Nutrition is an essential property of all living things. This is a sign that determines the systematic position and level of organization of the kingdoms of nature. Having become acquainted with the material of the article, you compare the nutrition of sponges and intestinal - the first multicellular animals.
General structural features
These two types of animals have many similar characteristics. Their bodies are made up of many cells. They do not yet form tissues, but are specialized. Each cell functions independently, but together they form two layers of the body: the outer and the inner. In the first are cutaneous-muscular and intermediate cells. In the internal digestive and glandular prevail.
Natural Filters
Compare the nutrition of sponges and intestinal, and you will see that in the implementation of this process they have many similar and distinctive features. Their habitat is water. Sponges lead an attached lifestyle. For this reason, scientists for a long time could not determine who they are: plants or animals. The green color of some sponges also led them astray. It turned out that its cause is algae that settle in their cells.
Sponges - Filters. They feed on organics suspended in water and small vertebrates. At the same time, sponges pass water through themselves. By carrying out this process, they cleanse water bodies. Only one small sponge of leukonium, whose height barely reaches 10 cm, can drive about 20 liters of water through the body per day.
Some species are able to interconnect with other organisms, and mutually beneficial. For example, a sponge provides algae with minerals and carbon dioxide needed for photosynthesis. And she herself receives ready-made organics from plants.
First predators
According to the structural features, two life forms of intestinal are distinguished. These are polyps and jellyfish. The similarity of sponges and coelenterates is that they lead an attached lifestyle. But these organisms feed in a different way. In the outer layer of their body there are stinging cells, with the help of which the intestinal cavity paralyze their victim. Even the smallest polyps, the size of which barely reaches a few centimeters, are predators.
Intestinal: type of nutrition
Two types of these animals can only absorb ready-made organic matter. But they get them in different ways. Compare the nutrition of sponges and coelenterates, and you will see how much the latter are more complex. Consider the process of their nutrition on the example of freshwater hydra. It got its name due to the presence of the intestinal cavity, which opens outward with a mouth opening surrounded by tentacles.
The stinging cells are formed by a capsule, inside of which there is a twisted thread. When the prey touches the sensitive hair, it unwinds and forces itself into the victim’s body. They swallow the prey whole. Under the influence of digestive enzymes that produce glandular cells, the victim’s body breaks up into pieces. This is the first step in digesting food. Further, digestive cells with the help of pseudopods capture it. This process ends in specialized vacuoles. Undigested food debris is removed through the mouth opening.
The action of stinging cells can be dangerous for humans, causing severe burns and poisoning.
Intestinal, sponges: the main similarities and differences
Both of these types of animals are heterotrophs. Compare the nutrition of sponges and intestinal, and you will see that in the implementation of this process they have a number of similar and distinctive features. They can only eat ready-made organic substances. The presence of a body cavity into which food enters unites them. Undigested residues are removed through the same opening through which they enter the body. A common feature is the presence of cells with flagella, which “fit” food particles to their decay site.
A distinctive feature of sponges and coelenterates is in the method of extracting food. The first filter it out from a continuous stream of water. The latter lead a predatory lifestyle, paralyzing the victim with the poison of stinging cells. Due to the fact that the gastrointestinal are more complex, the digestion process is much more complicated and effective. In addition, their cells are more diverse in their specialization. For all intestinal cavities, both abdominal and cellular digestion are characteristic. This determines a higher intensity of the process. In addition to digestive, there are also glandular cells. They secrete enzymes - biological catalysts that accelerate the reaction. Thus, intestinal cavities have, albeit in a simplified form, their own system of digestive glands. In general, these organisms, being the first multicellular representatives of the animal world, are characterized by a rather complex process of digestion of food.