Why is it unusual for a bilaterally symmetrical organism to have a feeding tube located as does the planaria?

1. Why planarians are said to have an amazing regenerative capacity and what is its importance to humans?
2. What structure do Planaria use for feeding?
3. What do they say about the symmetry of the Planaria?
4. What is the name of the tube used for feeding in the planarian?
5. What does planarian regeneration tell us about human regeneration?
6. What is the process of regeneration and why is it important?
7. Do flatworms have bilateral symmetry?
8. What specific structures allow a planarian to sense food or other chemicals where on its body are these structures?
9. Are nematodes bilaterally symmetrical?
10. What does bilateral symmetry mean in biology?
11. Do roundworms have bilateral symmetry?
12. Do Planaria prefer environments exposed to light or environments that are dark?
13. Where does respiration occur in the planarian?
14. How does the planarian feed?
15. Which characteristic applies to roundworms?

Why planarians are said to have an amazing regenerative capacity and what is its importance to humans?

Neoblasts account for 25–30% of all cells in the planarian body and every tissue is ultimately derived from these cells. The capacity of this cell type to self-renew, rapidly proliferate, and migrate to sites of injury gives planarians the unmatched ability to regenerate.

What structure do Planaria use for feeding?

To ingest (swallow) food, the planarian extends its pharynx out of its mouth. The pharynx is a muscular tube that is used by the planarian to swallow prey animals whole (in the case of small animals) or to suck in body juices of a larger animal. The ingested food winds up in the animals gastrovascular cavity (GVC).

What do they say about the symmetry of the Planaria?

First, planarians have bilateral symmetry with two nerves extending the length of the body, an enlarged "brain" (ganglion cell), and two eye spots. The eye spots are sensitive to light.

What is the name of the tube used for feeding in the planarian?

The planarian's pharynx, a feeding tube that extends from its gastrovascular cavity (digestive tract) tract), is easily visible connecting the mid-section of the worm to the food. These flatworms feed through their pharynx, which is located in the midsection of their body, not on their head.

What does planarian regeneration tell us about human regeneration?

A planarian can regrow any missing body part. In fact, if you take a planarian and amputate it into several little pieces, each one of those body fragments is able to regenerate into a whole new worm. ... Many of the same genes and developmental processes that drive regeneration in planarians are present in humans as well.

What is the process of regeneration and why is it important?

Regeneration is the natural process of replacing or restoring damaged or missing cells, tissues, organs, and even entire body parts to full function in plants and animals. Scientists are studying regeneration for its potential uses in medicine, such as treating a variety of injuries and diseases.

Do flatworms have bilateral symmetry?

The group includes freshwater planarians and colorfully patterned marine flatworms. It also contains parasitic worms that live inside the bodies of an estimated 200 million humans around the world. Flatworms' bodies are bilaterally symmetrical and they have a defined head and tail region.

What specific structures allow a planarian to sense food or other chemicals where on its body are these structures?

Planarians can sense and respond to chemical stimuli in their environment by using chemoreceptors mainly localized on the sides of their bodies (auricles). Their bodies also contain structures called protonephridia, which function like kidneys by removing fluid waste and regulating salts and water intake.

Are nematodes bilaterally symmetrical?

Like the flatworms, nematodes are bilaterally symmetrical. They take their name from their round body cross-sectional shape. Unlike the flatworms in which food and waste enter and exit from the same opening, nematodes have a complete digestive system.

What does bilateral symmetry mean in biology?

Definition of bilateral symmetry

: symmetry in which similar anatomical parts are arranged on opposite sides of a median axis so that only one plane can divide the individual into essentially identical halves.

Do roundworms have bilateral symmetry?

Roundworms (nematodes) are bilaterally symmetrical, worm-like organisms that are surrounded by a strong, flexible noncellular layer called a cuticle. Their body plan is simple.

Do Planaria prefer environments exposed to light or environments that are dark?

Background. Planarians, like rodents, instinctively spend more time in dark versus light environments when given a choice. This behavioral phenomenon is called negative phototaxis, which may reflect defensive responding related to an anxiety-like phenotype.

Where does respiration occur in the planarian?

Respiration occurs on the cilia of a planarian. How do ALL cells of the planarian obtain oxygen?

How does the planarian feed?

The digestive system consists of a mouth, pharynx, and a gastrovascular cavity. ... Planaria eat living or dead small animals that they suck up with their muscular mouths. Food passes from the mouth through the pharynx into the intestines where it is digested by the cells lining the intestines.

Which characteristic applies to roundworms?

Features of Roundworms

Unlike the flatworms, the roundworms have a body cavity with internal organs. A roundworm has a complete digestive system, which includes both a mouth and an anus. This is a significant difference from the incomplete digestive system of flatworms.