The Herbicide Atrazine Is a Known Endocrine Disruptor to the Development

Multiple Choice

The herbicide atrazine is a known endocrine disruptor to the development stages of several animal species, including fish, reptiles, and amphibians. Scientists interested in studying long-term effects of exposure to atrazine on mating behaviors compared an all-male population of sexually mature African clawed frogs (Xenopus laevis) exposed to atrazine (Atz) to a sexually mature population of African clawed frogs not exposed to atrazine (Con) . Amplexus is defined as the mating position of frogs.

-The role of the nontreated males in this experiment is to

A) increase the sample size.
B) act as controls.
C) show that not all matings are successful.
D) determine number of matings per frog.