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

Define the axon of a neuron, Consider an axon of a neuron. At time=t1, its ...

Consider an axon of a neuron. At time=t1, its voltage is at threshold for an action potential; at time=t2, its voltage is at 0 millivolts prior to the peak of that action potential

Why the orange trees are often sprayed with water, Why the orange trees are...

Why the orange trees are often sprayed with water? Although it is grossly counter-intuitive, whenever citrus groves are in risk of experiencing below-freezing temperatures, the

Pattern of growth, P A TTERN OF GROWTH - 1 .       ISOMETRIC - ...

P A TTERN OF GROWTH - 1 .       ISOMETRIC - In it an organ grows at the same rate as the rest of body. External form of body is not changed. eg. fish, locust. 2 .

Cell membrane lining the inner surface of the cell wall, Cell membrane lini...

Cell membrane lining the inner surface of the cell wall The cell membrane lining the inner surface of the cell wall is made up of phospholipids (45%) and proteins (55%). Some

Give the introduction to congenital heart disease, Give the introduction to...

Give the introduction to Congenital Heart Disease ? The past 3 or 4 decades have witnessed a revolution in pediatric cardiac sciences. A number of conditions previously conside

Describe cutaneous diffusion, Q. In arthropods why isn't gas exchange done ...

Q. In arthropods why isn't gas exchange done through cutaneous diffusion? In arthropods the impermeability of the exoskeleton makes the way of gases difficult. In addition the

Explain pseudocoelomates in classification animal kingdom, Explain Pseudoco...

Explain Pseudocoelomates in classification animal kingdom? In terms of body organization, Pseudocoelomates fall between the Acoelomates and the Coelomates. The body cavity in

Nerve cell - the basic unit, Nerve Cell - The Basic Unit The basic un...

Nerve Cell - The Basic Unit The basic unit of the nervous system is the nerve cell or neuron. A neuron is to the nervous system what a brick is to the building. It has a cell

Elaboration of yolk- reproduction, Normal 0 false false fal...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Describe the blood sugar testing, A small drop of blood is required to perf...

A small drop of blood is required to perform the test and this can be easily obtained from the patient's fingertip. A large number of glucometer devices are easily available and t

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