How are sponges and cnidarians alike and different?
These organisms show a simple organization. Sponges have multiple cell types that are geared toward executing various metabolic functions. Cnidarians have outer and inner tissue layers sandwiching a noncellular mesoglea. Cnidarians possess a well-formed digestive system and carry out extracellular digestion.
What is the main difference between the Cnidaria and the platyhelminthes phylum?
Cnidarians are diploblastic, whereas Platyhelminthes are triploblastic. Platyhelminthes possess bilaterally symmetrical, soft, worm-like elongated bodies, whereas cnidarian possess radially symmetrical, soft, medusa-like or polyp-like body forms. Cephalization is present in Platyhelminthes, but not in cnidarians.
What is the difference between cnidarians and flatworms?
Flatworms are more complex than cnidarians. Cnidarians have two layers of cells, the ectoderm and the endoderm; flatworms have a middle layer called the mesoderm between the other two layers (Fig. 3.16). The cells of the ectoderm and endoderm are also more organized than similar cells of cnidarians.
What are 3 characteristics that all cnidarians have in common?
What are three characteristics that all cnidarian have in common? Cnidarians have an epidermis, gastrodermis, mesoglea, gastrovascular activity and tentacles. Also, they have cnidocytes and a nervous system composed of diffuse web of interconnected nerve cells called a nerve net.
What is the difference between Platyhelminthes and Nematoda?
The main difference between Platyhelminthes and Nematoda is that Platyhelminthes consists of flatworms with a thin, dorso-ventrally flattened body whereas Nematoda consists of a cylindrical body, which is tapered to fine ends at each end. Tapeworms, Turbellaria, Trematoda, and Monogenea examples of Platyhelminthes.
Do flatworms have a complete digestive system?
Physiological Processes of Flatworms Most flatworms have an incomplete digestive system with an opening, the “mouth,” that is also used to expel digestive system wastes. Some species also have an anal opening.
What are 5 characteristics of cnidarians?
The five main characteristics of cnidarians are:
- Radial symmetry.
- Diploblastic animals.
- Tissue level of organisation.
- Presence of cnidoblasts with stinging nematocysts on the tentacles.
- Polymorphism and have two body forms, i.e. polyp and medusa.
What are the two main characteristics of cnidarians?
What are the Characteristics of Cnidarians?
- They are characterized by the presence of stinging cells called Cnidoblast and a cavity called coelenterates, justifying the name Cnidaria or Coelenterata.
- They are exclusively aquatic and marine.
- They are radially symmetrical and diploblastic animals.
How do you classify cnidarians?
Cnidarians are classified into four main groups: the almost wholly sessile Anthozoa (sea anemones, corals, sea pens); swimming Scyphozoa (jellyfish); Cubozoa (box jellies); and Hydrozoa (a diverse group that includes all the freshwater cnidarians as well as many marine forms, and has both sessile members, such as Hydra …