Explain how the structural features of worms are interconnected with the way of life and habitat conditions.

Worms can exist both freely in their environment, and be parasites of other animals and plants. Free-living worms are characterized by the presence of an elongated body shape, more pronounced sensory organs, the presence of devices for movement (especially in annelids (bristles). Parasitic worms have their own specific adaptations. For holding in or on the body of the host organism, they have special suction cups and hooks The body is covered with a protective layer that prevents them from being exposed to gastric acids.