If the Beating Heart Makes a ʺLub-Dupʺ Sound, the ʺDupʺ

question 101

Multiple Choice

If the beating heart makes a ʺlub-dupʺ sound, the ʺdupʺ sound is caused by

• A) the apex of the heart hitting the anterior chest wall.
• B) vibrations that result from the semilunar valves slamming shut.
• C) a stenotic atrioventricular valve.
• D) the large force of the contracting ventricles.

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Definitions:

Adaptive Significance

Refers to the beneficial features of traits that have evolved through natural selection to solve specific problems in an organism's environment.

Constant Light (LL)

An environmental condition in which organisms are exposed to uninterrupted light, used in research to study circadian rhythms and biological clocks.

Circadian Rhythm

The built-in, roughly 24-hour cycle of physiological processes that organisms follow, including sleeping and feeding patterns, which responds to light and darkness in an organism's environment.

Cricket Calling

The production of sounds by male crickets, typically for attracting females and deterring other males, through the rubbing of their wings together.