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

Osmoregulation, explain osmoregulation in crustacean ?

explain osmoregulation in crustacean ?

Define the g1 phase during their cell cycle, What would happen to a cell an...

What would happen to a cell and its offspring if the cells did not go by a G1 phase during their cell cycle? Describe Without a G1 growth phase, the cells would not grow to th

Infectious coryza, I nfectious coryza A highly infectious bacterial di...

I nfectious coryza A highly infectious bacterial disease of chickens caused by Hemop hilus paragallinarum, is characterized by catarrhal inflammation of the upper respirator

Agro industrial-mineral supplements, Mineral supplements There are two...

Mineral supplements There are two major classes of mineral sources: inorganic and organic. Organic complexes, however, have been shown to be more effectively absorbed by the a

Brain region that triggers the voluntary motor activity, Which is the brain...

Which is the brain region that receives conscious sensory information? Which is the brain region that triggers the voluntary motor activity? In the brain conscious sensory info

Interpretation of blood or serum nutrient value in pregnancy, Define Interp...

Define Interpretation of blood or serum nutrient values in pregnancy? Interpretation of blood/serum nutrient values in pregnancy is therefore complex compared to the non-pregn

Before purchasing - nursing software, Before Purchasing  Ideally it...

Before Purchasing  Ideally it's wise to buy a readymade software with options to further customize it to suit your managerial functions.   A totally Custom-made softwar

Normality, what is the normality law?

what is the normality law?

Zoology, About phylum platy helmenthus

About phylum platy helmenthus

Etiology, Etiology The infectious agent of psittacosis - lymphogranuloma v...

Etiology The infectious agent of psittacosis - lymphogranuloma venerum trachoma group (PLVG) is an obligate intracellular parasite and is classified as separate genera with only 2

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