SHOBHA ROLLNO. 14

FUNDAMENTAL UNIT OF LIFE

EXERCISE

      

Q1. MAKE A COMPARISON AND WRITE DOWN WAYS IN WHICH PLANT CELLS ARE DIFFERENT FROM ANIMALS CELLS?

ANS.       ANIMAL CELL                                                         PLANT CELL

• CELL WALL IS ABSENT                                          CELL WALL IS PRESENT
• PLASTIDS ARE ABSENT                                          PLASTIDSIS PRESENT  
• CENTROSOME WITH ONE OR                                CENTROSOME AND CENTRIOLES   

 TWO CENTRIOLES IS PRESENT                                       ARE ABSENT

• NUCLEUS LIES PERIPHERALLY                           NUCLEUS USUALLY LIES IN THE 

IN THE CYTOPLASM                                                          CENTRE

Q2. HOW IS PROARYOTIC CELL DIFFERENT FROM A EUKARYOTIC CELL?   

ANS.         PROKARYOTIC CELL                                  EUKARYOTIC CELL

             1. MEMBRANE BOUND ORGANEUES           1. MEMBRANE BOUND ORGANELLES 

                    ABSENT                                                               PRESENT

              2.SIZE OF THE CELL IS SMALL                      2. SIZE OF THE CELL IS LARGE  

               3. PRIMITIVE NUCLERS NOT                          3.THE NUCLEUS BOUNDED BY 

              BOUNDED BY NUCLEAR MEMBRANE               NUCLEAR MEMBRANE

               AS NUCLEAD

               4. FOR EXAMPLE-BACTERIA, MYCRO-        4. FOR EXAMPLE- PLANTS, 

                    PLASMAS                                                              ANIMALS

Q3. WHAT WOULD HAPPEN IF THE PLASMA MEMBRANE RUPTURES OR BREAKS DOWN?

ANS. IF THE PLASMS MEMBRANE RUPTUREA OR BREAKS DOWN THEN WILL BE SPILLING OF CYTOPLASM AND CELL ORGANELLES BURSTING OF LYSOSOME AND DIGESTION CELLULAR CONTENTS.

 

Q4.  WHAT WOULD HAPPEN TO THE LIFE OF A CELL IF THERE WAS NO GOLGI APPARATUS ?

ANS. IF THERE WAS NO GOLGI APPARATUS THEN THE MATERIAL SYNTHESISED IN [ER] WILL NOT BE PACKAGED, STORED AND TRANSPORTED TO VARIOUS TARGETS. 

LYSOSOME  FORMATION WILL ALSO NOT TAKE PLACE .HENCEINTRACELLULAR DIGESTIONAND CLEASING OF THE CELL CANNOT BE  BROUGHT ABOUT. THIRDLY FORMATION OF NEW PLASMA MEMBRANE WILL NOT OCCUR.

Q5. WHICH ORGANELLE IS KNOWN AS THE POWERHOUSE OF THE CELL? WHY? 

ANS. MITOCHONDRIA IS KNOWN AS THE POWERHOUSE OF THE CELL. THE ENERGY REQUIRED  FOR VARIOUS CHEMICAL ACTIVIES NEEDED FOR LIFE IS RELEASED BY MIT OCHONDRIA IN THE FORM OF ATP  MOLECULES.

Q6.WHERE DO THE LIPIDS AND POROTEINS COSTITUTING THE CELLMEMBRANE GET SYNTHESISED?

ANS. PROTEINS ARE SYNTHESISED OVER RIBOSOMES OF RER WHILE LIPIDS ARE SYNTHESIZED OVER SER.

Q7. HOW DOES AN AMOEBA OBTAIN ITS FOOD?

ANS.AMOBEA ENGULFS ITS FOOD WITH YHE HELP OF PSEDOPDODIA, WHICH ARE  PROJECTIONS OF THE CELL MEMBRANE .IT ENCIRCLES THE FOOD PARTICLE AND INGESTS IT BY THE PROCESS OF PHAGOCYTOSIS .ONCE THE FOOD BECOMES A PART OF THE CELL IT IS REFERRED AS PHAGOSOME OR FOOD VACUOLE . INTRACELLULAR DIGESTION TAKE PLACE.THE DIGESTED FOOD IS ABSORED BY THE SURROUNDING   CYTOPLASM AND THE UNDIGESTION MATTER IS THROWN OUT OF THE CELLBY THE PROCESS OF EXOCYTOSIS.

Q8.WHAT IS OSMOSIS? 

ANS. OSMOSIS IS THE PROCESS OF MOVEMENT OF WATER MOLECULES FROM A REGION OF LOW SOLUTE CONCENTRATION TI THE REGION OF HIGH SOLUTE CONCENTRATION VIA SEMIPERMEABLE MEMBRANE.