Which of the following statements correctly describes a characteristic of the phylum platyhelminthes?

Which of the following statements correctly describes a characteristic of the phylum Platyhelminthes? They typically reproduce asexually.

Which phyla have appendages?

The phylum Arthropoda contains a wide diversity of animals with hard exoskeletons and jointed appendages. Many familiar species belong to the phylum Arthropoda—insects, spiders, scorpions, centipedes, and millipedes on land; crabs, crayfish, shrimp, lobsters, and barnacles in water (Fig. 3.72).

Why cnidarians have diffused nervous system?

Answer: Because pin the cnidarian body, the nerve net serves as a sensory locator neuron cell stretch all around the animals body and allow the cnidarian to detect chemical change ,to capture prey, and to move in response to stimulus.

Why do arthropods have a ventral nervous system?

They can survive like this because of the branching nerves that run along the length of the arthropod body, many of which play just as powerful a role as the brain in nerve signaling. The ventral nerve cords and commissures transmit and coordinate messages from around the arthropod’s body.

Why do arthropods have jointed legs?

Jointed appendages allowed arthropods to have much greater flexibility and range of movement. Advantages of having a hard outer layer are protection, water retention, structural support (particularly on land), and counterforce for attachment and contraction of muscles.

Why do cnidarians have diffused nervous system?

Answer: Because pin the cnidarian body, the nerve net serves as a sensory locator neuron cell stretch all around the animals body and allow the cnidarian to detect chemical change ,to capture prey, and to move in response to stimulus.

Why is a cnidaria radial symmetry?

The body plan of cnidarians is unique because these organisms show radial symmetry, making these animals very different from those that evolved before them. Radial symmetry means that they have a circular body plan, and any cut through the center of the animal leaves two equal halves.

How do platyhelminthes breathe?

Flatworms are small, literally flat worms, which ‘breathe’ through diffusion across the outer membrane (Figure 20.3). 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.

Are platyhelminthes protostome or deuterostome?

Well known examples of protostomes are nematodes, arthropods, flatworms, annelids and molluscs.

Are flatworms multicellular or unicellular?

The flatworms, like the sponges (Phylum Porifera) and Phylum Cnidaria (Hydra, jellyfish, corals, and sea anemones) are multicellular. However, the flatworms are more complex in structure than either of the two other groups.

Are planarian worms immortal?

Planarians are also an emerging model organism for aging research. These animals have an apparently limitless regenerative capacity, and the asexual animals seem to maintain their telomerase levels throughout their lifetime, making them “effectively immortal”.

Are planarians free-living or parasitic?

The majority of members of the phylum Platyhelminthes (the flatworms—a phylum that includes the notorious tapeworms and flukes) are parasitic; planarians are labeled the only free-living (non-parasitic) flatworms in the bunch. Planarians are easily overlooked, but amazing, critters.

Are queen ants born queens?

The fertilized eggs become female worker ants and unfertilized eggs develop as males; if the fertilized eggs and pupae are well-nurtured, they potentially become queens.

Are turbellarians bottom dwellers?

In marine and freshwater habitats, where they exist as bottom dwellers, Turbellarians move by means of muscular undulations as well as by use of cilia which are located on the underside (ventral surface).

Can u cut a worm in half?

If an earthworm is split in two, it will not become two new worms. The head of the worm may survive and regenerate its tail if the animal is cut behind the clitellum. But the original tail of the worm will not be able to grow a new head (or the rest of its vital organs), and will instead die.

Do eyes breathe?

First off, your eye’s need to breathe! Yes, it’s true. Your cornea is the window to your vision and is exactly where your contact lenses sit. Like every other cell in your body, it relies on oxygen to stay healthy and function normally.

Do flatworms have brains?

Flatworms’ bodies are bilaterally symmetrical and they have a defined head and tail region. They have a central nervous system containing a brain and a nerve cord. Clusters of light-sensitive cells on either side of their head make up what are called eyespots.

Do flatworms need oxygen?

There is no need for a special circulatory system as a human has because the flatworm doesn’t breathe with lungs and doesn’t need to transport oxygen around its body. The flatworm simply diffuses oxygen via its skin.

Do humans have neoblasts?

In humans, no known pluripotent stem cells remain after birth. In planarians, they stick around into adulthood, where they become known as adult pluripotent stem cells or neoblasts. Scientists believe these neoblasts hold the secret to regeneration.

Do marine flatworms have eyes?

Flatworms have unusual ciliary cells outside their eyes which use a newly discovered protein to detect light. Eyes are elaborate organs that many animals use to detect light and see, but light can also be sensed in other, simpler ways and for purposes other than seeing.

Do parasites breathe oxygen?

“When parasites are outside the body, which they are for a part of their lifecycle, they breathe oxygen just like we do,” says Andrew Fraser, a senior author and a professor of molecular genetics in the Donnelly Centre for Cellular and Biomolecular Research at U of T’s Faculty of Medicine.

Do planaria like light or dark?

Planaria prefer the dark, as evidenced by the observation that they will move away from the light and to a dark side of the dish.

Do planarians eat each other?

A cannibal individual was separated from its prey which consisted of the head region of another planarian. This can- nibal planarian spent approximately five minutes examining each of the other planarians in the vicinity apparently trying to find the planarian upon which it had been feeding.

Do platyhelminthes have a respiratory system?

Flatworms have no specialized respiratory system; gases simply diffuse across the body wall.

Do the fish and frog breathe in the same way?

No, fish and frog do not breathe in the same way. Fishes have gills that help them to breathe. Frogs can live both on land and in water.

How are endoparasites transmitted?

Endoparasites are transmitted by the fecal-oral route, typically via contaminated food or water. Infection by Toxoplasma gondii is caused by ingestion of sporulated oocysts in cat feces or cyst-infected raw meat.

How are platyhelminthes important to humans?

Flatworms act as parasites in the human body, especially in their intestines and digestive tracts. They increase the chances for organic farming. They increased the popularity of raw cooked foods, such as the imports of meat, seafood, and vegetables.

How are respiration and circulation accomplished in flatworms?

Describe how respiration, circulation, and excretion are accomplished in the flatworm. many flame cells are joined together to form a network of tubes that empties into the outside environment through tiny pores in the animal’s cells.

How can endoparasites be prevented in mammals?

Endoparasites in your pet can be prevented and controlled by following a regular worming regime. Most pets should be wormed at least once every three months, however younger animals and those at a higher risk require more frequent worming. We advise that your pet is wormed on a monthly basis until 6 months old.