All of These Might Have Been Observed in the Common

question 72

Multiple Choice

All of these might have been observed in the common ancestor of chondrichthyans and osteichthyans, except

• A)a mineralized, bony skeleton.
• B)scales.
• C)lungs.
• D)gills.
• E)a swim bladder.

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Definitions:

Sodium Ion

A positively charged ion (Na+) essential for various physiological functions, including nerve impulse transmission and fluid balance in the body.

Calcium Ions

Positively charged calcium atoms (Ca2+) that play vital roles in various biological processes, including muscle contraction, neurotransmission, and blood clotting.

Unequal Ion Concentration

Refers to a difference in the concentration of ions across a membrane, leading to potential differences and driving forces for ion movement.

Sodium-chloride Pump

A mechanism, particularly in the kidney cells, that helps in the reabsorption or excretion of sodium and chloride ions.