Approximately What Proportion of All Species That Ever Existed on Earth

question 121

Multiple Choice

Approximately what proportion of all species that ever existed on earth are still in existence?

• A) about 61%
• B) about 31%
• C) about 7.5%
• D) less than 1%
• E) about 19%

Recognize the consequences of human activities on the phosphorus cycle and algal blooms in freshwater ecosystems.

Know the role of different bacteria in the nitrogen cycle and their importance in ecosystem nitrogen replenishment.

Analyze the trade-offs in ecological services due to large-scale industrial agriculture.

Appreciate the importance of pollinators and other ecosystem services for human well-being.

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Definitions:

Fight-Or-Flight

A physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival.

Parasympathetic

Part of the autonomic nervous system that conserves energy and slows the heart rate, among other functions.

Splanchnic Nerves

Nerves that convey information about the nutrient contents of the stomach to the brain and are responsible for providing autonomic nervous system control to the abdomen.

Collateral Ganglia

Collections of nerve cell bodies located in the peripheral autonomic nervous system, involved in transmitting nerve signals to organs.