Question

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 weakens the students conclusion? choose 1 answer the spider population count was the same in both enclosures on day 1 the spider population count also substantially declined by day 30 in the enclosure without lizards the largest decline in spider population count in the enclosure with lizards occurred from day 1 to day 10 the spider population count on day 20 was lower in the enclosure with lizards than in the enclosure without lizards

Explanation:

Step1: Analyze the conclusion

The student concludes spider - population reduction in lizard enclosure is due to lizards.

Step2: Evaluate option A

Option A about equal counts on day 1 is not relevant to the cause - effect conclusion.

Step3: Evaluate option B

If spiders declined in non - lizard enclosure too, it challenges the idea that decline in lizard enclosure is only due to lizards.

Step4: Evaluate option C

The time of largest decline in lizard enclosure doesn't address other factors.

Step5: Evaluate option D

Comparing day 20 counts doesn't help determine if lizards are the sole cause of decline by day 30.

Answer:

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