An Invasive Snail Is Accidentally Introduced into a River

question 57

Multiple Choice

An invasive snail is accidentally introduced into a river.It carries a pathogen to which it is adapted; however, the pathogen is a generalist that can infect various other mollusk species in the river and downstream.What is the most likely effect the introduced pathogen will have on the mollusk diversity of the river?

• A) It will remain in the invasive snail and will not affect the rest of the ecosystem.
• B) It will decrease mollusk biodiversity as it spreads into local species that are not adapted.
• C) It will enter other mollusks, but they will likely adapt readily to its presence.
• D) It will try to enter other mollusk species but be unable to become established.
• E) It will enter other mollusks but can be eradicated by removal of the invasive snail.

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Definitions:

Income Elasticity

A measure of how much the demand for a product or service changes relative to a change in consumers' income.

Total Revenue

The total income a firm receives from the sale of its goods or services before any costs or expenses are subtracted.

Least Elastic

Refers to the degree of responsiveness or sensitivity of demand or supply to changes in prices, with the least elastic being the least responsive.

Straight-Line Demand

Straight-Line Demand refers to a demand curve that shows a constant rate of change in the quantity demanded as price changes.