What are the 3 germ layers and what do they become?
The three germ layers are the endoderm, the ectoderm, and the mesoderm. Cells in each germ layer differentiate into tissues and embryonic organs. The ectoderm gives rise to the nervous system and the epidermis, among other tissues. The mesoderm gives rise to the muscle cells and connective tissue in the body.
What type of germ layers do porifera have?
triploblastic) and body plans: With the exception of the phylum Porifera (sponges), all animals have tissues that derive from embryonic germ layers. Those with two embryonic germ layers are diploblastic; those with three embryonic germ layers are triploblastic.
What is porifera embryonic development?
The question of whether the cell movements during early embryonic development in sponges (Porifera) are gastrulation as in eumetazoans remains in dispute. These data show that sponges have no embryonic layers such as ectoderm or endoderm, characteristic to eumetazoans, and, consequently, no gastrulation.
What is the embryonic development of sponges?
Formation of embryonic layers in sponges has historically been attributed to a range of gastrulation processes, including epiboly, delamination and ingression, some of which require coordinated movement of sheets of cells (reviewed in Leys, 2004).
What does the endoderm become?
Endoderm cells give rise to certain organs, among them the colon, the stomach, the intestines, the lungs, the liver, and the pancreas. The ectoderm, on the other hand, eventually forms certain “outer linings” of the body, including the epidermis (outermost skin layer) and hair.
What does the ectoderm become?
Generally speaking, the ectoderm differentiates to form epithelial and neural tissues (spinal cord, peripheral nerves and brain). This includes the skin, linings of the mouth, anus, nostrils, sweat glands, hair and nails, and tooth enamel. Other types of epithelium are derived from the endoderm.
What are the main characteristics of phylum porifera?
Characteristic Features of Phylum Porifera
- They are generally marine aquatic organisms, with a few freshwater species.
- Their bodies are asymmetrical.
- Body shape can be cylindrical, vase-like, rounded or sac-like.
- They are diploblastic animals with two layers, the outer dermal layer and the inner gastral layer.
Does porifera have 3 germ layers?
Both the Cnidarians and Poriferans possess two germ layers including endoderm and ectoderm. Hence diploblastic. The Cnidarians include organisms like jellyfish, corals. The porifera includes animals like sponges.
Is germ layers present in Porifera?
Porifera are diploblastic. They have cells arranged in two germ/embryonic layers— endoderm and ectoderm.
What is the body cavity of Porifera?
Answer: Explanation: Poriferans have no true coelom hece called as Acoelomates. They have a small cavity called as spongocoel.
What is the process of embryo development?
The early stages of embryonic development begin with fertilization. After fertilization, the zygote undergoes cleavage to form the blastula. The blastula, which in some species is a hollow ball of cells, undergoes a process called gastrulation, in which the three germ layers form.
How are sponges formed?
The tiny larvae which are the result of fertilization are released into the water. The larvae use their cilia to propel themselves through the water. Eventually they settles down and grow to be an adult sponge.
How many germ layers does Porifera have?
With the exception of the phylum Porifera (sponges), all animals have tissues that derive from embryonic germ layers. Those with two embryonic germ layers are diploblastic;those with three embryonic germ layers are triploblastic.
When do the two germ layers develop in the embryo?
The germ layers develop early in embryonic life, through the process of gastrulation. During gastrulation, a hollow cluster of cells called a blastula reorganizes into two primary germ layers: an inner layer, called endoderm, and an outer layer, called ectoderm. Diploblastic organisms have only the two primary germ layers;
What kind of animal has three germ layers?
3) triploblastic = animals in which embryo has three distinct germ layers; ectoderm (outer) , mesoderm (middle) , endoderm (inner). 4) diploblastic = animals with two distinct layers (endoderm and ectoderm). Phylum Porifera (sponges).
What does coelom mean in the phylum Porifera?
Phylum Porifera(the sponges) Terminology 1) coelom = body cavity in tripoblastic animals; lined with a mesodermal peritoneum. 2) sponges coelom (spongocoel) = central cavity in sponges (not really true coelomic cavity because sponges and all other lower metazoans have diploblastic germ layers.