Gonad Experiment Essay

Gonad Experiment (from the first page’s diagram)
Hypothesis: Exposure to atrazine during larval development causes abnormalities in the reproductive tissues of male frogs. (taken from diagram)
Independent Variable: Atrazine exposure levels in parts per billion Levels: 0,0,1, and 25 ppb
Dependent Variable: percentage of male frogs with gonadal abnormalities
Control Group: Male African Clawed Frogs exposed to 0.0 ppb of atrazine
Constants: same type of tadpoles, same tank environment (excluding atrazine) (ie. Temperature, light exposure etc.), same amount of tadpoles in each tank
Vocal Structures Experiment
Hypothesis: Exposure to greater atrazine levels will cause the cross sectional area of the laryngeal muscle in African Clawed Frogs to decrease in size.

An endocrine disruptor can block hormones and disrupt bodily functions. Some effects of disruption can include overproduction or underproduction of hormones, and blocking some effects of hormones from receptors.

Some questions raised are: Did Dr. Hayes record inaccurate data due to his methodology and misrepresentations of other citations? Did Dr. Hayes’ data even support his conclusions? If Dr. Hayes’ believes his research is correct, why won’t he release his raw data for independent review?

There was no difference in the effect of atrazine on both genders. For both genders, once the level was past 1 ppb, a steady decrease of size is noted, but when less than 1 ppb, a minimal increase is seen. In both trials, the data had the same pattern of size increase and decrease with the levels of atrazine despite the different levels, thus the experiment was repeatable.

The effect of an exposure that is less than 1 ppb typically resulted in a small increase in size, but once the atrazine level was 1 ppb or greater, there was a steady decrease in the muscle’s size. Therefore, the effect of atrazine of muscle size is not