TYPES OF PARMANENT TISSUE BIOLOGY CLASS 9-TH NCERT CRITERIA

                        TYPES OF PERMANENT TISSUE 

SIMPLE TISSUE: THESE CELLS ARE PROTECTIVE AND SUPPORTIVE. THIS TYPE OF TISSUE IS COMPOSED ONLY ONE TYPE OF CELL.IT HAS VARIOUS TYPES THE THREE MAIN ARE DETAILED BELOW

1. PARENCHYMA: THESE CELLS ARE LIVING AND PROVIDES FOR CELL DIVISION , THEY ARE ROUND OR ISODIAMETRIC. ITS CELL WALL IS THIN AND AND ENCLOSES DENSE CYTOPLASM IN OTHER WORDS WE CAN SAY THAT IT HAS A LIVING PROTOPLASM .IT FUNCTION IS BASICALLY TO STORE FOOD AND OTHER NUTRIENTS.IT ALSO PLAY AN IMPORTANT ROLE IN TRANSFERRING THESE NUTRIENTS TO OTHER CELLS.IT ALSO STORES WASTE PRODUCTS OF A PLANT.

2.COLLENCHYMA: IT IS ALSO COMPOSED OF LIVING CELLS. IN THIS TYPE OF TISSUE CELLULOSE IS PRESENT AT CORNERS OF THE CELLS THAT WHY THESE CELLS ARE FLEXIBLE. HERE WE CAN DO AN EXPERIMENT BY WHICH WE CAN UNDERSTAND IT TREMENDOUSLY , TAKE A MOISTURE-R STICK BEND IT IF DO AS YOU CAN THAT WILL ONLY BEND NOT BREAK INSTEAD IF YOU WILL TAKE A DRY STICK THAT WILL ALSO GET BREAK. 

3. SCLERENCHYMA: SCLERENCHYMA CELLS ARE DEAD AND THEY ARE DEVOID OF CYTOPLASM. THE WALLS OF SCLERENCHYMA ARE GREATLY THICKENED WITH DEPOSITION OF LEGNIN. SUCH CELL WALLS ARE CALLED LEGNIFIED. CELLS OF SCLERENCHYMA ARE OF TWO TYPES SCLEREIDS AND FIBRES. FIBRES ARE LONG NARROW THICK AND LEGNIFIED  CELLS. THE LENGTH OF SCLERENCHYMA ARE OF DIFFERENT SIZES THEY VARY THIER SIZES FROM PLANT TO PLANT. SCLEREIDS ARE ALSO CALLED AS GRIT CELLS ,OFTEN THIN WALLS ARE PRESENT IN BOTH FIBRES AND SCLEREIDS CALLED AS PITS.