CPA Pesticide Toxicology and Mode of Action

Question 1

What term describes the dose of a pesticide required to kill 50% of a test animal population under specified conditions?

Accepted Answer

LD50

Answer

LC50

Answer

ED50

Answer

TD50

Question 2

Which pesticide class inhibits acetylcholinesterase, preventing the breakdown of acetylcholine and causing continuous nerve stimulation?

Accepted Answer

Organophosphates

Answer

Pyrethroids

Answer

Neonicotinoids

Answer

Strobilurins

Question 3

What is the primary mode of action of pyrethroid insecticides such as permethrin and cypermethrin?

Accepted Answer

Block sodium channel inactivation

Answer

Inhibit mitochondrial electron transport

Answer

Inhibit acetylcholinesterase

Answer

Disrupt chitin synthesis

Question 4

Which type of toxicity results from a single or short-term exposure to a high dose of a pesticide?

Accepted Answer

Acute toxicity

Answer

Chronic toxicity

Answer

Subchronic toxicity

Answer

Cumulative toxicity

Question 5

A pesticide has an oral LD50 of 5 mg/kg body weight. How would this pesticide be classified under EPA toxicity categories?

Accepted Answer

Highly toxic (Category I)

Answer

Slightly toxic (Category III)

Answer

Moderately toxic (Category II)

Answer

Practically non-toxic (Category IV)

Question 6

For most pesticide applicators during routine fieldwork, which route of pesticide exposure is generally considered the most significant?

Accepted Answer

Dermal contact

Answer

Oral ingestion

Answer

Inhalation

Answer

Ocular absorption

Question 7

What term describes the potential of a pesticide to cause cancer in exposed organisms?

Accepted Answer

Carcinogenicity

Answer

Mutagenicity

Answer

Teratogenicity

Answer

Neurotoxicity