apes seciton 1

A pesticide was applied to a population of roaches, and it was determined that the LD50 was 55mgkg. If the average mass of a roach was 0.02kg, which of the following approaches will determine the dose in mg per roach?

55mg/1kg x 0.02kg

Based on the LD50 values, which of the following best describes the toxicity level of the household substances shown in the table?

Antifreeze is more toxic than aspirin.

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

Which of the following best describes why ddt is classified as a persistent organic pollutant? Responses

DDT is very stable, and as much as 50% of the original concentration can remain in the soil 15 years after the initial application.

For a certain insecticide, the LD-50 dosage level for rats is determined to be 250 milligrams per kilograms of body mass. On the basis of this information, which of the following is the best prediction regarding the consequences of receiving this dosage of the insecticide?

Five hundred out of every one thousand rats would die.

Some toxic compounds are ingested and retained in the tissues. These pollutants pose special risks to humans and other organisms high on the food chain because of which process?

Holding prey

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?

II and III only

Which of the following is the most likely consequence of runoff transporting chemicals that are endocrine disruptors to a pond?

Increased frequency of birth defects in fish populations in the pond

Which of the following best explains why top predators can have up to 60 times as much of persistent organic pollutant (POP) as their prey and up to 600 times as much of the pollutant as producers?

POPS accumulate in the body fat of living organisms. POPs increase in concentration as they move up the food chain.

The graph below depicts the dose response curves for three common bacteria and a newly discovered bacterium found in streams near certain agricultural properties.

Salmonella spp

Many synthetic chemicals, such as PCBs, act as estrogen mimics. In an ecosystem, these persistent chemicals would have the greatest effect on which of the following? Responses

Secondary consumers

Scientists are interested in determining if selenium, from a nearby mine, magnifies in the tissues of fish living in a lake. Which of the following best describes a testable hypothesis for the study?

Selenium will be at a higher concentration in fish tissue than in the tissue of fish prey.

Which of the following is the most likely explanation of how herbicides affect amphibians?

The herbicides act as endocrine disruptors.

Endocrine disruptors directly affect which of the following in an organism?

horomones