The Common Ancestor of the Protostomes Had a Coelom

question 24

Multiple Choice

The common ancestor of the protostomes had a coelom. What does this suggest?

• A) All lophotrochozoans have a coelom.
• B) There are no pseudocoelomates within the protostomes.
• C) There are no acoelomates within the protostomes.
• D) The body cavity evolved before the lophophore.

---

Definitions:

Variable Ratio

A reinforcement schedule where a response is rewarded after an unpredictable number of responses, making it a powerful method for conditioning stable and high rates of responding.

Reinforcement

In operant conditioning, a consequence that will strengthen an organism's future behavior whenever that behavior is preceded by a specific antecedent stimulus.

Responses

Reactions or behaviors produced by an organism in response to a specific stimulus or situation.

Continuous Reinforcement

is a method of learning where a desired behavior is reinforced each time it occurs, leading to faster acquisition of the behavior.