Contractile vacuole - protozoans, Biology

Assignment Help:

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.


Related Discussions:- Contractile vacuole - protozoans

Why is a man’s voice usually lower than a woman’s voice, Q. Why is a man’s ...

Q. Why is a man’s voice usually lower than a woman’s voice? Pitch of the voice-how low or high it sounds-it depends on the length, tension and thickness of the vocal cords. As

Causes of non-ketotic hyperosmolar diabetic coma, Q. Causes of Non-Ketotic ...

Q. Causes of Non-Ketotic Hyperosmolar Diabetic Coma? The causes of NKHDC are given below: 1) Infections 2) Trauma 3) Burns 4) Myocardial Infarctions (heart attack)

Explain pedicellaria in brief, Explain Pedicellaria in brief? Defensive...

Explain Pedicellaria in brief? Defensive pincerlike structures found on the surface of echinoderms. They are capable of responding to external stimuli independently from the ma

Pyramid of numbers - ecological pyramids, Pyramid of Numbers - Ecological P...

Pyramid of Numbers - Ecological Pyramids A graphic representation of the total number of individuals of different species belonging to each trophic level in an ecosystem is kn

Define nutritional requirements for young and older children, Define Nutrit...

Define Nutritional requirements for Young and Older Children? Young children need 3 en%, which would be easily met from 8-10 g of oil. However, more visible oil is needed to im

Advantages of vegetative propagation, Advantages of vegetative propagation ...

Advantages of vegetative propagation Vegetative propagation helps to maintain fixed qualities and characteristic features of the parent plant. For Example in ornamental p

Explain the term microfilaments, Explain the term Microfilaments ? Mi...

Explain the term Microfilaments ? Microfilaments are fine fibrils, only 7 nm in diameter, composed of a protein called actin. Actin is one of the two major proteins involved

What is the meaning of paraplegia, What is the meaning of Paraplegia Pa...

What is the meaning of Paraplegia Paraplegia (from the Greek para, "alongside of," and plegia,  "stroke") is a condition in which both lower limbs are paralyzed (quadriplegia i

Subdivisions of ecology, Subdivisions of Ecology Ecology was earlier di...

Subdivisions of Ecology Ecology was earlier divided into plant and animal ecology. However, modem ecology does not make any such distinction since plants and animals are intima

Does the trend of the change in shape of the graph, Does the trend of the c...

Does the trend of the change in shape of the graph as temperature increases differ when a different gas is examined?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd