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 the determination of completion of reaction, Define the Determinatio...

Define the Determination of Completion of Reaction ? Several methods are used to determine when the reaction is complete. Some of these include (a) Observing an indicator (c

Excretion in roundworm, EXCRETIO N IN ROUNDWORM - In ascaris 4 coelomo...

EXCRETIO N IN ROUNDWORM - In ascaris 4 coelomoducts present, attached to each other by canaliculli in front of controling cell i.e. Rennete cell. Excretion materials are gi

Mitosis, What is the role of mitosis in growth?

What is the role of mitosis in growth?

Formation of aqueous humour, Formation of Aqueous  Humour It  is  unive...

Formation of Aqueous  Humour It  is  universally accepted that the aqueous  is  produced  by  the  ciliary processes. Although a great deal of  research has been done on the fo

Can you explain vestibular system, Q. What is the vestibular system? How do...

Q. What is the vestibular system? How does it operate? The vestibular system is the part of the ear that participates in the regulation and control of the equilibrium of the bo

Cells, what are golgi apparatus

what are golgi apparatus

What do you mean by platyhelminth phylum, Q What are the most tremendous kn...

Q What are the most tremendous known representatives of the platyhelminth phylum? The most popular representatives of the platyhelminthes are worms that cause human diseases, l

Explain future challenges of connecting models and data, Explain Future cha...

Explain Future challenges of connecting models and data? Since biological systems are complex, models of biological systems are also complex, and matching models and data is a

Investigation of aortic regurgitation by chest x–ray, Q. Investigation of a...

Q. Investigation of aortic regurgitation by Chest X–Ray? Left ventricular dilatation produces cardiomegaly on chest radiograph. Ascending aorta is often prominent. Egg shell ca

Determine the placental mammalian embryos, Which is the extraembryonic memb...

Which is the extraembryonic membrane whose function is to store nitrogen wastes of the embryo? Is this function present in placental mammalian embryos? The allantois is the ext

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