unit13

A farmer needs to kill more than half of the insect crop pests to ensure a profitable harvest. Based on the graph, what is the minimum concentration of pesticide CC that the farmer must use to make a profit?

1500 3

Based upon the data, what is the best description of this relationship?

As the concentration of anastrozole increases, the percent induction of breast cancer decreases.

An individual is exposed to the water in the stream from which the sample show in the graph was taken. If the individual was exposed to the highest dose of the bacteria, which of the following bacteria would have the lowest probability of causing illness if ingested?

C. jejuni

The United States Environmental Protection Agency has determined that all four pesticides could have negative health consequences to humans if applied at high concentrations and has set a maximum application concentration of 500g/cm3500g/cm3. Based on the data in the graph, which pesticide would be the most effective at that concentration?

D

An experiment was carried out to determine the lethal dose of ammonium sulfate on mung bean germination. True statements about the experimental design include which of the following? The control group has neither the seeds nor the ammonium sulfate. The independent variable is the concentration of the ammonium sulfate. The dependent variable is the number of seeds that failed to germinate. A

II and III only

If all four of the bacteria species shown in the graph are equally likely to contaminate agricultural products at a dose of 102 CFU102⁢ CFU, regulating which of the following species would have the greatest effect in reducing the likelihood of illness in humans? A

Salmonella

Some drinking water standards allow bacteria in water at dosages up to the 10% probability of illness. Which of the following statements is best supported by the data in the graph?

The newly discovered bacterium would have the lowest allowable dosage to meet the drinking water standards.

Students conducted an experiment to calculate the LD50LD50 of Chemical XX on seedlings. They grew separate groups of seedlings in a range of doses of Chemical XX. After several days they calculated the percent mortality at each dose and graphed the results. Which of the graphs correctly shows how to determine the LD50LD50 of Chemical XX on the seedlings?

a

The risk that many cancer-causing chemicals pose to humans can be estimated using laboratory tests on rats. A significant scientific limitation of such tests is that

animal models may not reflect human responses

Toxicologists say, "the dose makes the poison," meaning that most substances are harmful in high enough concentrations. The data for anastrozole

does not support this concept because as concentration increases, response decreases

A laboratory study using rats showed a steady increase in physical effects as the concentration of a toxic substance in their food was increased. This suggests that

the dose-response relationship is linear