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

Factors that affects oxygen dissociation curve - temperature, Factors that ...

Factors that affects Oxygen Dissociation Curves - Temperature At higher temperature haemoglobin gives up oxygen more readily and the dissociation curve shifts to the right. Th

Bile salts, BIL E SALTS These are sodium or potassium taurocholate ...

BIL E SALTS These are sodium or potassium taurocholate & glycolate. Lethocholic acid, cholic acid, deoxycholic acid & taurocholic acids are found in bile. Helps in em

Mounting boxes for insect collections, Mounting boxes for insect collection...

Mounting boxes for insect collections Wood or cardboard cigar boxes make very useful and suitable housings for insect collections. After the insect has been separate from the s

Detection of pulmonary hypertension, Pressure calculation made using the Be...

Pressure calculation made using the Bernoulli equation may be used  in conjunction with pressure measurements made by other modalities to determine various intracardiac pressure.

Handling microorganisms, Handling : You can reduce direct contact with mic...

Handling : You can reduce direct contact with microorganisms by careful handling and by wearing protective clothing such as rubber gloves, mask, lab coat, etc. Even if you entirel

The mechanism that ensures mendels first law, What is the mechanism that en...

What is the mechanism that ensures Mendel's First Law of segregation?

Explain about the nutritional requirements, Explain about the Nutritional R...

Explain about the Nutritional Requirements? Nutritional requirements are defined as 'intake levels of nutrients that meet specified criteria of adequacy such as normal growth,

What is h shaped incision and what is its purpose, Q. What is H shaped inci...

Q. What is H shaped incision and what is it's purpose? This type of incision is especially useful for: The anterior maxilla or mandible. Accurately identified implant

What is the cell theory, Q. What is the cell theory? Cell theory assert...

Q. What is the cell theory? Cell theory asserts that the cell is the element unit of living beings. Before the discovery of the cell, it was not acknowledged that living bei

Explain about listeria monocytogenes infection, Explain about Listeria mono...

Explain about Listeria monocytogenes infection Listeria monocytogenes is a gram-positive, motile, non-spore forming rod. It is widely distributed in nature and can be found on

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