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

Diffrence between gymnosperms and bryophytes, Q. How different are gymnospe...

Q. How different are gymnosperms from pteridophytes and bryophytes? Gymnosperms are not cryptogamic as pteridophytes and bryophytes are. They are phanerogamic and so they form

Death, DE A T H - It is terminal end of the degeneration changes of ...

DE A T H - It is terminal end of the degeneration changes of old age. Death occurs when vescular system & respiratory system stop working. Failure of nervous system ma

Pattern of cleavage, define the pattern of cleavage i all aspects

define the pattern of cleavage i all aspects

Explain about picaridin, Picaridin Laboratory and field studies docume...

Picaridin Laboratory and field studies documenting the efficacy of picaridin. No published data are available on the efficacy of the 7% solution now available in the US. Insec

Plant classification according to ancient greeks and romans, Q. Plant class...

Q. Plant classification according to Ancient Greeks and Romans? Hippocrates, "The Father of Medicine" (460-377 B.C.) is reputed to have been one of Democritus 's disciples. He

Respiratory care on admission of patient, Respiratory Care on Admission (Fi...

Respiratory Care on Admission (First two hours) Patient is incubated and ventilator-dependent.  Monitor blood gases hourly and take corrective action immediately.

Explain heterologous and homologous immunoglobulins, Q. What is the differe...

Q. What is the difference between heterologous and homologous immunoglobulins? Homologous immunoglobulin is the human from the same species immunoglobulin and In case of inocul

Agro industrial-factors affecting vitamin utilization, Factors affecting vi...

Factors affecting vitamin utilization Raw soybean contains enzyme lipoxygenase which can be destroyed by heating for 5 min with steam at atmospheric pressure. Lipoxygenase cata

Explain the food applications of locust bean gum, Food Applications of Locu...

Food Applications of Locust bean gum Locust bean gum has multiple applications in food industry.  Let us focus on a few of the important ones: Locust bean gum has been u

What is diagnosis of heart disease in the newborn, What is Diagnosis of Hea...

What is Diagnosis of Heart Disease in the Newborn ? Clinical diagnosis of heart disease in the newborn can be quite challenging. Manifestations of potentially life threatening

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