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

Different types of stems, Different types of stems (a)  Monocots. Secur...

Different types of stems (a)  Monocots. Secure stems of various plants such as bamboo, sugar cane and corn. Cut every of the stems crosswise with a very sharp knife or razor bl

Deficiency diseases-parturient paresis , Parturient paresis (milk  fever, h...

Parturient paresis (milk  fever, hypocalcaemia) Parturient paresis is an acute to peracute non-febrile disease, which occurs in diary cows and buffaloes usually around the t

Positive and negative regulation, Normal 0 false false fals...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4 The lac operon is an

Differences between meiosis and mitosis, Q. Concerning their final products...

Q. Concerning their final products daughter cells and their ploidies what are the differences between meiosis and mitosis? In mitosis one cell for illustration with 2n chromoso

Explain what is correction of hypovolemia, Explain what is Correction of Hy...

Explain what is Correction of Hypovolemia ? Intravenous fluids should be given to correct hypovolemia and optimize preload to the heart. This is particularly important in sept

What is resting membrane potential of a neuron, What is resting membrane po...

What is resting membrane potential of a neuron? What is the function of sodium potassium pumps in maintaining it?

Cytology, Cytology: The study of form or culture including the behavior of ...

Cytology: The study of form or culture including the behavior of nucleus and other organelles is called cytology. Cytology means "the study of cells". Cytology is the branch of lif

In what ways does over-grazing lead to soil erosion, In what ways does over...

In what ways does over-grazing lead to soil erosion? Over-grazing leads to erosion because (i) the animals delete all the vegetation, so exposing the soil to heavy rain, (ii) t

What is inflammation, What is inflammation? Inflammation is the initial...

What is inflammation? Inflammation is the initial response of the unspecific defense system versus aggressions against the body (the aggressions might be caused by infectious p

What is autophagic intracellular digestion, What is autophagic intracellula...

What is autophagic intracellular digestion? Why is this type of intracellular digestion intensified in an organism undergoing starvation? Autophagic intracellular digestion is

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