Which is the central element for all living things

The health, management and conservation of biodiversity, is a challenge facing ecosystems worldwide. the major factors that affect the health and function of the great barrier reef are climate change and pollution. which question investigates the effects of a biotic factor on the reef ecosystem?

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

Where are the strongest jet streams located?