cell wall and nucleus

1. THE FUNDAMENTAL
UNIT OF LIFE
PART -3
BY : MISS RITIMA

2. CELL WALL
PRESENT IN PLANT CELL , LIES
OUTSIDE PLASMA MEMBRANE.
IT IS COMPOSED OF CELLULOSE. IT
IS THE COMPLEX SUBSTANCE AND
PROVIDE STRUCTURAL STRENGTH
TO THE PLANT.
WHEN LIVING PLANT CELL LOSES
WATER THROUGH OSMOSIS THERE
IS THE SHRINKAGE OR
CONTRACTION OF CONTENT OF
CELL AWAY FROM THE CELL WALL .
THIS PHENOMENON IS CALLED
PLASMOLYSIS.

3. PLASMOLYSED PLANT CELL
PROTOPLASM WHICH IS THE LIVING
MATTER OF THE CELL IT GETS
SHRINKED ON PLASMOLYSES.

4. FUNCTIONS
CELL WALL PROVIDE SHAPE TO THE
CELL.
IT PROVIDES THE MECHANICAL
STRENGTH.
IT PROTECTS THE CELL AGAINST
PATHOGENS AND MECHANICAL
INJURY.
BECAUSE OF CELL WALL PLANT
CELL CAN WITH STAND A LOT OF
VARIATION IN THE SURROUDING
MEDIUM AS COMPARED TO ANIMAL
CELL.

5. NUCLEUS
 THE NUCLEUS IS CALLED DIRECTOR
OF CELL BECAUSE IT CONTROLS
THE CELL‘S ACTIVITY.
 NUCLEUS HAS DOUBLE LAYER
MEMBRANE CALLED AS NUCLEAR
MEMBRANE.
 THE NUCLEUS CONTAIN
CHROMOSOMES .
 CHROMOSOMES ARE COMPOSED
OF DNA AND PROTEINS

6. STRUCTURE OF NUCLEUS

7. BASIC CONCEPT
NUCLEAR ENVELOPE: IT THE DOUBLE
MEMBRANE COVERING THAT
SEPARATES NUCLEUS FROM THE
CYTOPLAM.
NUCLEOPLASM: IT IS THE
COLOURLESS , DENSE SAP FOUND
INSIDE THE NUCLEUS IN WHICH
CHROMOSOMES AND NUCLEOLUS IS
SUSPENDED.
NUCLEOLUS: ROUND STRUCTURE
INSIDE THE NUCLEOUS. RICH IN RNA
AND PROTEIN AND SITE OF RIBOSOME
FORMATION.

8. .
 .

9. FUNCTIONS OF NUCLEUS
NUCLEUS CONTAINS ALL GENETIC
INFORMATION.
IT FUNCTION AS THE CONTROL CENTRE
OF THE CELL AND CONTROL ALL
METABOLISM OF THE CELL.
THE RIBOSEMES ARE FORMED BY
NUCLEOLUS PART OF THE CELL.
 RESHUFFLING OF CHROMOSOMES
CAUSES CHANGES IN GENES AND
PRODUCE VARIATIONS.

10. TRY TO ANSWER….
Q: What is osmosis?
Q: Where ribosomes are formed in
formed?
Q: write 3 functions of each :
a. cell wall
b. Nucleus
Q: Expand the terms:
a. DNA
b. RNA