The Important Innovation That Evolved from the Gill Arches of Jawless

question 109

Multiple Choice

The important innovation that evolved from the gill arches of jawless fishes and is retained by chondrichthyans, ray-finned fishes, coelacanths, lungfishes, and tetrapods is

• A) heavily armored skin.
• B) the jaw.
• C) fins.
• D) the ability to swim.
• E) the vertebral column.

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Definitions:

Peptide Hormones

Short strings of amino acids that act as signaling molecules, regulating physiological processes in the body.

Cyclic AMP

Cyclic AMP (cAMP) is a second messenger important in many biological processes, transmitting the effects of hormones like adrenaline and glucagon at the cellular level.

Oxytocin

A hormone and neurotransmitter involved in childbirth and lactation, also associated with empathy, trust, sexual activity, and relationship-building.

Positive Feedback

A mechanism in which an output in a system intensifies the response or increases the production of that output.