Centrioles, Biology

Assignment Help:

Centrioles

  • Centrioles is also called cell centre.
  • Centrosome discovered by Benden. T. Boveri called it centrosome.
  • Centrosome is present in all animal eukaryotic cells but absent in higher plants.
  • H. Fol discovered spindle fibres.
  • Two centrioles located just outside nucleus, lie at right angle to each other.
  • Surrounding cytoplasm is clear called "Centrosphere" or "Kinoplasm".
  • Centrioles + centrosphere = Centrosome or Microcentrum or Diplosome.
  • Due to clear and shining centrosphere, centrioles are previously thought as light artifact. One end of centriole is open and other end is closed.
  • Centrioles are membraneless elongated structure.
  • Centrioles exhibit "Cart Wheel Structure" (Just like Basal body of Cilia). Basal body is also a type of centriole.

 

1208_centrioles.png

  • Each centriole consists of 9 peripheral microtubules and each microtubule made up of three sub tubules which are called A, B and C. So centriole is made up of peripheral triplet.
  • Each subtubule is made up of 13 protofilaments.
  • Each protofilament is a dimer of a and b tubulin protein.
  • Microtubules of centriole are made up of tubulin protein.
  • Central microtubules are completely absent in centriole but in central part Hub protein is present.
  • Each peripheral microtubule connects with hub protein with the help of radial spoke.
  • Terminal end of radial spoke (towards peripheri) forms a dense structure called X-body, which is present near the A-subtubule.
  • Between two X bodies, a Y-body is also present.
  • Each Y-body connected to X-bodies on its both sides.
  • A-C linker connects C- sub tubule of a microtubules with A-subtubule of another microtubule.
  • Randell and Disprey discovered DNA in centriole, which is called centriolar DNA. It has not been isolated till now but its presence is confirmed. Centriolar DNA is probably circular, naked and double stranded. Centriolar DNA helps in duplication of centriole during G phase of cell division but recently it is beleived that Massules or Pericentriolar Satellites help in duplication of centriole.
  • Around each peripheral microtubule a spherical structure is present, which is called Pericentriolar Satellites or Massules. These are 9 in number.
  • Centrioles are self duplicating units, contain DNA and RNA and are capable of protein synthesis.

Related Discussions:- Centrioles

Evaluate what is the frequency of carriers in a tank, Zebrafish are raised ...

Zebrafish are raised in fish tanks with one family per tank. The mutation spadetail is a recessive lethal. A stock tank for spadetail was made by crossing two carriers. The fish in

Results-types of surgery in ar, Results: Largely depends on the LV functi...

Results: Largely depends on the LV function. In most centres surgical mortality is 3 to 4 percent. For patients with severe LV dysfunction the immediate and late results of sur

Respiration, comparitive chart on different types of respiration obserbed i...

comparitive chart on different types of respiration obserbed in different type of respiration organ of respiration , types of respiration,energy obtained , by product formed

Cell - basic unit of life, Cell - Cell is the structural & functiona...

Cell - Cell is the structural & functional unit of life. Study of the structure of the cell is called cytology. Study of structure and functions of the cell is called

Explain nutritional support management - cancer patient, Explain about the ...

Explain about the Nutritional Support Management? Tube feeding is usually started. If tube feeding is not possible, parenteral nutrition through peripheral vein or through the

Explain the safe requirement of nutritional needs, Explain the Safe Require...

Explain the Safe Requirement of nutritional needs? Given the individual variations in nutritional requirements that have been discussed earlier, the lowest continuing intake le

Explain a renewable exhaustible natural resource, A renewable exhaustible n...

A renewable exhaustible natural resource is: 1. Coal 2. Petroleum 3. Minerals 4. Forest Forest is a renewable exhaustible natural resource

Slow moving waters - biota of rivers, Slow Moving Waters - Biota of Rivers ...

Slow Moving Waters - Biota of Rivers The habitat of a slowly moving part of the river is very different from the one just described. Here the water flow is comparatively slow

What is S shaped incision, Q. What is S shaped incision? The S - shaped...

Q. What is S shaped incision? The S - shaped incision is indicated where a papilla needs to be developed and was first described by Palacci. This type of incision is essentiall

Biota of the neritic oceanic zone, Biota of the Neritic Oceanic Zone T...

Biota of the Neritic Oceanic Zone This zone constitutes 75 per cent of the total oceanic area and is relatively rich in species and high in productivity owing to factors such

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