LD50 measure: LD50 is the dose lethal to what proportion of the population?

LD50 measure: LD50 is the dose lethal to what proportion of the population?

• A. 0%
• B. 25%
• C. 50%
• D. 100%

Answer: (C)

LD50 is the dose that would kill half of the individuals in a defined population under specified conditions. It’s called the median lethal dose because it sits at the middle of the dose–response curve: about 50% die and 50% survive at that dose. The actual value depends on the species, the substance, the route of exposure, and other factors, and is usually expressed as milligrams of substance per kilogram of body weight. Other benchmarks exist (such as LD25 or LD90) for different death proportions, but LD50 specifically targets 50%.

LD50 is the dose that would kill half of the individuals in a defined population under specified conditions. It’s called the median lethal dose because it sits at the middle of the dose–response curve: about 50% die and 50% survive at that dose. The actual value depends on the species, the substance, the route of exposure, and other factors, and is usually expressed as milligrams of substance per kilogram of body weight. Other benchmarks exist (such as LD25 or LD90) for different death proportions, but LD50 specifically targets 50%.