Why nematode are called tube within a tube?

Why nematode are called tube within a tube?

Nematodes have been characterized as a tube within a tube ; referring to the alimentary canal which extends from the mouth on the anterior end, to the anus located near the tail. Nematodes possess digestive, nervous, excretory, and reproductive systems, but lack a discrete circulatory or respiratory system.

What type of body cavity is the tube within a tube arrangement?

It refers to the development of a fluid-filled cavity between the outer body wall and the digestive tube. The nature of this body cavity has led to the grouping of metazoa into three grades, acoelomate, pseudocoelomate, and eucoelomate (figure from Brusca and Brusca,1990) .

Which organisms have tube within tube body plan?

Tube – within – tube body plan is shown by phylum Annelida. These are the characteristics of Annelida: Free-living, terrestrial or aquatic form (freshwater or marine). The body is long, cylindrical and metamerically segmented.

Is there a tube within a tube body plan in Ascaris?

In the tube within a tube body plan there are two openings one for food to enter the body and other for wastes to leave the body example- roundworms. The tube within tube plan allows specialization of parts along the tube like stomata, intestine etc. (4) Ascaris is a genus of parasitic roundworms pseudocoelomates.

What does it mean by tube within a tube?

body plan
Most animals have a body plan best described as a “tube-within-a-tube”. This plan calls for two openings: one for food to enter the body (mouth), one for wastes to leave the body (anus). Sac-like body plan animals do not have tissue specialization or development of organs.

Why is the tube within a tube plan more efficient?

Body Plans Animals with the “tube-within-a-tube” plan are 10% more efficient at digesting and absorbing their food than animals with the sac-like body plan. The tube-within-a-tube plan allows specialization of parts along the tube. Sac-like body plan animals do not have tissue specialization or development of organs.

What is Enterocoelom?

Enterocoelom is a process by which some animal embryos develop. In enterocoely, a mesoderm (middle layer) is formed in a developing embryo, in which the coelom forms from pouches “pinched” off of the digestive tract.

How is a roundworms digestive tract like a tube within a tube?

All roundworms develop from three germ layers. How is a roundworm’s digestive tract like a tube-within-a-tube? The inner tube s the digestive tract, and the outer tube is the body wall.

Which of the following does not represent a tube within tube body plan?

The tube in a tube body plan is referred to a fluid-filled cavity, present between the digestive tract and outer body of the organism. It is present in organisms of phylum Nematoda, such as tube worms (Taenia), Ascaris, and C. Leech does not show tube body plan. Thus, the correct answer is ‘option C).

What are the advantages of having a body cavity and a complete tube within a tube digestive tract?

Body Plans Animals with the “tube-within-a-tube” plan are 10% more efficient at digesting and absorbing their food than animals with the sac-like body plan. The tube-within-a-tube plan allows specialization of parts along the tube. The sac-like body plan has only one opening for both food intake and waste removal.

What does a tube within a tube mean?

The tube within a tube “plan,” in its most basic form, means that food goes in one end and exits at the other end. The tube portion means that as the food travels along its tract, it’s contained in a very specialized section of the anatomy. It may pass through several designated chambers as it is digested and broken down.

What does it mean when food passes through a tube?

The tube portion means that as the food travels along its tract, it’s contained in a very specialized section of the anatomy. It may pass through several designated chambers as it is digested and broken down. This is opposite of the “sac system,” in which animals eat food, digest it, then excrete it through the same opening.

What does the tube within a worm mean?

This is a well-recognized part of annelid, or segmented worm, body structure. In fact, on a broader scale, it could be used to describe animal and human systems as well. The tube within a tube “plan,” in its most basic form, means that food goes in one end and exits at the other end.

How does a sac-like body plan differ from a tube within a tube?

This plan calls for two openings: one for food to enter the body (mouth), one for wastes to leave the body (anus). The tube-within-a-tube plan allows specialization of parts along the tube, such as a stomach, intestine, etc. The sac-like body plan has only one opening for both food intake and waste removal.