Question

1. to investigate the effect of lizard predation on spider populations, a student in a biology class placed spiders in two enclosures, one with lizards and one without, and tracked the number of spiders in the enclosures for 30 days. the student concluded that the reduction in the spider population count in the enclosure with lizards by day 30 was entirely attributable to the presence of the lizards.

which choice best describes data from the graph that weaken the student’s conclusion?
a) the spider population count was the same in both enclosures on day 1.

b) the spider population count also substantially declined by day 30 in the enclosure without lizards.

c) the largest decline in spider population count in the enclosure with lizards occurred from day 1 to day 10.

d) the spider population count on day 30 was lower in the enclosure with lizards than in the enclosure without lizards.

Explanation:

The student concludes that lizards caused the spider population reduction. To weaken this, we need data showing another factor could be responsible. Option B shows the spider population also declined substantially in the enclosure without lizards, meaning the decline might not be solely due to lizards (other factors could be at play). Option A is a control (same start) and supports the experiment. Option C just describes the decline timing in the lizard enclosure, not weakening the conclusion. Option D supports the idea that lizards reduced the population, strengthening the conclusion.

Answer:

B) The spider population count also substantially declined by day 30 in the enclosure without lizards.