Question

differentiate between porifera and colenterta

Answer 1

Both Porifera and Coeleterata are two phyla in the kingdom of Animalia. The animals in the phylum: Porifera are usually called sponges. The animals belonging to the phylum: Coelenterata is identified as Cnidaria. Sponges are sessile metazoans, which lack body symmetry. Some Cnidarians are sessile whereas others are free-swimming. Cnidarians consist of radial symmetry. The key difference between Porifera and Coelenterata is that Porifera consist of numerous pores throughout the body, working as water intake and outlet openings whereas Coelenterata consist of a single opening on the body working as mouth/anus.

Answer 2

Answer:

Porifera:

Sponges, or “ The Pore Bearers” are  among the oldest multicellular species,  with fossils dating back over 600  million years ago. They are made up of  over 9000 different species and can  range in size from 0.5cm tall to 2m  tall.Porifera are “asymmetrical” meaning there is  no symmetry in their body structure. This is  due to the fact that they have no true  mesoderm or a “body plan.” Porifera do not have any form  of nervous system but their  individual cells have the ability  to sense and react to stimuli in  the environment. Porifera are only motile in their laval form. The mature form is sessile (non-moving) which is one of the main reasons for these animals being originally classified as plants. Porifera do not have a true respiratory system. Gas exchanges directly between cells and water by diffusion (O2 diffuses into and CO2 out of cells). Water enters via tiny pores called ostia, incurrent. Water exits via a massive pore, osculum, excurrent. Porifera do not have a true excretory system. They have specialized cells, amebocytes, which help remove waste from other cells in the sponge, or cells release waste directly to water. Wastes are then carried away out of the osculum by water currents. Water enter via ostia, incurrent. Water exits via osculum, excurrent. Porifera are filter-feeders meaning their food enters with water and they filter the food out. Water enters via tiny pores, ostia, incurrent. Water exits via massive pore,osculum, excurrent. Collar cells (choanocytes) engulf and digest the food. Digestion in sponges occurs when the flagella of choanocytes draws water through the holes in the body wall, then expels it through the osculum. Here, specialized collar cells trap food particles and digest them, or pass them on to an ameboid-like cell for digestion and circulation. Asexual and sexual reproduction both occur in sponges. Asexual reproduction occurs by fragmentation or budding. In fragmentation, a piece breaks off and forms a separate animal. In budding, the animal reproduces by growing a second sponge from the side of the parent that eventually detaches. In sexual reproduction, an egg and sperm combine to form a flagellated zygote which swims to a new location. The first stage of life for a porifera is as a free swimming larvae. Once attached to a solid object such as a rock, the larvae can grow into a young, and eventually mature sponge.

Cnidaria:

This phylum includes animals such as coral, jellyfish, coral, and hydroids. The name “Cnidae” refers to their “stinging nettles” Cnidaria are classified as a “more complex” phylum than porifera.Cnidarians are either vase shaped or bell shaped and have radial symmetry (producing two equal parts if cut longitudinally) Cnidarians range in size from as small as a 0.5cm tall bell up to a 2.4 m diameter with tentacles ranging upwards of 50 meters.Cnidaria have simple nervous system called a nerve net. These nerve cells react to the presence of food and danger for the purposes of feeding and protection. Although they lack a true muscular system, cnidarians are able to move using specialized cells that can contract and relax (eg. in the tentacles). Cnidaria do not have a true respiratory system. Gas exchanges directly between cells and water by diffusion (O2 diffuses into and CO2 out of cells) both across epidermis and gastrovascular tissues. Cnidaria do not have a true excretory system. Their waste diffuses from cells into gastrovascular cavity and is then released through the mouth. Many Cnidarians are carnivorous predators. They capture small animals using their nematocysts (stinging cells). They then use their tentacles to push food through their mouth into their gastrovascular cavity. Cnidarians do not have a true digestive system. Food enters their gastrovascular cavity via mouth and extracellular digestion enzymes are secreted into their gastrovascular cavity. Cells lining the cavity absorb the digested nutrients and smaller food particles. Reproduction in cnidarians takes place sexually or  asexually by budding. Cnidarians alternate between medusa and polyp forms in their life cycle.