Final answer:
Rainforests provide vital ecosystem services such as water cycle regulation, air and water purification, oxygen production, carbon sequestration, and biodiversity conservation, which may lead to medical and biological breakthroughs.
Step-by-step explanation:
The rainforest provides a plethora of ecosystem services that are crucial for the sustainability of our planet. These include regulation of the water cycle, which forests play a key role in through processes like transpiration and precipitation. Tropical rainforests contribute to the purification of air and water, as well as the production of oxygen and removal of greenhouse gases. Another vital service is the biodiversity it houses; a source of potential medical and biological breakthroughs. The forest also aids in pollination of crops, filtering pollutants from water, and providing a habitat for innumerable species, which can help in seed dispersal and insect predation. Unfortunately, deforestation threatens these services by destroying the habitats essential for these processes and the species that perform them.