Why are cnidarians Diploblastic?
Cnidarians are generally regarded as diploblastic animals, possessing endoderm and ectoderm, but lacking mesoderm. mef2 is restricted to the ectoderm. The temporal and spatial expression of these ‘mesoderm’ genes suggests that they may play a role in germ layer specification.
What are the two main morphological patterns of cnidarians?
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.
Do cnidarians have tissues?
Cnidarians are said to be the simplest organisms at the tissue grade of organization; their cells are organized into true tissues. Cnidarians are essentially bags made of two cell layers. The outer ectoderm, or epidermis, contains the cnidocysts, the stinging cells that are characteristic of the phylum.
Does porifera have true tissue?
Unlike Protozoans, the Poriferans are multicellular. However, unlike higher metazoans, the cells that make up a sponge are not organized into tissues. Therefore, sponges lack true tissues and organs; in addition, they have no body symmetry. Sponges do, however, have specialized cells that perform specific functions.
Do platyhelminthes have true tissues?
Porifera (sponges) have specialized cells and an endoskeleton but lack true tissues and body symmetry. Platyhelminthes (flatworms) have a mesoderm cell layer, simple organ systems, cephalization, and bilateral symmetry.
Do chordates have true tissues?
Nematodes have no true tissues and are filter feeders, while chordates have true tissues and a gastrovascular cavity. Sponges have no true tissues and are filter feeders, while cnidarians have true tissues and a gastrovascular cavity.
Which phyla of animals are most closely related?
Which worm has no body cavity?
Which is the most advanced class in the animal kingdom?
The biggest class of animal kingdom is? Answer: Insecta is a class of invertebrates. They are placed within the phylum Arthropoda. The characteristics of group Insecta are that they have six legs or three pairs of legs.
What is the most specific animal classification?
There are 7 major hierarchies, or ranks, in animal classification. Kingdom is the highest and most inclusive rank. Phylum is the rank below kingdom, and species is the most fundamental rank….Animal Phyla.
What are the 7 levels of the classification system?
There are seven main taxonomic ranks: kingdom, phylum or division, class, order, family, genus, species.
Which two kingdoms in the table are probably most closely related?
In the maximum-likelihood trees for both large- and small-subunit rRNAs, Animalia and Fungi were the most closely related eukaryotic kingdoms, and Plantae is the next most closely related kingdom, although other branching orders among Plantae, Animalia, and Fungi were not excluded by this work.