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

Biodiverse ecosystems of economic application, Q. What are some economic ap...

Q. What are some economic applications that can be generated by very biodiverse ecosystems? Extremely biodiverse areas present huge economic potential and they can be a source

After the morula stage what is the next stage, Q. After the morula stage wh...

Q. After the morula stage what is the next stage? What is the morphological feature that defines this stage? In the blastula stage the compactness is lost and an internal cavit

What are histogenesis and organogenesis, What are histogenesis and organoge...

What are histogenesis and organogenesis? Histogenesis is the procedure of tissue formation in the embryonic development. Organogenesis is the process of organ formation. Before

Mechanism of gastrulation, MECHANISM OF GASTRULATION - It is most im...

MECHANISM OF GASTRULATION - It is most impotant stage of embryonal development, in which single layered blastula converts into 2 or 3 layered gastrula. During this stage,

What are neurons, Question 1 Give the definition and describe the mechanis...

Question 1 Give the definition and describe the mechanism of Active transport. Passive transport with suitable examples Question 2 What are neurons? List out the

Define the chromosome region, Q. How is the chromosome region where the cen...

Q. How is the chromosome region where the centromere is located called, and how chromosomes classified in the relation to the position of their centromere? The chromosome regio

What is carrier protein, How does the interaction between a carrier protein...

How does the interaction between a carrier protein and the substance it transports resemble the interaction among an enzyme and its substrate? Both include the binding of a spe

Explain adverse effects of voriconazole, Adverse Effects of voriconzole ...

Adverse Effects of voriconzole Transient visual disturbances, including blurred vision, photophobia and altered perception of color or image, are common with voriconazole. Rash

What is peristomium. describe, What is peristomium. Describe? The segme...

What is peristomium. Describe? The segment behind the prostomium in annelids which contains the oral opening. This segment like the prostomium isn't a true segment and has no s

Define growth and development of infants and preschoolers, Define Growth an...

Define Growth and Development of Infants and Preschoolers? In this unit, we learnt about the various aspects related to the growth and development of infants and preschoolers.

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