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How many germ layers does platyhelminthes have?

How many germ layers does platyhelminthes have?

Flatworms have three embryonic tissue layers that give rise to surfaces that cover tissues (from ectoderm), internal tissues (from mesoderm), and line the digestive system (from endoderm).

Do flatworms have two germ layers?

Flatworms have three germ layers. Like cnidarians flatworms have a layer of ectoderm and endoderm, but also a third germ layer called mesoderm.

What is the excretory system of platyhelminthes?

Flatworms have an excretory system with a network of tubules throughout the body that open to the environment and nearby flame cells, whose cilia beat to direct waste fluids concentrated in the tubules out of the body. The system is responsible for regulation of dissolved salts and excretion of nitrogenous wastes.

Are platyhelminthes diploblastic or triploblastic?

Platyhelminthes (Gr. Platy- flat; helminthes- worm) They are advanced diploblastic or lower triploblastic, acoelomate and bilaterally symmetrical metazoan.

How many germ layers do members of the phylum platyhelminthes possess what are they called 4?

three embryonic
Like other advanced multicellular animals, they possess three embryonic layers—endoderm, mesoderm, and ectoderm—and have a head region that contains concentrated sense organs and nervous tissue (brain).

How many germ layers do Cnidaria have?

two germ layers
Cnidarians nominally develop from two germ layers, the ectoderm and endoderm, whereas the presence of a third germ layer, the mesoderm, traditionally characterizes higher animals.

How do Platyhelminthes respire?

Flatworms are small, literally flat worms, which ‘breathe’ through diffusion across the outer membrane. The flat shape of these organisms increases the surface area for diffusion, ensuring that each cell within the body is close to the outer membrane surface and has access to oxygen.

What are the three classes of Platyhelminthes?

The Platyhelminthes includes three classes: the Turbellaria (free-living flatworms), the Trematoda (flukes), and the Cestoda (tapeworms).

Which phylum contain Acoelomate and triploblastic animals?

NEET Question. Option B , Phylum Platyhelmithes . This Phylum Consists Of Acoelomate & Triploblastic Organisms.

In which Platyhelminthes mouth and alimentary canal are completely absent?

(8) The digestive system is completely absent from Cestoda and Acoela. The alimentary canal is branched in Turbellarians. The anus is absent from them.

Where are the three germ layers found?

Germ layer, any of three primary cell layers, formed in the earliest stages of embryonic development, consisting of the endoderm (inner layer), the ectoderm (outer layer), and the mesoderm (middle layer).

What are the three embryonic germ layers?

Written By: Germ layer, any of three primary cell layers, formed in the earliest stages of embryonic development, consisting of the endoderm (inner layer), the ectoderm (outer layer), and the mesoderm (middle layer).

Which phyla have only two germ layers?

Diploblastic organisms have only the two primary germ layers; these organisms characteristically have multiple symmetrical body axes (radial symmetry), as is true of jellyfish, sea anemones, and the rest of the phylum Cnidaria .

What is the innermost primary germ layer?

The allantois, a tube of endoderm (the innermost germ layer), grows out of the early yolk sac in a region that soon becomes the hindgut. The tube extends into a bridge of mesoderm (the middle germ layer) that connects embryo with chorion and will become incorporated into the umbilical cord.

Which primary germ layer forms the reproductive system?

mesoderm. middle primary germ layer that gives rise to notochord, skeletal system, circulatory system, dermis of skin, muscular system, reproductive system, excretory system, connective tissue. when sperm penetrates the corona radiata and zona pellucida of oocyte.