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

Define effect of protein deficiency during pregnancy period, Define effect ...

Define effect of Protein deficiency during pregnancy period? The effects of protein deficiency during pregnancy are difficult to separate from the effects of caloric deficit, s

Is there such thing as good evaporation and bad evaporation, Hello I have b...

Hello I have been working with reptiles for a while and have been researching the incubation method known as egg suspended. This method is used with birds. Its placeing an egg on a

Taxonomy, how do i classify mythical creatures into a web?

how do i classify mythical creatures into a web?

Maturation promoting factor, • Cyclins accumulate during the G1, S, and G2 ...

• Cyclins accumulate during the G1, S, and G2 phases of the cell cycle. • By the G2 checkpoint (the red bar in the figure), enough Cyclin is available to form MPF complexes (aggre

Short note on glycogen storage diseases, Write short note on glycogen stora...

Write short note on glycogen storage diseases. Glycogen storage diseases are caused by genetic defects  that  result in deficiencies in certain enzymes of glycogen metabolism.

Human diseases caused by virus, Q. What are some human diseases caused by v...

Q. What are some human diseases caused by virus and what are their respective modes of transmission? The major viral diseases transmitted by respiratory secretions (cough, snee

Agro industrial-copper, Copper Copper is an essential trace element re...

Copper Copper is an essential trace element required for enzyme systems, iron metabolism, connective tissue metabolism, integrity of the central nervous and immune systems. Co

Define function of the iron uptake by cells, Define Function of the Iron Up...

Define Function of the Iron Uptake by Cells? Iron has several vital functions in the body. It serves as a carrier of oxygen to the tissues from the lungs by red blood cell haem

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