Robert Paine Was the First Biologist to Use the Term

question 41

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.

The control group in Paine's study is __________.

• A) the tidal pools from which starfish were removed
• B) the tidal pools from which starfish were not removed
• C) all tidal pools included in the study

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Definitions:

Balance Sheet

A financial document showing what a company owns, owes, and the equity of its shareholders at a fixed point in time.

Trial Balance

An accounting table that aggregates all ledger balances into debit and credit columns, ensuring both totals are identical.

Income Statement

A financial statement that shows a company's revenues and expenses over a specific period, leading to its net income or loss.

Retained Earnings

The cumulative earnings of a company that have not been distributed to shareholders as dividends, reinvested back into the company.