What is the space inside coelenterates?

The organisms of the phylum Cnidaria (or Coelenterata) are characterized by apparent radial symmetry of body forms and simple structures consisting of two layers of cells surrounding an internal space (coelenteron) which also functions as a digestive cavity.

1. What is the single internal cavity of cnidarians called?
2. Is sexes are separate in Coelenterata?
3. Why is Coelenteron called gastrovascular cavity?
4. Do coelenterates have tentacles?
5. Do cnidarians have internal or external fertilization?
6. What is polymorphism in Cnidaria?
7. What are tentacles in coelenterates?
8. What is found in Coelenterata?
9. What is polyp and medusa?
10. What is Coelenteron function?
11. What functions does the Coelenteron have?
12. What is Coelenteron?
13. Which type of fertilization is occur in Coelenterates?
14. Do Coelenterates breathe?
15. Why Coelenterates are also called cnidarians?

What is the single internal cavity of cnidarians called?

Cnidarians have an incomplete digestive system with only one opening; the gastrovascular cavity serves as both a mouth and an anus.

Is sexes are separate in Coelenterata?

Anthozoa or Actinozoa belongs to Class II of the Coelenterates. ... Anthozoa protects its soft body tissues and lends support to its body by secreting nonliving substances around and outside its body. Not all Anthozoa belong to the same sex. Some are hermaphroditic while others are segregated into separate sexes.

Why is Coelenteron called gastrovascular cavity?

Complete answer: Coelenteron is the gastrovascular cavity present in the Cnidarians having a single opening called the mouth. ... The coelenteron is considered as a gastrovascular cavity because it is where both digestion and gas exchange between the organism's cells and water in the cavity takes place.

Do coelenterates have tentacles?

Characteristics. All coelenterates are aquatic, mostly marine. The bodyform is radially symmetrical, diploblastic and does not have a coelom. The body has a single opening, the hypostome, surrounded by sensory tentacles equipped with either nematocysts or colloblasts to capture mostly planktonic prey.

Do cnidarians have internal or external fertilization?

In other cnidarians the male releases sperm into the water, but fertilization happens inside the body when sperm from a male colony enters the female and fertilizes eggs internally.

What is polymorphism in Cnidaria?

Polymorphism refers to the occurrence of structurally and functionally more than two different types of individuals within the same organism. It is a characteristic feature of Cnidarians, particularly the polyp and medusa forms, or of zooids within colonial organisms like those in Hydrozoa.

What are tentacles in coelenterates?

Tentacles have special structures known as the nematocysts which help in capturing and paralyzing prey. Coelenterates simply wave their tentacles and when a prey comes in contact, the nematocysts inject the toxin that paralyses or kills the prey. Nematocysts are the most distinguishing feature of this phylum.

What is found in Coelenterata?

Coelenterates are called Cnidarians because they contain specialized cells called cnidoblasts. They possess stinging structures called nematocysts.

What is polyp and medusa?

There are two basic cnidarian body shapes: a polyp form, which is attached to a surface; and an upside-down free-floating form called a medusa. Some cnidarians change form at different phases of their life cycle, while others remain in one form for their entire life.

What is Coelenteron function?

The cnidarian digestive cavity, called the coelenteron, has a single mouth opening through which food/prey enters and waste is expelled. The coelenteron is considered a gastrovascular cavity because it is where both digestion and gas exchange between the organism's cells and water in the cavity take place.

What functions does the Coelenteron have?

Digestion, respiration, and excretion

Food is taken in and wastes are discharged through the mouth. Extracellular digestion occurs in the coelenteron, which has, in all except hydrozoans and some tiny members of the other classes, radial projections of the wall into the coelenteron that increase the surface area.

What is Coelenteron?

Definition of coelenteron

: the internal cavity of a cnidarian.

Which type of fertilization is occur in Coelenterates?

External fertilization mostly. Two sexual stages are found that is polyp and medusa. They show alteration of generations i. e. polyp produce medusa asexually and medusa produce polyp sexually. In hydra and adamsia polyp stage is present while in aurelia medusa stage is present.

Do Coelenterates breathe?

Mechanisms of breathing vary among different groups of animals depending mainly on their habitats and levels of organisation. Lower invertebrates like sponges, coelenterates, flatworms, etc., exchange O2 with CO2 by simple diffusion over their entire body surface.

Why Coelenterates are also called cnidarians?

Phylum Coelenterata is also known as Cnidaria due to the presence of cnidoblasts or cnidocytes on the tentacles and body surface. They contain stinging capsules called nematocysts.