CENTRIOLE AND THEIR FUNCTION

CENTRIOLES

DEFINITION;

ANIMALS AND MANY UNICELLULAR ORGANISMS HAVE HOLLOW 

AND CYLINDRICAL ORGANELLES KNOWN AS CENTRIOLES.

LOCATION;

 ANIMALS CELLS, AND CELLS OF SOME MICROORGANISMS AND

 LOWER PLANTS CONTAIN TWO CENTRIOLES LOCATED NEAR THE

 EXTERIOR SURFACE OF THE NUCLEUS. 

CONSIST OF;

IN CROSS SECTION EACH CENTRIOLE CONSISTS OF A CYLINDRICAL

ARRAY OF NINE MICROTUBULES .

HOWEVER, EACH OF THE NINE MICROTUBULES IS FURTHER COMPOSED

 OF THREE TUBULES.

PLACED ON;

 THE TWO CENTRIOLES  ARE USUALLY PLACED AT RIGHT ANGLE TO

 EACH OTHER.  

WORKING;

JUST BEFORE A CELL DIVIDES, ITS CENTRIOLES DUPLICATE AND ONE

 PAIR MIGRATES TO THE OPPOSITE SIDE OF THE NUCLEUS. THE SPINDLE 

THEN FORMS BETWEEN THEM. THEY ARE ABSENT IN HIGHER PLANTS.

FUNCTION;

 CENTRIOLES PLAY IMPORTANT ROLE IN THE FORMATION OF CILIA

 AND FLAGELLA.

THE END