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Genetics and Survival


Scientists discover two hypothetical species of freshwater fish living in small pools that are connected by streams during the rainy season but isolated from each other during the dry season.

Species A reproduces asexually. Species B reproduces sexually. Both species are susceptible to a parasitic worm that causes a condition called "Black Spot Disease."

Scientists identified a pool in which both species of fish lived but in which no parasite existed. After taking an initial survey of both populations, scientists then intentionally infected the pool with the parasite that causes Black Spot Disease.

Three years later, they returned and resampled the populations of the two species of fish in the pool. Their results are represented in the graph below.

Created for Albert.io. Copyright 2016. All rights reserved.

Which of the following statements is BEST supported by the results of this experiment?


Species B can reproduce faster and outcompete Species A for food and other resources.


Species B is a predator of Species A except when Species A is infected by a parasite.


Species A is partially protected from the effects of the parasite by the presence of Species B.


Species A is more susceptible to the effects of the parasite due to its lack of genetic diversity.