If a Ray-Finned Fish Is to Both Hover (Remain Stationary)in

question 52

Multiple Choice

If a ray-finned fish is to both hover (remain stationary) in the water column and ventilate its gills effectively, then what other structure besides its swim bladder will it use?

• A) its heart
• B) its pectoral fins
• C) its lateral line system
• D) its caudal (tail) fin
• E) its opercula

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Definitions:

Perfect Competition

A market structure characterized by a large number of small firms, a homogenous product, perfect information, and easy entry and exit, leading to firms being price takers.

Marginal Decision Rule

A principle stating that an action should be taken if, and only if, the marginal benefit of the action exceeds its marginal cost.

Marginal Revenue

The extra revenue gained from the sale of an additional unit of a product or service.

Perfect Competition

A market structure characterized by many buyers and sellers, freedom of entry and exit, and a homogeneous product.