Question

a research group has discovered that damselflies, a type of dragonfly, are being infected by a particular type of aquatic protozoan. both young and adult damselflies are not directly infected by the protozoan but contract the infection from the prey they eat. the graph shows the percentage of adult damselflies infected by protozoans during the summer and early fall.
occurrence of protozoan infection
in adult damselflies
bar graph with x - axis as date of sample (8/1, 8/16, 9/1, 9/16, 10/1, 10/16) and y - axis as percentage infected. legend: embarked ponds (light bars), creek - fed ponds (dark bars)
which of the following conclusions is supported by the graph?
a. infection in embanked ponds increased during the sampling period.
b. protozoans were more common in creek - fed ponds than embanked ponds.
c. protozoans reproduce more quickly in embanked ponds than creek - fed ponds.
d. infection in creed - fed ponds remained constant throughout the sampling period

1. what is the question asking?

what is the correct answer?
why are the other answers incorrect?

Explanation:

The question asks which conclusion is supported by the bar graph showing infection rates of adult damselflies in embanked vs. creek-fed ponds over time.

• Option A: The white bars (embanked ponds) show increasing infection rates from ~10% (8/1) to ~70% (10/16), so infection increased during sampling.
• Option B: Not supported—embanked ponds have higher rates than creek-fed in later samples.
• Option C: The graph does not measure reproduction rate, only infection prevalence.
• Option D: Creek-fed rates (black bars) fluctuate (38% → 35% → 38%), not constant.

Only Option A aligns with the graph’s data.

Answer:

A. Infection in embanked ponds increased during the sampling period.