The Accompanying Figure Shows the Results of Jackson and Cheetham's

question 4

Multiple Choice

The accompanying figure shows the results of Jackson and Cheetham's studies on fossil and living cheilostome bryozoans.What can you infer from these diagrams?

• A) Species of bryozoan have tended to persist with very little morphological change.
• B) Bryozoans have unusually low genetic diversity.
• C) Bryozoans predominantly evolve by phyletic transformation, or anagenesis.
• D) Bryozoans have suffered heavily from extinction events on islands.
• E) It is hard to define bryozoan species because of the presence of so many intermediate forms.

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Definitions:

Splanchnic Nerves

Nerves that convey information about the nutrient contents of the stomach to the brain and are responsible for providing autonomic nervous system control to the abdomen.

Collateral Ganglia

Collections of nerve cell bodies located in the peripheral autonomic nervous system, involved in transmitting nerve signals to organs.

Paravertebral Ganglia

Nerve cell clusters found alongside the vertebral column, involved in the autonomic nervous system's sympathetic division.

Vagus Nerve

The tenth cranial nerve, which innervates various organs, including the heart, lungs, and digestive tract, and plays a critical role in autonomic functions.