Paleontologists Estimate That ________________

question 33

Multiple Choice

Paleontologists estimate that ________________.

• A)99% of all species that have ever existed are now extinct
• B)more than 99% of all species alive today have been discovered and described
• C)extinction is tied exclusively to human activities
• D)more species are alive today than ever before
• E)biodiversity is evenly spread over the earth's biomes

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Definitions:

Retinal Receptors

Light-sensitive cells located in the retina that are responsible for converting light into electrical signals, which are then interpreted by the brain as vision.

Voluntarily

Acting or done of one's own free will without external compulsion or coercion.

Eyeball

Slang for estimating or measuring something by sight without the use of instruments.

Synaptic Response

The process by which a neuron responds to neurotransmitters released by another neuron at the synapse.