Robert Paine Was the First Biologist to Use the Term

question 27

Multiple Choice

Robert Paine was the first biologist to use the term keystone species in the 1960s. He was studying food webs in the rocky, intertidal pools in the Pacific Northwest. At one of his study sites, the dominant organisms in the tidal pools were mussels, barnacles, whelks, and a species of starfish known as Pisaster ochraceus . To examine the relationship between these species, Paine set up an experiment. In one area, he removed all the starfish from the tidal pools, and in an adjacent area, he left the tidal pools as he found them. Prior to removing the starfish, he sampled all the organisms in each pool. After two months, he repeated this sampling. A summary of his results is illustrated in the graph below.

After two months, Paine repeated the sampling. In this experiment, he is sampling the __________.

• A) biodiversity
• B) first trophic level
• C) energy pyramids
• D) ecological niche

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Definitions:

Ping Ponging

The process in which legislative bills are sent back and forth between the two houses of a legislature for approval or amendment.

Divided Congress

A situation in which one party controls the U.S. House of Representatives and another party controls the U.S. Senate.

Conference Committees

are temporary committees formed to reconcile differences between the House and Senate versions of a bill before it is sent to the president for approval.

Legislation Compromise

Legislation compromise refers to the process of finding a middle ground in legislative negotiations, where conflicting parties come to a mutual agreement to pass a bill.