CPA Pesticide Toxicology and Mode of Action 3

Question 1

Diamide insecticides such as chlorantraniliprole control insects through which mode of action?

Accepted Answer

Ryanodine receptor activation causing uncontrolled muscle contraction

Answer

Diamides activate ryanodine receptors, triggering uncontrolled release of calcium from muscle cells, causing paralysis and death in insects.

Question 2

Which signal word appears on a pesticide label when the product falls into EPA Toxicity Category II (moderately toxic)?

Accepted Answer

WARNING

Answer

Category II products (oral LD50 of 50–500 mg/kg) require the signal word WARNING on the front panel of the label.

Question 3

Glyphosate herbicide kills plants by inhibiting which enzyme critical to amino acid biosynthesis?

Accepted Answer

EPSPS (5-enolpyruvylshikimate-3-phosphate synthase)

Answer

Glyphosate inhibits EPSPS in the shikimate pathway, blocking synthesis of aromatic amino acids essential for plant growth and survival.

Question 4

Chronic pesticide toxicity refers to adverse health effects that result from:

Accepted Answer

Repeated or prolonged exposures over an extended period of time

Answer

Chronic toxicity develops from repeated low-level exposures over months or years and may include cancer, reproductive effects, or organ damage.

Question 5

Hepatotoxic pesticides primarily target which organ in exposed individuals?

Accepted Answer

Liver

Answer

Hepatotoxic pesticides damage the liver (hepato = liver), which is the primary organ responsible for metabolizing and detoxifying pesticide compounds.

(CPA) Certified Pesticide Applicator Practice Test

(CPA) Certified Pesticide Applicator Practice Test

CPA Pesticide Toxicology and Mode of Action 3