Cilia and flagella, Biology

Assignment Help:

CILIA AND FLAGELLA

  • Purkinje first observed ciliary movement.
  • Hodge studied detail structure of sperm flagellum.
  • Manton studied structure of cilia in plants.
  • Cilia and flagella are simillar in structure. There are some external differences between cilia and flagella.

Cilia

Flagella

Shorter - 5 to 1 0 m in length

 

More in number on a cell

(14000/cell)

 

Exhibit sweeping or pendular movement.

It includes power stroke and recovery stroke.

Action co-ordinated

upto 150 m long

 

Few in number

(1-8/cell)

 

undulating movement

 

Action not co-ordinated

  • Both structures help in locomotion, excretion, secretion and transportation.
  • Cilia and flagella are present in eukaryotic cells except slime moules.
  • Cilia and flagella are also present in prokaryotic cells except Anabena (BGA).
  • Cilia and flagella shows 9+2 arrangement of microtubules.
  • Cilia and flagella consists of 3 parts -

(1) Basal body                 (2) Basal Plate               (3) Shaft

(1) Basal body

  • It is also known as kinetosome or basal granule or blepheroplast.
  • It has 9+0 orientation of microtubule.
  • Hub protein present in the proximal part of basal body but absent in distal part.
  • Central part of basal granule is composed of semisolid cytoplasm called "Central Hub". Microtubules connected to central Hub with the help of protein fibres called primary fibres. Secondary fibres connect microtubules with each other. The triplet microtubules form an angle of 40° with the tangent of basal granule.
  • Rootlet - A conical bundle of protein fibers arise from basal body, Rootlet have dark bands composed of ATPase.
  • Synthesis of ATP takes place in dark bands.

(2) Basal Plate

  • Present between basal body and shaft.
  • It conects basal body and shaft to each other.
  • Two major changes occur at the region of basal plate -

(i) Triplet of peripheral microtubule convert into doublet of microtubules. (ii) Central microtubules develop from distal end of Hub protein.

(3) Shaft

Shaft consists of two parts -

(i) Sheath

(ii)  Axoneme

  • Outer covering of cilium or flagellum is called sheath. Peripheral sheath covers peripheral microtubule whereas central sheet covers central microtubules.
  • Axoneme of shaft consists of 11 microtubules (9 peripheral and 2 central).

738_cilia and flagella.png

  • Axoneme shows 9+2 arrangement of microtubules.
  • Each peripheral microtubule consists of A and B subtubule.
  • A subtuble has two bent arms, these are made up of dyenine proteins. These arms directed in clockwise fashion. Arms of A-tubules composed of an enzymatic protein. Dynien similar to myosin of muscles. Dynien protein have ability to split A TP ( in presence of Ca+ 2 and Mg+2) and liberate energy for movement. Cilia and flagella bend or move due to sliding of microtubules along one another while maintaining their individual length (mechanism simillar to muscle contraction).
  • Each peripheral microtubules consists of tubulin protein. Tubulin simillar to Actin protein of muscles.
  • A and B subtubules connected to each other with the help of Nexine protein.
  • Both central microtubules connected to each other with protoplasmic bridge. Central sheath is present around the central microtubule.
  • Each A subtubule liked to central sheath with the help of radial spoke. Terminal end of radial spoke forms knob like structure that is known as spoke head. Spoke head is present near to central sheath.
  • Transition junctions are also present between central sheath and spoke head.
  • Shaft of cilium of flagellum filled with proteinacious matrix.

Related Discussions:- Cilia and flagella

Raw material for industry - impacts on biodiversity, Raw Material for Indus...

Raw Material for Industry - impacts on biodiversity The industry, producing goods and services, relies and impacts on biodiversity directly. Much of the raw material that goes

Explain about the celiac disease, Explain about the Celiac Disease? Cel...

Explain about the Celiac Disease? Celiac disease (also called gluten enteropathy) is an intestinal disorder that results from an abnormal  immunological reaction to gluten. u p

Obtain half their genes from one parent, If children obtain half their gene...

If children obtain half their genes from one parent and half from the other parent, why aren't siblings identical?

Phylum protozoa, What is the classification of this phylum

What is the classification of this phylum

Observation of bumpus, An interesting observation made by an American biolo...

An interesting observation made by an American biologist H.C. Bumpus (1899) provides a good explanation for normalising selection. Bumpus collected some 136 injured house sparrows

Dietary recommendations proposed by whom, Q. Dietary recommendations propos...

Q. Dietary recommendations proposed by WHOM? We learnt about their etiological factors, metabolic alterations, clinical anifestations and dietary management of the disease of h

Describe about postural changes in dynamic auscultation, Describe about Pos...

Describe about Postural Changes in Dynamic Auscultation? a) On sudden assumption of supine position from standing on sitting position or sudden passive elevation of both legs:

How to follow a cell through the cell cycle, Follow a cell through the cell...

Follow a cell through the cell cycle. How many copies of each gene are present at each stage?

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