Jaws Appear to Have Evolved from

question 73

Multiple Choice

Jaws appear to have evolved from

• A) the fusion of many bony elements found in the skin of the neck region of jawless ancestors.
• B) a large, bony shield that protruded from between the base of the pectoral fins.
• C) modification of a disk of bones surrounding the mouth in lampreys.
• D) skeletal rods that supported gill slits near the mouth.

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Definitions:

Taxa

Groups of one or more populations of organisms classified together, representing categories used in biological taxonomy such as species, genus, or family.

Monophyletic

Pertaining to a group of organisms that consists of all the descendants of a common ancestor.

Polyphyletic

A term describing a group of organisms that are classified together but do not share a recent common ancestor.

Homoplastic

Exhibiting similarity in appearance due to convergent evolution rather than ancestry.