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

Viral diseases, How do measles and HIV virus affects the bodies organisms

How do measles and HIV virus affects the bodies organisms

What is sodium-potassium pump, Sodium-potassium pump A. The net flux of...

Sodium-potassium pump A. The net flux of sodium is from a region of high sodium concentration to a region of low sodium concentration. B. The net flux of potassium is from a

What are cnidocytes, What are cnidocytes? What is the name of the capsule i...

What are cnidocytes? What is the name of the capsule inside the cnidocyte? What are the biological functions of this structure? Cnidocytes are specialized cells present in coel

Write two functions of proteins in biological system, Write two functions o...

Write two functions of proteins in biological systems. The important functions of proteins in biological systems are as follows: enzymes membrane carriers anti

What are some evolutionary advantages of animals, What are some evolutionar...

What are some evolutionary advantages of animals with complete digestive tube? The complete digestive tube permits animals to continuously feed themselves without waiting for r

Define disadvantages of using the plate counts method, Define Disadvantages...

Define Disadvantages of Using the Plate Counts Method? 1. It takes time, usually 24 hours or more is required to obtain visible colonies. 2. Microbial count obtained depends

Freeze fracture electron microscopy, Freeze Fracture Electron Microscopy ...

Freeze Fracture Electron Microscopy Freeze fracture electron microscopy i a technique lo reveal the surface features of hydrophobic interior of cell membrane. In this technique,

Why this stain have an affinity, Giemsa stain is a basic stain, thus the ma...

Giemsa stain is a basic stain, thus the major chromagen is positively charged (cation). Why does this stain have an affinity for the bacteria cell wall, and for certain cellular co

What are the three main signs of diabetes, What are the three main signs of...

What are the three main signs of diabetes? The three main signs of diabetes mellitus are called as the diabetic triad: polyuria, polydipsia and polyphagia. Polyuria is the e

Explain the drug effects on absorption of nutrients, Explain the Drug Effec...

Explain the Drug Effects on Absorption of Nutrients? Many drugs can impair, prevent or reduce absorption of nutrients due to: Formation of insoluble complexes: many drugs

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