The Figure Shows a Hypothesis for the Evolution of Visual

question 28

Multiple Choice

The figure shows a hypothesis for the evolution of visual opsins in tetrapods. At the tips, each triangle represents a particular visual pigment found in a modern tetrapod. Along ancestral branches, the hypothesized evolutionary history of these opsins are shown. Which of the following is true of this evolutionary hypothesis?

• A) Squamate reptiles and birds have maintained the ancestral opsins.
• B) Humans have lost a single opsin relative to the tetrapod ancestor.
• C) New world primates lost two opsins, but then gained a new one.
• D) Opsins have been gained and lost in every tetrapod lineage.

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Definitions:

Energized

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Start Button

A control interface, typically a button, used to initiate a process or operation in machinery, software applications, or devices.

Preset Count

A predetermined value used in counting applications to trigger an event when a counter reaches this value.

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Data or signals received by a system, device, or computational process for processing or manipulation.