The Evolutionary Tree Below Illustrates the Hypothesized Relationships Among the Six

question 28

Multiple Choice

The evolutionary tree below illustrates the hypothesized relationships among the six kingdoms and the three domains.
Many biologists have suggested revising the kingdom Protista. One current problem with the protists, as shown in the figure, is that

• A)protists are single-celled organisms and should be in a separate domain.
• B)the cells of protists contain nuclei and organelles.
• C)some protists, like the red and green algae, are more closely related to plants than to the other protists they are currently grouped with.
• D)chlorophyll would need to evolve independently several times to account for the distribution of photosynthetic groups.

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Definitions:

Drive Reduction

A motivation theory that suggests behavior is motivated by the desire to reduce internal drives of tension or arousal that arise from unmet needs.

Pleasure Principle

A psychoanalytic concept suggesting that individuals seek pleasure and avoid pain to satisfy their biological and psychological needs.

Optimal Arousal

A theory suggesting there is a level of arousal that is ideal for facilitating optimal performance on a task or activity.

Incentives

Rewards or stimuli that motivate individuals to perform actions or behaviors, often used to encourage desired outcomes.