Ciliated protozoan, Biology

Assignment Help:

Ciliated Protozoan

Ciliates form the largest and the most homogenous group of protozoans. They are placed under one phylum Ciliophora and evidence indicates that its members share a common evolutionary history. There are more than 7200 species found in fresh and marine waters and the water film of soil. About one third of ciliates are ecto and endoparasites or commensals. The classic example of this phylum is the slipper shaped Paramecium. Other well known examples are Vorticella, Stentor, Didinium, Balantidium.

317_Ciliated Protozoan.png

Figure: Various ciliates. Vorlieella and Stentor sessile ciliates, Stentor can also release itself and swim about. Didinium a raptoral ciliate Tetrahymena, Acineta with bunches of tentacles.


All ciliates possess cilia for locomotion and for suspension feeding. Another (Organization) distinguishing feature is the presence of kinetosomes (ciliary basal body) and an associated complex anchorage system of fibrils connecting the kinetosomes in longitudinal rows. All of these make the subsurface ciliature or infraciliary system. Most ciliates have a mouth or cytostome and feed by sweeping particle laden water into the mouth. The cytostome and cytopharynx open into the food vacuole and undigested remains are expelled through a fixed spot. Another characteristic feature is the presence of 2 types of nuclei. One large macronucleus and one or more small micronuclei. The macronucleus is called the vegetative nucleus as it regulates the normal metabolic processes of the organism for mitotic division and for control of cellular differentiation.

It is required for protein synthesis. The amount of DNA that macronucleus contains is much more than what is present in micronucleus because of duplications following the formation of macronucleus from the micronucleus. The micronucleus on the other hand is small and rounded. It is diploid and more than one may be present, with little RNA. The micronucleus contains the genetic material responsible for genetic exchange during sexual reproduction and also for reforming the macronucleus. Ciliates reproduce asexually by transverse fission and sexually through conjugation which involves the exchange and fusion of micronuclei at the region of contact.


Related Discussions:- Ciliated protozoan

Periphyton - aquatic ecosystem, Periphyton - Aquatic Ecosystem These a...

Periphyton - Aquatic Ecosystem These are organisms which remain attached or clinging to stems and leaves of rooted plants or substances emerging above the bottom mud. Usually

Precautions used during a fever in a human, During a fever in a human  ...

During a fever in a human   A.  shivering may occur when the actual body temperature is lower than the set point for body temperature during the fever.   B.  there is an inc

Define commodity topics of food science, Define Commodity Topics of Food Sc...

Define Commodity Topics of Food Science? All issues of food science and technology of certain commodity groups, including milk and milk products (fluid milk and derivatives, ic

Explain the surgical management for obesity, Explain the Surgical Managemen...

Explain the Surgical Management for Obesity? Surgical procedures are generally restricted for the morbidly obese persons. If an individual has a BMI of 40 or higher, or a BMI o

Heat production, Heat Production In the Homeotherms heat production m...

Heat Production In the Homeotherms heat production must be elevated if the ambient temperature falls below the critical temperature. Although all metabolic processes result i

What are the main degenerative diseases of the heart, Q. What are the main ...

Q. What are the main degenerative diseases of the heart? The major degenerative diseases of the heart are heart failure, arrhythmias, valvular heart diseases, coronary insuffic

Describe the importance of neuropsychological tests, Describe the importanc...

Describe the importance of Neuropsychological tests Neuropsychological tests are generally thought of as assessment instrument for a variety of cognitive, perceptual, and motor

Body fluids – circulation, Normal 0 false false false E...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Explain the factors affecting gi of foods, Explain the Factors Affecting GI...

Explain the Factors Affecting GI of Foods? A variety of factors affect GI of foods. The factors which affect the rate of glucose absorption from starchy foods and therefore the

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