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What are the three body layers in cnidarians?
Similar to sponges, cnidarians are diploblasts, meaning that they develop from two basic germ (cell) layers: an ectoderm, or outer layer, and an endoderm, or inner layer. Between the ectoderm, which contains the cnidocysts, and the endoderm there is a non-cellular substance called the mesoglea.
What are the layers of a cnidarian?
Cnidarians consist of two cell layers: an outer ectoderm and an inner endoderm (the gastrodermis) that lines the coelenteron.
What is the outermost layer of a cnidarian?
All cnidarians have two tissue layers. The outer layer is called the epidermis, whereas the inner layer is called the gastrodermis and lines the digestive cavity. Between these two layers is a non-living, jelly-like mesoglea.
What is the skeleton of cnidaria?
Cnidarians have a hydrostatic skeleton. The contractile fibers act against the fluid-filled gastrovascular cavity. The movements are like a balloon; the animal can be short and thick or long and thin. Cnidarians have a saclike gut and extracellular digestion.
What is the skeleton of a cnidarian?
How many layers does a cnidarian body have?
Cnidarian bodies have two or sometimes three layers. A gastrovascular cavity (coelenteron) has a single exterior opening that serves as both mouth and anus. Often tentacles surround the opening. Some cells are organized into two simple nerve nets, one epidermal and the other gastrodermal, that help coordinate muscular and sensory functions.
Do cnidarians have a simple digestive system?
Cnidarians may exist in the polyp (left) or medusa (right) form. The body of a cnidarian consists of two cell layers, ectoderm and endoderm. The cellssurround a digestive cavity called the coelenteron (see Figure below ). Cnidarians have a simple digestive system.
Which of the following cnidarians have radial symmetry?
All cnidarians have radial symmetrical. There are two major body forms among the Cnidaria – the polyp and the medusa. Sea anemones and corals have the polyp form, while jellyfish are typical medusae.
What is the difference between Cnidaria and sea anemones?
Some colonial sea anemones stiffen the mesoglea with sediment particles. Cnidaria are diploblastic animals; in other words, they have two main cell layers, while more complex animals are triploblasts having three main layers.