How is polymorphism expressed in the phylum Cnidaria?
All cnidarians have two membrane layers, with a jelly-like mesoglea between them. Some cnidarians are polymorphic, that is, they have two body plans during their life cycle. An example is the colonial hydroid called an Obelia. The sessile polyp form has, in fact, two types of polyps, shown in Figure 28.2.
What is the significance of the presence of both the polyp and medusa form in the life of a cnidarian such as Hydra State also the similarities that exist between these forms?
Some cnidarians are dimorphic, that is, they exhibit both body plans during their life cycle. In these species, the polyp serves as the asexual phase, while the medusa serves as the sexual stage and produces gametes.
Which organism possesses both a polyp and medusa phase of life?
They are the most primitive of animals whose cells are organized into distinct tissues, but they lack organs. Cnidarians have two body forms—polyp and medusa—which often occur within the life cycle of a single cnidarian. Sea nettle (Chrysaora fuscescens).
What is the body plan of cnidarians?
Cnidarians have two distinct body plans, the medusa (a) and the polyp (b). All cnidarians have two membrane layers, with a jelly-like mesoglea between them. Animals in this phylum display two distinct morphological body plans: polyp or “stalk” and medusa or “bell” (Figure 2).
What is polymorphism in phylum Coelenterata?
The occurrence of more than one type of structurally and functionally different. individuals within a population is called polymorphism. The class Hydrozoa of phylum. Coelenterata includes a large number of colonial species that contain more than one form of. individuals which are called zooids.
What is difference between polyp and medusa shown by cnidarians?
While in other cnidarian classes such as cubozoa or rhizostomeae medusa are produced by the metamorphosis of the polyp. Difference Between Polyp and Medusa: Polyp is a sessile life stage of the cnidaria phylum whereas medusa is totally opposite i.e they have a mobile life cycle stage of the cnidaria phylum.
What is the difference between polyp and medusa stage?
Polyps have a tubular shape and are fixed at their base. Their mouth is present at the other end of the tube, and is surrounded with tentacles forming the “head”. Mouth and tentacles face the water. In contrast, medusa have the shape of a contracting muscular bell enabling it to swim.
What are the unique structures of phylum Cnidaria?
Cnidarians have two distinct body plans, the medusa (a) and the polyp (b). All cnidarians have two membrane layers, with a jelly-like mesoglea between them. Two distinct body plans are found in Cnidarians: the polyp or tuliplike “stalk” form and the medusa or “bell” form (Figure 2).
Which characteristic is shared by both cnidarians and flatworms?
Answer: D) A digestive system with a single opening is shared by both cnidarians and flatworms.
Do cnidarians have Coelom?
A coelom is a fully-encased, fluid-filled body cavity (gut) lined with mesodermic tissue. Cnidarians are not considered to have a coelom because they are diploblastic, so they don’t have any mesodermic tissue. Cnidaria are a phylum consisting of aquatic animals like jellyfish, anemones, and corals.
What is polymorphism in Cnidaria?
POLYMORPHISM IN CNIDARIA. Polymorphism is the phenomenon of occurrence of the same species of the organism in more than one form with different functions. Polymorphism is a Greek word, polys meaning many and morphe meaning form. This occurrence of polymorphism guarantees well-organized division of labor between several individuals.
Why is polymorphism important in the phylum Hydrozoa?
In coelenterates different individuals get united in the form of a colony and hence polymorphism is a very important feature of this phylum. Class hydrozoa is the best example of polymorphism. There are two main forms included in the polymorphism of the coelenterates namely Polyps and meduase.
What is the importance of polymorphism in coelenterates?
This occurrence of polymorphism guarantees well-organized division of labor between several individuals. In coelenterates different individuals get united in the form of a colony and hence polymorphism is a very important feature of this phylum.
What is polypolymorphism in biology?
Polymorphism is a Greek word, polys meaning many and morphe meaning form. This occurrence of polymorphism guarantees well-organized division of labor between several individuals. In coelenterates different individuals get united in the form of a colony and hence polymorphism is a very important feature of this phylum.