Answer:
1.Snakes use their venom cautiously, injecting amounts sufficient to disable prey or to defend against predators. Snake venom works by breaking down cells and tissues, which can lead to paralysis, internal bleeding, and death for the snake bite victim.
2.Snake venom and other toxins' strength is measured using the LD50 (lethal dose 50%) test. ... The amount of test substance that kills half the animals gives the LD50 figure. LD50 figures are used, in theory, to indicate the standard toxicity value for each chemical.