Explain how the level of oxygen and carbon dioxide in the blood will trigger the respiratory center

What are genotypes? what are phenotypes?

What can be said about farmers in highly developed countries? a) they have little or no negative impact on the environment. b) they practice subsistence agriculture. c) they are able to incorporate polyculture into their farming practices. d) they utilize organic farming techniques on a regular basis. e) they rely on large amounts of energy from fossil fuels.

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?