$(a)$ In what ways does the water cycle help marine organisms?
$(b)$ 'The biosphere is a dynamic but stable system'. Justify this statement.

(N/A) - Water is capable of dissolving a large number of substances.
- Water flows through or over rocks containing soluble minerals.
- Some of these minerals dissolve in the water.
- Consequently,rivers carry many nutrients from the land to the sea.
- These minerals are essential for the survival and growth of marine organisms.
$(b)$ - The biosphere is characterized by a constant interaction between biotic (living) and abiotic (non-living) components.
- These interactions involve the continuous transfer of matter and energy between the different components of the biosphere.
- This cycle of matter and energy flow maintains the balance of the ecosystem,making it a dynamic yet stable system.