Refer to the Phylogenetic Tree Below Showing the Phylogenetic Relationships

question 39

Multiple Choice

Refer to the phylogenetic tree below showing the phylogenetic relationships among eight species.Red dots show the appearance of derived traits. According to the phylogenetic tree, salamanders and mice share _______ of the listed synapomorphies.

• A) none
• B) one
• C) two
• D) three
• E) at least four

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Definitions:

Oligodendrocyte

A type of glial cell in the central nervous system that produces myelin, a substance that insulates nerve fibers to enhance signal transmission.

Myelin Sheath

A layer of protective insulation that covers nerve fibers, enhancing the speed and efficiency of electrical signal transmission along the nervous system.

CNS

Central Nervous System, comprised of the brain and spinal cord, responsible for processing and coordinating sensory information and motor commands.

PNS

Stands for Peripheral Nervous System, which includes all the nerves outside of the brain and spinal cord.