Many roundworm species are free-living. They have a body cavity that is between the endoderm and mesoderm tissues. The endoderm germ layer is like an internal layer and the mesoderm germ layer is like a middle layer. The body cavity is known as a pseudocoelom, due to it only being relatively lined with the mesoderm tissue. Roundworms have a digestive tract that consists of two openings, which are a mouth and an anus. Roundworms need to depend on diffusion, or the natural spreading of particles from a high to a low concentration, for their circulation, excretion, and respiration, as they also have no circulatory system like the flatworms. In roundworms, the fluid and muscles that are contained in the pseudocoelom operate as a hydrostatic skeleton, or an exoskeleton that maintains its form due to the pressure of fluid inside the skeleton. Roundworms have two nerve cords that transmit impulses in the roundworm. Also, they are able to reproduce sexually by internal
Many roundworm species are free-living. They have a body cavity that is between the endoderm and mesoderm tissues. The endoderm germ layer is like an internal layer and the mesoderm germ layer is like a middle layer. The body cavity is known as a pseudocoelom, due to it only being relatively lined with the mesoderm tissue. Roundworms have a digestive tract that consists of two openings, which are a mouth and an anus. Roundworms need to depend on diffusion, or the natural spreading of particles from a high to a low concentration, for their circulation, excretion, and respiration, as they also have no circulatory system like the flatworms. In roundworms, the fluid and muscles that are contained in the pseudocoelom operate as a hydrostatic skeleton, or an exoskeleton that maintains its form due to the pressure of fluid inside the skeleton. Roundworms have two nerve cords that transmit impulses in the roundworm. Also, they are able to reproduce sexually by internal