Without Genetic Variation, Evolution Cannot Occur

question 69

Multiple Choice

Without genetic variation, evolution cannot occur. Sexual reproduction leads to increased genetic variation, but male bdelloid rotifers have never been observed. Which of the following are correct statements with regard to evolution in bdelloid rotifers?

• A) As we learn more about bdelloid rotifers, we find males in more and more species.
• B) Bdelloid rotifers gain genetic variation by absorbing DNA from the external environment.
• C) Protists infect bdelloids and bring DNA from other rotifers with them.
• D) Bdelloid rotifers have lost the ability to reproduce sexually only recently.

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Definitions:

Marginal Revenue Product (MRP)

The change in a firm’s total revenue when it employs 1 additional unit of a resource (the quantity of all other resources employed remaining constant); equal to the change in total revenue divided by the change in the quantity of the resource employed.

Land

In addition to the part of the earth’s surface not covered by water, this term refers to any and all natural resources (“free gifts of nature”) that are used to produce goods and services. Thus, it includes the oceans, sunshine, coal deposits, forests, the electromagnetic spectrum, and fisheries. Note that land is one of the four economic resources.

Demand Curve

A curve that illustrates the demand for a product by showing how each possible price (on the vertical axis) is associated with a specific quantity demanded (on the horizontal axis).

Economic Rent

The price paid for the use of land and other natural resources that are in fixed (perfectly inelastic) supply.