Following the Reptilian Extinctions at the Close of the Mesozoic,two

question 98

Multiple Choice

Following the reptilian extinctions at the close of the Mesozoic,two groups of mammals,the marsupials and ________,evolved.

• A)eukaryotes
• B)cephalopods
• C)trilobites
• D)placentals
• E)stromatolites

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Definitions:

Discriminative Stimulus

A specific stimulus in the presence of which a particular response is more likely to be reinforced, and in the absence of which a response is not likely to be reinforced.

Primary Reinforcer

An innately satisfying stimulus, such as food or warmth, that does not require learning to become desirable and motivates behavior.

Conditioned Reinforcer

A stimulus or event that gains its reinforcing power through its association with a primary reinforcer.

Colonization

The process by which a central system of power dominates the surrounding land and its components, often involving the settlement of its population to new territories.