Question

both are experimental groups, but only test group 1 shows the effect of direction of light.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. which of the following conclusions is supported by the graph? occurrence of protozoan infection in adult damselflies 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 creek - fed ponds remained constant throughout the sampling period.

Explanation:

1. Analyze option a: Looking at the light - colored bars (embanked ponds) on the graph, the percentage of infected adult damselflies increases from 8/1 to 10/16. So, this option is supported.
2. Analyze option b: The graph only shows the percentage of infected damselflies, not the overall prevalence of protozoans in the ponds. So, this option is not supported.
3. Analyze option c: The graph does not provide any information about the reproduction rate of protozoans. So, this option is not supported.
4. Analyze option d: The percentage of infected damselflies in creek - fed ponds (dark - colored bars) changes over the sampling period, so it is not constant. So, this option is not supported.

Answer:

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