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

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

Homework, #questiocan you help in a biology question?.

#questiocan you help in a biology question?.

Enumerate the major substrates for gluconeogenesis, Enumerate the major sub...

Enumerate the major substrates for gluconeogenesis The major substrates for gluconeogenesis are the glucogenic amino acids, lactate  glycerol and (important  in ruminant) propi

Define major divisions & representing species of gymnosperm, What are the m...

What are the major divisions and representing species of the gymnosperms? This group of plants can be separated into conifers (pine, sequoia, cypress), that have flowers called

Define poverty alleviation to control under nutrition, Define Poverty Allev...

Define Poverty Alleviation to control under nutrition? There are a number of development programmes aiming at employment assurance to the landless and other labour with a focus

Methods including quantification of rna species, 1.   Northern blotting ...

1.   Northern blotting The quantity of rna species can be quantified by calculating the quantity of rna through northern blotting which provide size and sequence information

Radiographic imaging, R a d i o g raphic imaging: ...

R a d i o g raphic imaging: Radiology has been in use since the discovery of X-rays by Wilhelm Conrad Roentgen in 1895. Until 1980s, radiography was the

Determine requirement of carbohydrate for endurance events, Determine the R...

Determine the Requirement of carbohydrate for Endurance Events? For endurance events like sprinting (100 m run), football, hockey, the carbohydrate intake can be placed at 7:10

What is glycogen metabolism, Glycogen is a multibranched polysaccharide whi...

Glycogen is a multibranched polysaccharide which serves as a part of energy storage in fungi and animals. In humans the glycogen is recognized and stored primarily in the cells of

Phototropic curvature is the result of uneven distribution, Phototropic cur...

Phototropic curvature is the result of uneven distribution of : 1. Gibberellin 2. Phytochrome 3. Cytokinins 4. Auxin Auxin

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