When a person needs a gradual increase in the amount of a psychoactive drug to produce the desired effect, has occurred.

drug tollerance

When a person needs a gradual increase in the amount of a psychoactive drug to produce the desired effect, drug tollerance has occurred.

a

explanation:

many plants naturally reproduce this way, but it can also be induced artificially. horticulturalists have developed asexual propagation techniques that use vegetative plant parts to replicate plants. success rates and difficulty of propagation vary greatly. monocotyledons typically lack a vascular cambium and therefore are harder to propagate.