Question

Why are inducible defences advantageous?
A. They are always present- thus, an individual is always able to defend itself.
B. They make it impossible for a consumer to launch surprise attacks.
C. They result from a co-evolutionary arms race.
D. They make efficient use of resources, because they are produced only when needed.

Answer 1

Hint: Inducible defenses are reactions that are brought on by a previous interaction with a customer or rival and offer some level of protection from attacks in the future. Plants can be phenotypically flexible thanks to inducible defenses.

Complete step by step solution:
The ability of plants to defend themselves indirectly by luring carnivorous adversaries of herbivorous arthropods can vary depending on the species and genotype of the plants, the species or instar of the herbivores, and possibly other environmental factors.
In situations where such biological compounds are not yet required, induced defenses are favorable since they lighten the metabolic burden on the plant. When a herbivore or predator is not present, inducible defenses enable an organism to save money by only allocating resources to defense when they are actually needed.
Numerous defense systems have evolved by plants to fend off insect herbivory. These defenses can be broadly divided into two groups: (1) constitutive, permanent defenses, and (2) induced, transient defenses. Both types are accomplished using comparable techniques, however constitutive protections exist prior to a herbivore attack, whereas induced defenses are only active during attacks. In addition to intrinsic defenses, one crucial tactic for plant survival and persistence is the instigation of particular defense responses to herbivory.
So, option (D) is correct.

Note:
Both types are accomplished using comparable techniques, however constitutive protections exist prior to a herbivore attack, whereas induced defenses are only active during attacks.