Question

in an ecosystem, lemmings make up a major portion of the diet of snowy owls. a viral infection resulted in a decli which graph best represents the expected changes in the population of the snowy owls and the lemmings?

Explanation:

To solve this, we analyze the predator - prey relationship between snowy owls (predator) and lemmings (prey):

Step 1: Analyze the effect on lemmings

A viral infection causes a decline in the lemming population. So the lemming population curve should show a downward trend over time.

Step 2: Analyze the effect on snowy owls

Since lemmings are a major part of the snowy owls' diet, as the lemming population (prey) declines, the snowy owl population (predator) will also decline because of the lack of food. However, the decline in the snowy owl population may have a lag or follow the decline in the lemming population.

Step 3: Evaluate the graphs

• In a typical predator - prey graph, when the prey population (lemmings) decreases, the predator population (snowy owls) also decreases. The first graph (with the key showing lemming and snowy owl populations) has the lemming population (the lighter line) and the snowy owl population (the darker line) both showing a general downward trend, with the lemming population perhaps declining first and then the snowy owl population following. The second graph (the one with only one curve shown in the lower part) does not seem to represent the two - population (predator - prey) relationship properly as it only shows a single - like decline without the distinction between the two populations.

So the graph that best represents the expected changes is the first one (the one with the key for lemming and snowy owl populations, where both populations show a downward trend with the lemming population potentially declining first and the snowy owl population following).

Answer:

The graph with the key (Lemming Population - lighter line, Snowy Owl Population - darker line) showing both populations having a general downward trend over time (the upper graph with the two - line plot and the key).