module57REVIEW

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In this module, we learned there are many types of chemicals that can potentially cause harmful effects in humans. Neurotoxins disrupt the nervous systems of animals, carcinogens cause cancer, teratogens cause abnormal development in embryos and fetuses, allergens cause abnormally high immune responses, and endocrine disruptors interfere with the normal functioning of hormones. For each of these types of chemicals, scientists can determine the concentrations of chemicals that will harm organisms using short-term LD50 to assess lethal effects and ED50 studies to assess sublethal effects. Scientists can also use chronic studies that examine long-term effects of chemical exposure including both retrospective and prospective studies. Once we understand how different concentrations of a chemical can affect an organism, we can determine the concentrations that an organism could experience by examining solubility, bioaccumulation, biomagnification, and the persistence of chemicals in the environment. In the next module, we will examine how scientists analyze the risk that chemicals or any other environmental hazard poses to humans and other species.

Module 57 AP® Review Questions

Question 1

1. Atrazine and DDT are examples of

  1. neurotoxins.

  2. carcinogens.

  3. teratogens.

  4. allergens.

  5. endocrine disruptors.

Question 2

2. Teratogens

  1. interfere with embryo and fetus development.

  2. disrupt the circulatory system.

  3. alter the function of hormones.

  4. suppress the immune system.

  5. cause inflammation and cell damage.

Question 3

3. If 1 mg/kg of mass of a pesticide is the LD50 for rats in an experiment, what would be considered the safe exposure for humans?

  1. 10 mg/kg

  2. 1 mg/kg

  3. 0.1 mg/kg

  4. 0.01 mg/kg

  5. 0.001 mg/kg

Question 4

4. Which is NOT a cause of high concentrations of DDT in fish-eating birds?

  1. Bioaccumulation

  2. Biomagnification

  3. Persistence

  4. Synergistic interactions

  5. Solubility

Question 5

5. A prospective study

  1. determines synergistic interactions of toxins.

  2. measures the effect of a particular event after it has occurred.

  3. monitors individuals who might be exposed to harmful chemicals in the future.

  4. determines the number of individuals who might be effected by a particular chemical.

  5. determines the lethal dose of a chemical or toxin.