Question 1

Which of the following best describes the process of biomagnification as illustrated in the DDT concentration diagram?

Accepted Answer

The concentration of DDT increases at higher trophic levels due to accumulation in organisms.

Question 2

Which of the following is an example of a chemical hazard as defined in environmental health?

Accepted Answer

Pesticides

Question 3

A scientist is studying the effects of a new pesticide on frogs. She exposes groups of frogs to increasing doses and records the percentage that die at each dose. What is the term for the dose at which 50% of the frogs die?

Accepted Answer

LD50

Question 4

Which of the following indoor hazards is a colorless, odorless, radioactive gas that seeps from the ground and can cause lung cancer?

Accepted Answer

Radon

Question 5

Which type of toxin specifically interferes with the nervous system and can cause symptoms such as tremors, paralysis, or convulsions?

Accepted Answer

Neurotoxin

Question 6

A dose-response curve with a threshold (as shown in the images) indicates what about the toxin's effect?

Accepted Answer

There is a minimum dose below which no effect is observed.

Question 7

Which of the following best explains why top predators, such as ospreys, have the highest concentrations of DDT in their bodies?

Accepted Answer

They eat large amounts of prey that have accumulated DDT.

Question 8

Which of the following is a synergistic effect in toxicology?

Accepted Answer

Two toxins together have an effect greater than the sum of their individual effects.

Question 9

Which of the following is NOT a method used to study the effects of toxins on organisms?

Accepted Answer

Randomized controlled trials on humans with lethal doses

Question 10

Which of the following best describes bioaccumulation?

Accepted Answer

The buildup of toxins within an individual organism over time.

Question 11

Which of the following is a likely consequence if a toxin harms decomposers in an ecosystem?

Accepted Answer

Decreased nutrient cycling

Question 12

Which of the following is an example of an endocrine disruptor?

Accepted Answer

BPA (Bisphenol A)

Question 13

A nonlinear inverted dose-response curve (as shown in the images) suggests what about the toxin's effect?

Accepted Answer

The effect is highest at intermediate doses and decreases at higher doses.

Question 14

Which of the following is a cultural hazard?

Accepted Answer

Living near a factory with poor air quality

Question 15

Which of the following statements about synthetic chemicals is TRUE?

Accepted Answer

Not all synthetic chemicals are harmful.

Question 16

Which of the following best describes the role of epidemiological studies in environmental toxicology?

Accepted Answer

They track the fate of people who were exposed or not to a toxin over time.

Question 17

Which of the following is a likely effect of a pathway inhibitor toxin?

Accepted Answer

It blocks steps in biochemical processes.

Question 18

Which of the following is the most common cause of death by infectious disease worldwide, according to the provided data?

Accepted Answer

Respiratory infections

Question 19

If a chemical has an LD50 of 10 mg/kg, what does this mean?

Accepted Answer

10 mg/kg is the dose at which 50% of the population dies.

Question 20

Which of the following best explains why persistent toxins such as DDT are a concern for polar ecosystems?

Accepted Answer

They travel by air currents and accumulate in polar regions.

Environmental Toxicology: Toxins, Hazards, and Their Impacts on Ecosystems and Human Health

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