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

Use of masks as personal protective equipment, Q. Use of Masks as personal ...

Q. Use of Masks as personal protective equipment? Masks are to be worn when procedures that result in aerosol production are performed. Protection from these masks only affords

What is the genetic family tree, What is the genetic family tree? The G...

What is the genetic family tree? The Genetic family tree is a schematic family tree that shows the biological inheritance of some trait through successive generations. The G

Explain eicosanoids, Explain Eicosanoids Eicosanoids are the  local h...

Explain Eicosanoids Eicosanoids are the  local hormones formed  by  body  tissues during self-healing responses  to  stimuli.  Eicosanoids are  a family  of  compounds  deriv

Spirogyra, whats the meaning of asexual reproduction

whats the meaning of asexual reproduction

Which is not produced by the hypothalamus, Which of the following is NOT pr...

Which of the following is NOT produced by the hypothalamus? A) releasing hormones B) inhibiting hormones C) antidiuretic hormone D) oxytocin E) thyroid-stimulating h

How to create organisms with traits, Do a bit of research on gene splicing,...

Do a bit of research on gene splicing, a DNA technology that bioengineers can use to create organisms with traits that never before seen in nature (herbicide-resistant crops, mice

Mechanism of regeneration, MECHANISM OF REGENERATION - T.H. morgan reco...

MECHANISM OF REGENERATION - T.H. morgan recognised 2 primary mechanisms - M o r ph o l axis Epim orphosis 1. Production of enti

Explain aerobic cellular respiration during muscle exercise, What happens w...

What happens when the oxygen supply is insufficient to maintain aerobic cellular respiration during muscle exercise? If oxygen from hemoglobin or myoglobin is not enough for th

Which pancreatic tissues involved in endocrine secretion, Q. What are the p...

Q. What are the pancreatic tissues involved respectively in the endocrine and exocrine secretions? What are their respective hormones and enzymes? The exocrine secretion of the

Phylum labyrinthomorpha - protozoan, Phylum Labyrinthomorpha - Protozoan ...

Phylum Labyrinthomorpha - Protozoan Trophic stage, ectoplasmic network with spindle shaped or spherical nonamoeboid cells. Small group living on algae; mostly marine or estuar

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