Vascular Plants Are Thought to Be the Result of a Single

question 16

Multiple Choice

Vascular plants are thought to be the result of a single evolutionary event: the evolution of a wholly new cell type, the tracheid.This cell type

• A) provides a mechanism for the storage of a new type of carbohydrate, starch.
• B) is the first cell type to contain chloroplasts.
• C) permits fertilization in the absence of water, thus permitting plants to invade dry habitats.
• D) forms the sporangium.
• E) is the principal water-conducting element of the xylem in all early vascular plants.

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Definitions:

Positive Punishment

The addition of a stimulus to decrease the probability that a behavior will recur.

Primary Reinforcement

A term in behavioral psychology that refers to something that is naturally rewarding or satisfying, like food or water, that reinforces a behavior.

Variable Interval

A schedule of reinforcement where a response is rewarded after an unpredictable amount of time has passed, used in operant conditioning.

Fixed Ratio

A schedule of reinforcement where a response is rewarded only after a specified number of responses.