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

Acute bronchitis, Acute Bronchitis: Acute bronchitis is inflammation  ...

Acute Bronchitis: Acute bronchitis is inflammation  of one or more bronchi  and occurs specifically  in children younger than  four year?.  It is usually associated with previ

Explain about the management of food allergies, Normal 0 false ...

Normal 0 false false false EN-IN X-NONE X-NONE

How age factors affecting the calcium absorption, How Age factors Affecting...

How Age factors Affecting the calcium absorption? Age is another factor which influences the absorption of calcium. Fractional absorption of calcium is highest in infancy i.e.,

Biodynamic dealing with energetic of organisms, Biodynamic: This dealing w...

Biodynamic: This dealing with energetic of organisms. Biodynamic is a method of organic farming which treats farms as unified or individual organisms, emphasizing balancing the ho

Benthos - aquatic ecosystem, Benthos - Aquatic Ecosystem The benthos o...

Benthos - Aquatic Ecosystem The benthos or the benthic organisms are those found living in or on the bottom or benthic region of the water mass. They exhibit a variety of adap

Inclusion body hepatitis (ibh), I nclusion body hepatitis (IBH) A dise...

I nclusion body hepatitis (IBH) A disease of chickens characterized by acute mortality, often with severe anemia, is caused by an adenovirus. A number of different serotypes h

Conductometry, Highlight ten applications of conductometry and explain four...

Highlight ten applications of conductometry and explain four in detail

Development of psychiatric nursing in other countries, DEVELOPMENT OF PSYCH...

DEVELOPMENT OF PSYCHIATRIC NURSING IN OTHER COUNTRIES: Although the scientific findings rejected the belief that mental disturbance was the devil's work, the earliest asylums

Regulation of glycogenesis, Regulation  of Glycogenesis Glycogen syntha...

Regulation  of Glycogenesis Glycogen synthase,  the key enzyme in glycogenesis, is activated by insulin and glucose and inhibited by CAMP.

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