Final answer:
The LD50 is a measure of the toxicity of a substance, given as the dose that kills 50% of the test animals, usually expressed as milligrams per kilogram of body weight. True, the LD50 is determined by dividing the milligram dose of poison by the kilograms of the target pest's body weight.
Step-by-step explanation:
The LD50 (Lethal Dose, 50%) is a scientific measure used to indicate the toxicity of a substance. It represents the amount of a chemical that, when administered to a group of test animals, is expected to cause death in 50% of the animals. The LD50 is usually expressed in milligrams of the substance per kilogram of body weight of the test animal (mg/kg). This means that the correct calculation involves dividing the milligram dose of the substance by the kilograms of the animal's body weight to arrive at the LD50.
It is important to note that the lower the LD50 value, the more toxic the chemical is. For example, a substance with an LD50 of 5 mg/kg is more toxic than one with an LD50 of 200 mg/kg because it takes a much smaller dose to cause death in 50% of the test animals. Additionally, LD50 values can vary significantly between species, and the method of administration (oral, injection, skin) also affects the LD50.