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Communication between nerve cells can occur by chemical synapses or gap junctions in hydrozoans, though gap junctions are not present in all groups. Cnidarians have many of the same neurotransmitters as many animals, including chemicals such as glutamate, GABA, and acetylcholine.
- How do cnidarians interact with each other?
- Do cnidarians have a nervous system?
- Can cnidarians be mobile?
- Are sexes separate in cnidaria?
- Are cnidarians asexual?
- Do cnidarians have muscles?
- Do cnidarians have a Coelom?
- How do cnidarians respond?
- Are Cnidaria autotrophic or heterotrophic?
- How do cnidarians breathe?
- Which cnidarians are attached?
- Do cnidarians have spicules?
- What did cnidarians evolved from?
- Do cnidarians have pores?
How do cnidarians interact with each other?
The relationship between cnidarians and dinoflagellate algae is termed as "symbiotic", because both the animal host and the algae are benefiting from the association. It is a mutualistic interaction. For some cnidarian species, it has been studied whether or not they could even survive without the dinoflagellate algae.
Do cnidarians have a nervous system?
Cnidarians have simple nervous systems and it was probably within this group or a closely-related ancestor that nervous systems first evolved.
Can cnidarians be mobile?
Cnidarians have two distinct morphological body plans known as polyp, which are sessile as adults, and medusa, which are mobile; some species exhibit both body plans in their lifecycle.
Are sexes separate in cnidaria?
Cnidarians have separate sexes and have a lifecycle that involves morphologically distinct forms. These animals also show two distinct morphological forms—medusoid and polypoid—at various stages in their lifecycle.
Are cnidarians asexual?
All cnidarian species are capable of sexual reproduction, which occurs in only one phase of the life cycle, usually the medusa. Many cnidarians also reproduce asexually, which may occur in both phases.
Do cnidarians have muscles?
Muscles in cnidarians are extensions of the bases of ectodermal and endodermal cells. Individual muscle cells are relatively long and may occur in dense tracts in jellyfish or sea anemones. Most cnidarian muscles, however, are thin sheets at the base of ectodermal and endodermal layers.
Do cnidarians have a 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.
How do cnidarians respond?
To respond to stimuli, cnidarians use a rudimentary muscular system consisting of muscle cells lying in bands up and down the body wall and in a circle around the mouth cavity (Fig. 3.27). The body shortens when the vertical bands contract. If muscles on only one side contract, the body bends in that direction.
Are Cnidaria autotrophic or heterotrophic?
The common characteristic to all of these animals is that they have stinging cells located, known as cnidocytes, on their tentacles. Because they belong to the animal kingdom, you can also assume that all cnidarians are multicellular and heterotrophic - meaning they must consume their food in some way.
How do cnidarians breathe?
Cnidarians don't have lungs, and even though they live in aquatic environments they don't have gills either. ... Instead of breathing, gas exchange in Cnidarians occurs through direct diffusion.
Which cnidarians are attached?
Many cnidarian species have two different body forms during their lives. One is the free-swimming form, called the medusa (a jellyfish for instance). The other is an attached form called the polyp (which resembles a tiny sea anemone). Both forms have a single opening that serves as the mouth and anus.
Do cnidarians have spicules?
Cnidarians have two basic body forms, medusa and polyp. Medusae, such as adult jellyfish, are free-swimming or floating. ... If collar cells and spicules are defining characteristics of the Phylum Porifera, then nematocysts define cnidarians.
What did cnidarians evolved from?
However, both cnidarians and ctenophores have a type of muscle that, in more complex animals, arises from the middle cell layer. As a result, some recent text books classify ctenophores as triploblastic, and it has been suggested that cnidarians evolved from triploblastic ancestors.
Do cnidarians have pores?
Sponges are unsymmetrical or radially symmetrical, with many cell types but no distinct tissues; their bodies contain numerous pores and sharp protective spicules. Coelenterates (phylum Cnidaria) are radially symmetrical, with two tissue layers (ectoderm and endoderm) surrounding an all-purpose gastrovascular cavity.
