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Dugesia, a genus of freshwater planarians, can be distinguished at its anterior end by the presence of eye spots (ocelli), which detect light, and a protruding structure called the pharynx, used for feeding. In contrast, the posterior end is generally more tapered and lacks these sensory and feeding features. Additionally, the anterior end is typically broader and more rounded compared to the narrower, pointed posterior end.
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How does the position of the mouth of Dugesia and flukes compare?
Dugesia and flukes are both types of flatworms. They both only have one opening that holds both the process of ingestion and secretion. The mouth of the Dugesia is on the ventral side, close to to middle of the body. While the fluke's mouth appears to be closer to what one would assume is the head.
Is gastrovascular cavity of dugesia a simple sac?
No, the gastrovascular cavity of Dugesia is not a simple sac. It is a more complex structure that serves both as a digestive chamber and a circulatory system. This cavity has branches that allow for the distribution of nutrients and removal of waste throughout the organism.
What type of symmetry does the dugesia have?
Dugesia, also known as planaria, are known to exhibit bilateral symmetry, meaning the body can be divided into two equal halves along a single plane. This type of symmetry is common in many animals, including humans, and helps with efficient movement and sensory perception.
What process are nutrients distributed to the epidermal cells in dugesia?
In Dugesia, or planarians, nutrients are distributed to epidermal cells primarily through a process called diffusion. The gastrovascular cavity, which is a central digestive space, breaks down food and allows nutrients to diffuse into surrounding tissues, including the epidermis. This diffusion occurs because of the concentration gradient, with nutrients moving from areas of higher concentration in the gastrovascular cavity to lower concentration in the epidermal cells. Additionally, the extensive branching of the gastrovascular system facilitates efficient nutrient distribution throughout the organism.
What is the ecological importance of planarians?
Planaria sp. is a common freshwater, non-parasitic member of the phylum Platyhelminthes, class Turbellaria. It should be noted that the term "planaria" is most often used as a common name, much in the same way as trout. It is also the name of a genus within the family Planariidae. It moves by beating cilia on the ventral dermis, allowing it to glide along on a film of mucus. Some move by undulations of the whole body by the contractions of muscles built into the body wall. They exhibit an extraordinary ability to regenerate lost body parts. For example, a Planaria split length wise or crosswise will regenerate into 2 separate individuals. The size ranges from 3 to 12 mm, and the body has two eye-spots (also known as ocelli) that can detect the intensity of light. The eye-spots act as photoreceptors and are used to move away from light sources. Planaria have 3 germ layers (ectoderm, mesoderm, and endoderm), but lack a body cavity or coelom. They have a single-opening digestive tract, consisting of one anterior branch and two posterior branches in freshwater planarians. Because of this three-branched organization, freshwater flatworms are often referred to as triclad planarians.Planaria are common to many parts of the world and reside in fresh water ponds and rivers. They are also commonly found residing on plants.The most frequently used in the high school and first-year college laboratories is the brownish Dugesia tigrina. Other common varieties are the blackish Planaria maculata and Planaria dorotocephala. Recently, however, the species Schmidtea mediterranea has emerged as the species of choice for modern molecular biological and genomic research due to its diploid chromosomes and existence in both asexual and sexual strains. Recent genetic screens utilizing double-stranded RNA technology have uncovered 240 genes that affect regeneration in S. mediterranea. Interestingly, many of these genes are found in the human genome (see link below).Contents[show]* 1 Organ Systems* 2 See also* 3 External links* 4 References[edit]Organ SystemsThe planarian has very simple organ systems. The digestive system consists of a mouth, pharynx, and an intestine. The mouth is located in the center of the underside of the body. Digestive enzymes sercrete from mouth to begin external digestion. The pharynx connects the mouth to the intestines. The intestines of the Planaria branch throughout the body. They eat living or dead small animals which they suck with their muscular mouth. From there the food passes through the pharynx into the intestines and digesting of the food takes place in the cells lining the intestine, which then diffuses to the rest of the body. The undigested food leaves through the pharynx and mouth.Planaria receive oxygen and release carbon dioxide by diffusion. The excretory system is made of many tubes with many flame cells and excretory pores on them. Flame cells remove unwanted liquids from the body by passing them through ducts that lead to excretory pores where the waste is released on the dorsal surface of the planarian.At the head of the planarian there is a brain under the eyespots. From the brain there are two nerve cords which connect at the tail. There are many transverse nerves connected to the nerve cords which make it look like a ladder. With a ladder-like nerve system it is able to respond in a coordinated manner.A planarian can reproduce either asexually or sexually. In asexual reproduction the planarian detaches its tail end and each half regrows the lost parts. In sexual reproduction each Planaria gives and receives sperm. Planaria have both testes and ovaries. Eggs develop inside the body and are shed in capsules. Weeks later the eggs hatch and grow into adults. Planarians can also reproduce by regeneration. If a Planaria is cut into two halves both halves may become two new Planaria (regeneration). In one experiment, T.H. Morgan found that a piece corresponding to 1⁄279th of a planarian could successfully regenerate into a new worm. This size (about 10,000 cells) is typically accepted as the smallest fragment that could regrow into a new planarian. Source(s):That's what I found...www.wikipedia.org
What features of dugesia distinguish its head from its tail?
Dugesia has distinct features that differentiate its head from its tail. The head typically has a pair of eyespots that detect light, while the tail tends to be more tapered and lacks sensory organs. In addition, the head region may exhibit a more active behavior, such as seeking out food sources, compared to the tail.
How does the position of the mouth of Dugesia and flukes compare?
Dugesia and flukes are both types of flatworms. They both only have one opening that holds both the process of ingestion and secretion. The mouth of the Dugesia is on the ventral side, close to to middle of the body. While the fluke's mouth appears to be closer to what one would assume is the head.
When was Dugesia aenigma created?
Dugesia aenigma was created in 1984.
When was Dugesia sicula created?
Dugesia sicula was created in 1948.
When was Dugesia notogaea created?
Dugesia notogaea was created in 1998.
When was Dugesia tubqalis created?
Dugesia tubqalis was created in 2012.
When was Dugesia golanica created?
Dugesia golanica was created in 1991.
When was Dugesia sagitta created?
Dugesia sagitta was created in 1861.
When was Dugesia japonica created?
Dugesia japonica was created in 1964.
Dugesia will display phototaxis?
Dugesia will exibit negative phototaxis. Look it up in a zoology book. here is an article as well. http://www.helium.com/items/1079086-the-observation-of-dugesia-in-response-to-light-and-gravity
How does Dugesia lives?
Dugesia, a genus of planarian flatworms, typically lives in freshwater environments such as ponds, lakes, and streams. They are carnivorous, feeding on small organisms like insects and worms. Dugesia are known for their ability to regenerate lost body parts, making them resilient creatures in their ecosystem.
What is the scientific name for Planiria?
Perhaps the best-known of the non-parasitic flatworms ka planaria are the brown-colored Dugesia tigrina, and the black-colored Dugesia dorotocephala and Planaria maculata.
