Objections to the "Stepping-Stone" Hypothesis, Suggesting That Deep-Sea Hydrothermal Vent

question 36

Multiple Choice

Objections to the "stepping-stone" hypothesis, suggesting that deep-sea hydrothermal vent organisms are dispersed by taking advantage of whale falls (like stepping-stones) , include all of the following except

• A) the number of overlapping species found at multiple sites is small.
• B) most whales live and die in shallow waters.
• C) increasing numbers of vents found suggest that dispersal is not a problem.
• D) chemosynthetic organisms found at whale falls are not the same as at hydrothermal vents.

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Definitions:

Primary Capillary Networks

The initial network of capillaries where exchange of gases, nutrients, and wastes occurs between the blood and surrounding tissues.

Venous Sinuses

Large veins found in the brain and heart that collect deoxygenated blood to return it to the right atrium of the heart.

Capillary Wall

The thin, permeable layer of tissue that forms the boundary of capillaries, allowing for the exchange of gases, nutrients, and waste between blood and tissues.

Endothelium

The thin layer of cells that lines the interior surface of blood vessels and lymphatic vessels.