In studying the toxicity of a substance, scientists use lab animals to measure how much effect a toxicant produces at different doses or how many animals are affected by different doses. the data is plotted to produce what is termed a

Answer;

-Dose-response curve

Explanation;

Dose response curve shows the relationship between an effect of a drug and the amount of drug given. It plots the drug dose (or concentration) against its effect. The relationship can be influenced by patient factors (e.g. age, disease) and by the presence of other drugs that compete for binding at the same receptor (e.g. receptor 'antagonists').

Dose-response curves can be used to plot the results of many kinds of experiments. The X axis plots concentration (or dose) of a drug or hormone. The Y axis plots response, which could be almost any measure of biological function.

the sphincter muscles at the end of the digestive tract is the anus.