A Level Biology Practice Exam

What is venom?

1. A type of harmless secretion found in various organisms

2. A harmful secretion injected into a victim by a venomous organism such as a snake or a spider

3. A liquid used by the body for digestion

4. A chemical released during the immune response

The correct answer is: A harmful secretion injected into a victim by a venomous organism such as a snake or a spider

Venom is specifically defined as a harmful secretion that is actively injected into another organism through specialized structures, such as fangs or stingers, by venomous creatures like snakes, spiders, and certain marine animals. This secretion often contains complex mixtures of proteins, enzymes, and toxins that can immobilize or kill prey, defend against predators, or deter competitors. The key aspect that distinguishes venom from other biological substances is its method of delivery, which involves direct injection into another organism. In contrast, the other options describe substances that do not meet the criteria of venom. For instance, a harmless secretion does not have damaging effects or is not delivered by a method that causes harm to others. A liquid used for digestion is related to processes like enzymatic breakdown of food, which does not involve injecting substances into other organisms. Similarly, a chemical released during the immune response pertains to the body's defense mechanisms against pathogens and does not involve a targeted injection mechanism characteristic of venom.