The amount of toxin needed to poison an animal is often dependent on which of the following factors?

• A. The animal's fur color
• B. The animal's body mass
• C. The animal's habitat temperature
• D. The animal's eye size

Answer: (B)

Verified step by step guidance

1. Understand the concept of toxin dosage: The amount of toxin required to poison an animal is typically proportional to its body mass. Larger animals generally require a higher dose of toxin compared to smaller animals.
2. Eliminate irrelevant factors: Fur color, eye size, and habitat temperature are not directly related to the physiological process of toxin absorption or the animal's susceptibility to poisoning.
3. Focus on body mass: Body mass is a critical factor because it determines the volume of distribution for the toxin within the animal's body. Larger animals have more tissue and fluid to dilute the toxin, requiring a higher dose to achieve the same effect.
4. Consider the principle of dose per unit mass: Toxicologists often calculate the effective dose of a toxin using the formula: $D=d\times m$, where $D$ is the total dose, $d$ is the dose per unit mass, and $m$ is the animal's body mass.
5. Conclude that body mass is the correct factor: Based on the biological principle of toxin distribution and dosage calculation, the animal's body mass is the most relevant factor influencing the amount of toxin needed to poison it.