Source: Revised GRE PDF 2nd Ed. Section 3; #13 (p. 55)

1

According to the passage, which of the following

Geese can often be seen grazing in coastal salt marshes. Unfortunately, their intense grazing removes the grassy covering, exposing marsh sediment; this increases evaporation, which in turn increases salt concentration in marsh sediments. Because of this increased concentration, regrowth of plants is minimal, leading to increased erosion, which leads to a decrease in the fertile topsoil, leading to even less regrowth. In time, the salt marsh becomes a mudflat. This process challenges one of the most widely held beliefs about the dynamics of salt-marsh ecosystems: supposedly, consumers such as geese do not play a large role in controlling the productivity of marsh systems. Rather, the standard view claims, marshes are controlled by bottom-up factors, such as nutrients and physical factors. According to the passage, which of the following is a widely held belief about geese? They are not often seen grazing in coastal salt marshes., They are not the primary consumers in salt-marsh ecosystems., They play only a minor role in the productivity of salt-marsh ecosystems., They are the primary determinants of which resources will thrive in coastal salt marshes., They control the productivity of salt-marsh ecosystems through a bottom-up process.

2 Explanations

1

Kalina Gajda

Why is the answer not B?

Apr 3, 2019 • Comment

Adam Lyons, Magoosh Tutor

Hey Kalina,
The passage only lists geese as consumers, while not indicating at all if they are the primary consumers or not.
On the contrary, the passage states that Geese's grazing is an important cause of decline in salt marshes. So if anything, we would lean toward Geese being one of the primary consumers.

Apr 5, 2019 • Reply

1

Gravatar Chris Lele, Magoosh Tutor

Sep 21, 2012 • Comment

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