The Second Heart Sound (S₂)occurs Because of the Closure of The

question 17

Multiple Choice

The second heart sound (S₂) occurs because of the closure of the:

• A) Aortic valve
• B) Tricuspid valve
• C) Aortic and pulmonic valve
• D) A and B

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Definitions:

Cytoplasmic Projections

Extensions of the cell's cytoplasm, such as cilia and flagella, that can move the cell or move fluids past the cell.

Axopods

Long, slender, and sometimes retractable projections of some eukaryotic cells involved in locomotion or feeding.

Flagellated Cells

Cells possessing one or more flagella, which are long, whip-like structures that can propel the cells through liquid environments.

Red Algae

A large group of algae known for their reddish color, which is caused by phycoerythrin; they are mostly marine and play a role in coral reef ecosystems.