What organ systems are present in Cnidaria?

Answer 1

Cnidarians are radically symmetrical, diploblastic animals. They have a gut cavity with a single opening; food goes in and waste material goes out through this same opening. This opening(mouth) is surrounded by a ring of tentacles.

Cnidarians are carnivores, and they have special stinging cells called nematocysts in the epidermis of their tentacles. Each nematocysts contains a coiled tubular structure, which often has barbs on it. A protein toxin may be contained in the tube, which may paralyses the prey.

Cnidarians have a very simple nervous system, in which the neurones are arranged in an irregular network throughout the body, called a nerve net. There is no "brain". They can move using muscle cells in the epidermis.

Cnidarians do not have a transport system. Gas exchange takes place by diffusion through the body surface, and the gases move by diffusion to and from the body cells.

Answer 2

1. Within the mesoglea we find a nerve net. These organisms do not contain a brain. .
2. They contain a central cavity called the Gastrovascular cavity. Digestion takes place here and the contents are absorbed by the endodermal cells. The undigested food is expelled through its mouth. This is considered a two way digestive process.
3. They reproduce by budding and regeneration. They also reproduce sexually. They contain both male and female reproductive structures in the same body. They are neither male or female, they are called hermaphroditic.