Final answer:
Constitutive defenses are the innate defenses that a plant or organism possesses at all times, while inducible defenses are defenses that are activated in response to an attack or threat. Examples of constitutive defenses include thorns or spines on plants and the production of lignin. Examples of inducible defenses include the production of defensive proteins or chemicals in response to pathogens or herbivores.
Step-by-step explanation:
Constitutive defenses are the innate defenses that a plant or organism possesses at all times, while inducible defenses are defenses that are activated in response to an attack or threat. A well-known example of a constitutive defense in plants is the presence of thorns or spines on the surface of stems or leaves, which act as physical barriers to deter herbivores. Another example is the production of lignin, a complex polymer that strengthens the cell walls of plants, making them more resistant to microbial attack.
Inducible defenses, on the other hand, are only activated when a plant is under attack or threatened. An example is the production of defensive proteins or chemicals in response to the presence of pathogens or herbivores. These proteins may interfere with the growth or reproduction of the attackers, or attract predators or parasitoids that can control the population of the attackers.