In dose-response curve of chemical substances, there exists a dose below which none of the animal is affected, which is called as:

Correct option is B

Introduction:

• A Threshold Dose is the dose below which no adverse effects are observed. In a dose-response relationship, this is the point at which the biological response starts to manifest.
• Below the threshold dose, the body's natural defenses can manage the exposure, and no observable harm occurs.

Information Booster:

• Absorbed Dose: The quantity of a substance that actually enters the body and reaches the target tissue.
• Acceptable Daily Intake (ADI): The maximum amount of a substance that can be ingested daily over a lifetime without appreciable health risk.
• Toxicity Reference Dose (RfD): An estimate of a daily exposure to a human population that is likely to be without risk of harmful effects during a lifetime.
• Critical in determining safe levels of exposure.
• Commonly used in setting safety standards for chemicals and drugs.
• Absorbed Dose: Used in toxicology to measure the amount of chemical that enters the body.
• Expressed in units like mg/kg of body weight.
• Acceptable Daily Intake (ADI):
• Typically used for food additives and contaminants. Expressed in mg/kg body weight/day.
• Toxicity Reference Dose (RfD): Developed by agencies like the EPA.
• Includes safety margins to protect sensitive populations.

Additional Knowledge:

• Dose-Response Relationship: Represents the relationship between the dose of a substance and the magnitude of the biological response.
• NOAEL (No Observed Adverse Effect Level): The highest dose at which no adverse effects are seen.
• LOAEL (Lowest Observed Adverse Effect Level): The lowest dose at which adverse effects are observed.
• LD50 (Lethal Dose 50%): The dose that kills 50% of the test population.