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

How is the body of gastropods divided, Q. How is the body of gastropods div...

Q. How is the body of gastropods divided? The body of gastropods is divided into three major portions: head, foot and the visceral mass. Q. What is the type of digestive sy

Learning objectives of metabolic diseases, Q. Learning objectives of metabo...

Q. Learning objectives of metabolic diseases? • enumerate the etiological factors and symptoms of gout and few inborn errors of metabolism, • describe the metabolic changes

Reviews - assurance engagements, Reviews - Assurance engagements The o...

Reviews - Assurance engagements The objective of financial statements of a review is to enable an auditor to state where, on the essential of procedures that do not give all t

Describe tranposition of great arteries intact ventricular, Describe tranpo...

Describe tranposition of great arteries with intact ventricular septum? Transposition of great arteries with intact ventricular septum (or small VSD): There is usually inadequa

Diet, heating a food sample with Benedict''s solution is a test for...

heating a food sample with Benedict''s solution is a test for...

What do you understand by abdomen, In organisms that have undergone tagmosi...

In organisms that have undergone tagmosisthe trunk often develops into two tagma, oneinvolved in locomotion and one that is notlocomotory. The tagma not involved in locomotionis re

Chambers of the heart, Chambers of the Heart The heart is divided in...

Chambers of the Heart The heart is divided into two halves by a muscular wall or septum, the right heart and the left heart. The function of the right heart is to collect

How will privacy and confidentiality of clinical data, Question 1: What...

Question 1: What are the requirements you need to satisfy for internet usage and remote data capture under 21 CFR parts 11 in a clinical trial? Define 21 CFR parts Me

Explain huntington disease gene, Research methods used in studying a geneti...

Research methods used in studying a genetic disease change with technological advances. These changes can be seen in Reading 22.1: Discovering the Huntington Disease Gene, which de

Define criteria for assessment of niacin status, Define Criteria for Assess...

Define Criteria for Assessment of Niacin Status? Niacin status can be monitored by daily urinary excretion of methylated metabolites, especially the ratio of the 2-pyridone to

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