PLANT TISSUES FOR CLASS 9 SUMMARY CBSE.pptx

THIS CHAPTER IS EXPLAINED IN SHORT AND BRIEFLY , FOR CLASS 9 CBSE , I HAVE PPT HAVING ONLY PLANT TISSUE AND NOT INCLUDED "ANIMAL TISSUE" . I HAVE MADE THIS PPT FOR LAST MINUTE REVISION FOR STUDENTS. THIS PPT CONTAINS SOURCE FROM NCERT TEXTBOOK .

1. TISSUES What is tissue? A group of cells which perform a specific function is called tissue. There are two types of plant tissue MERISTEMATIC PERMANENT TISSUE TISSUE

2. MERISTEMATIC TISSUE THIS TISSUE IS RESPONSIBLE FOR THE GROWTH OF THE PLANT . THERE ARE THREE TYPES OF MERISTEMATI TISSUE: APICAL MERISTEM LATERAL MERISTEM INTERCALARY MERISTEM APICAL MERISTEM IT IS PRESENT IN THE GROWING TIPS AND ROOTS OF THE STEM. IT INCREASES THE LENGTH OF THE STEM AND THE ROOT AND IT IS RESPONSIBLE FOR PRIMARY GROWTH . MADE OF ACTIVELY DIVIDING CELLS .

3. LATERAL MERISTEM THE GIRTH OF THE STEM OR ROOT INCREASES DUE TO LATERAL MERISTEM (CAMBIUM) . RESPONSIBLE FOR THE SECONDARY GROWTH . MADE UP OF ACTIVELY DIVIDING CELLS . INTERCALARY MERISTEM IT IS FOUND AT THE BASE OF LEAVES OR INTERNODE IN SOME PLANT. IT HELPS IN INCREASING THE LENGTH OF THE PLANT . HELPS IN REGROWTH OF PARTS THAT ARE CUT OR EATEN BY ANIMALS . CELLS ARE ACTIVELY DIVIDING .

4. PERMANENT TISSUE THIS TISSUE DOES NOT HAVE THE ABILITY TO DIVIDE . AFTER SOME TIME , MERISTEMATIC TISSUE GETS CONVERTED INTO PERMANENT TISSUE , IT PROCESS IS CALLED DIFFERENTIATION . THERE ARE TWO TYPES OF PERMANENT TISSUE : SIMPLE PERMANENT COMPLEX PERMANENT TISSUE TISSUE

5. SIMPLE PERMANENT TISSUE THERE ARE THREE TYPES OF SIMPLE PERMANENT TISSUE: PARENCHYMA COLLENCHYMA SCRENCHYMA

6. PARENCHYMA THIS TISSUE SUPPORT PLANTS AND STORE FOOD IN ROOTS AND STEMS . IT HAS LIVING CELLS . PARENCHYMA HAS THIN-WALLED . LOOSELY PACKED . THERE ARE TWO TYPE OF PARENCHYMA : CHLORENCHYMA AERENCHYMA

7. CHLORENCHYMA IT CONTAINS CHLOROPHYLL AND PERFORMS PHOTOSYNTHESIS. AERENCHYMA IN AQUATIC PLANTS , LARGE AIR , CAVITIES ARE PRESENT IN PARENCHYMA TO HELP THEM FLOAT. EXAMPLES : LOTUS .

8. COLLENCHYMA THEY PROVIDE FLEXIBILITY , ALLOWING LEAVES AND STEMS TO BEND WITHOUT BREAKING . IT HAS LIVING CELLS . IT HAS UNEVENLY THICKENED CELL WALLS . IT DOES NOT HAVE LIGNIN. SCLERENCHYMA THEIR ROLE IS TO PROVIDE HARDNESS AND STIFFNESS TO TREES . IT HAS DEAD CELLS . IT IS PRESENT ON THE HUSK OF THE COCONUT . THEY ARE LONG AND NARROW AS THE WALLS ARE THICKENED DUE TO LIGNIN .

9. EPIDERMIS THE OUTERMOST LAYER OF CELLS , ARE CALLED EPIDERMIS . EPIDERMIS IS USUALLY MADE UP OF A SINGLE LAYER OF CELLS . IN SOME PLANTS LIVING IN DRY HABITATS , THAT EPIDERMIS MAY BE THICKER SINCE PROTECTION OF WATER LOSS . IT PROTECTS ALL PARTS OF THE PLANTS . TRANSLOCATION : TRANSPORT OF FOOD . THE SMALL PORES WHICH ARE PRESENT IN EPIDERMIS ARE CALLED STOMATA . STOMATA ARE ENCLOSED BY TWO KIDNEY-SHAPED CELLS CALLED GUARD CELLS . STOMATA ARE NESSESARY FOR EXCHANGING OF GASES IN ATMOSPHERE .

10. EPIDERMIS IT ALSO PROTECTS PLANTS FROM INJURY , PATHOGENS AND WATERLOSS . IN SOME PLANTS LIKE DESERT PLANTS , EPIDERMIS HAS A THICK WAXY COATING OF CUTIN . CELLS OF CORK ARE DEAD AND COMPACTLY ARRANGED WITHOUT INTERCELLULAR SPACES . THEY ALSO HAVE A SUBSTANCE CALLED SUBERIN IN THEIR WALLS THAT MAKES THEM IMPERVIOUS TO GASES AND WATER .

11. COMPLEX PERMANENT TISSUE COMPLEX PERMANENT TISSUE ARE MADE OF MORE THAN ONE TYPE OF CELLS . THERE ARE TWO TYPES OF COMPLEX TISSUE : XYLEM PHLOEM

12. XYLEM IT IS RESPOSIBLE FOR THE TRANSPORTATION OF WATER AND MINERALS IN PLANTS . XYLEM CONSISTS OF TRACHEIDS , VESSELS , XYLEM FIBRE , XYLEM PARENCHYMA . XYLEM FIBRE IS MAINLY SUPPORTIVE IN FUNCTION . TRACHEIDS AND VESSELS ALLOWS THEM TO TRANSPORT WATER AND MINERALS . IN XYLEM , ALL CELLS ARE DEAD BUT ONLY XYLEM PARENCHYMA IS LIVING .

13. PHLOEM PHLOEM IS MADE UP OF FIVE TYPES OF CELLS : SIEVE CELLS , SIEVE TUBES , COMPANION CELLS , PHLOEM FIBRES AND PHLOEM PARENCHYMA . PHLOEM TRANSPORTS FOOD FROM LEAVES TO OTHER PARTS OF THE PLANT . IN PHLOEM , ALL CELLS ARE LIVING EXCEPT THE PHLOEM FIBRE .