Final answer:
Toxins are poisonous substances naturally produced by animals, plants, and microbes, often serving as defense mechanisms. Venoms are a specific subset of toxins delivered through bites or stings by certain animals. Secondary metabolites, including antibiotics and alkaloids, contribute to the wide range of natural toxins.
Step-by-step explanation:
Toxins are poisonous substances of natural origin produced by an animal, a plant, or a microbe. These substances can cause death, injury, or harm to organisms when absorbed in sufficient quantities.
In the context of poison delivery methods, venoms are a specific type of toxin that is injected into another organism via bite or sting, a method exclusive to animals. The natural world has developed numerous ways to produce these toxic substances as defense mechanisms.
Poisonous plants, for example, produce chemicals to deter herbivores due to their inability to move away from predators. Similarly, animals may possess venom or other poisons to protect themselves or to catch prey.
Secondary metabolites are another form of natural toxins, not directly involved in the normal growth, development, or reproduction of organisms. These substances often function as defense chemicals and include a diverse group of compounds such as antibiotics, alkaloids, and toxic pigments, many of which are derived from primary metabolites.