Australopithecines,the First Hominins,are Thought to Have Evolved About __________ Years

question 110

Multiple Choice

Australopithecines,the first hominins,are thought to have evolved about __________ years ago.

• A) 100 million
• B) 150 million
• C) 90 million
• D) 4 million
• E) 100 thousand

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Definitions:

Venous Tone

The degree of constriction experienced by the veins, influencing the volume of blood held within venous reservoirs and blood pressure.

Medulla Oblongata

The lower portion of the brainstem that regulates vital functions, such as heart rate and breathing.

Vasomotor Center

Area within the medulla oblongata that regulates the diameter of blood vessels by way of the sympathetic nervous system.

Blood Colloid Osmotic Pressure

Pressure exerted by plasma proteins on capillary walls, which helps to maintain the water balance between blood and interstitial fluid.