Contractile vacuole - protozoans, Biology

Contractile vacuole - Protozoans

The contractile vacuoles may differ in complexity in various groups of protozoans. In amoebae the vacuoles are carried around in the cytoplasm. 'Small vesicles join them emptying their contents into the vacuoles till the vacuole joins the membrane emptying its content to the outside.

In ciliates (e.g. Paramecium) the contractile vacuoles have a more complex structure. The contractile vacuole is located in a fixed position with an excretory pore leading to the outside surrounded by ampullae of feeder canals. The feeder canals are surrounded by a network of fine canals (20nm) in diameter, which are also connected to the tubular system of endoplasmic reticulum. The ampullae are surrounded by a bundle of fibrils that may have a role in contraction of the ampullae. The ampullae contract thereby, filling the vacuole and when the contents of the vacuole are discharged to the exterior the ampulae get disconnected so that back flow is prevented.

2370_Contractile vacuole - Protozoans.png

Figure: The contractile vacuole of Amoeba proteus is surrounded by tiny vesicles that fill with fluid, which is then, emptied into the vacuole. Note the numerous mitochondria that are believed to provide energy needed to adjust' the salt - content of the tiny vesicles.

Posted Date: 1/12/2013 6:06:05 AM | Location : United States







Related Discussions:- Contractile vacuole - protozoans, Assignment Help, Ask Question on Contractile vacuole - protozoans, Get Answer, Expert's Help, Contractile vacuole - protozoans Discussions

Write discussion on Contractile vacuole - protozoans
Your posts are moderated
Related Questions
5 beneficial effects of decomposers and 2 harmful effects

Q. Describe Coronary Spasm? Usually spasm develops at the site of subcritical or critical stenoses, but it may also occur in angiographically normal coronary arteries, the so c

What is adaptive radiation? Adaptive radiation happens when a new population in a new environment, like an island, undergoes divergent evolution until the descendant population

how to explain an example from each class of vertebrate

Factors affects oxygen dissociation curve - Carbon dioxide Carbon dioxide lowers the oxygen affinity of haemoglobin even if the pH is kept constant. This effect is due to the

What are the typical vegetation and the typical fauna of the tundra? Tundra has vegetation formed mainly by mosses and lichens. In the fauna the densely furred animals, like ca

Q. How do the muscles of the legs and of the feet contribute to the venous return? The muscles of the legs mainly the muscles of the calves compress and contract the deep veins

Electrophoresis is the technique of separating the large molecules (for instance DNA fragments or proteins) from the mixture of identical molecules. An electric current is passed

Determine the different types of sensory receptors There are different types of sensory receptors as follows:  Visual receptors in the eyes for vision.  Auditory receptor

Q. What is the vena cava? Which type of blood circulates within the vena cava? The vena cava is either of two large veins that debouch into the right atrium the superior vena c