Which of the following best describes metamorphosis in fleas?

Metamorphosis in fleas is classified as complete metamorphosis, which involves four distinct life stages: egg, larva, pupa, and adult. This process allows for significant changes in form and function as the organism develops from one stage to another. The larval stage is entirely different from the adult flea, showcasing the dramatic changes that occur during development.

In contrast, gradual metamorphosis involves life stages that are more similar to one another, which does not apply to fleas. There is a significant transformation from the larval stage to the adult stage in complete metamorphosis, indicating that the organism undergoes a more complex development process. Thus, the characterization of metamorphosis in fleas as complete is accurate and aligns with the biological understanding of their life cycle.