes such as evaporation and transpiration. Sunlight heats water in oceans and other bodies, causing it to evaporate into the atmosphere, where it eventually condenses and precipitates back to the surface, illustrating a direct dependency on solar energy.

C) Photosynthesis

Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy from the sun into chemical energy in the form of glucose. It is fundamentally reliant on solar energy, which is captured by chlorophyll and used to transform carbon dioxide and water into sugars and oxygen.

D) Atmospheric circulation

Atmospheric circulation is driven by the uneven heating of the Earth's surface by solar energy. This differential heating leads to wind patterns and climate systems, indicating a clear dependence on solar energy for the movement of air and weather phenomena.

Conclusion

The processes of the water cycle, photosynthesis, and atmospheric circulation are all fundamentally reliant on solar energy, making them the correct choices. In contrast, seafloor spreading does not involve solar energy but is instead a result of geological activity, which underscores why it is not included as a correct answer.