Robert Paine Was the First Biologist to Use the Term

question 7

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.

As mussels and barnacles feed, how much of the energy that they take in from food is available to the whelks that eat them?

• A) 10 percent
• B) 90 percent
• C) 1000 calories
• D) 10,000 calories

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Definitions:

Hormonal Differences

Variations in the types, levels, and effects of hormones in the body that can influence a wide range of physiological activities including development, mood, metabolism, and behavior.

Depression

A common and serious mood disorder characterized by persistent feelings of sadness, hopelessness, and loss of interest, often accompanied by physical symptoms.

Addiction

Addiction is a psychological and physical inability to stop consuming a chemical, drug, activity, or substance, even though it is causing psychological and physical harm.

Brain Areas

Specific regions within the brain specialized for distinct cognitive or physiological functions.