Page 1 - 21. GLM OL Bio answer key 2023 (AK018)
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Unit 1: Cell structure and organisation                                                                                   2.   Across:
                                                                   1.   Chlorophyll   2.   Nucleus
                 Revision                                          5.   Differentiate   7.   Ribosomes
                 1.   (a)  It is a unit of life.                   9.   Protoplasm   13.  DNA
                    (b)  Cell membrane, cytoplasm, nucleus         14.  Biconcave    15.  Mitochondria
                 2.   (a)  Chlorophyll                             1.   Chloroplast   3.   Cytoplasm
                    (b)  It  has  a  large,  central  vacuole.  /  It  has  a  cell      4.   Cellulose   8.   Photosynthesis

                 3.  (a)  3              (b)  5                3.  (a)  Structure  Cell X  Plant cell Animal cell
                    (c)  1               (d)  2                        Cell wall  Present  Present  Absent
                    (e)  4                                             Flagellum  Present  Absent  Absent
                 4.   (a)  It is a process where cells change in shape and   capsule  Present  Absent  Absent
                        form  so  that  they  acquire  special  features  to
                        perform specific function.                     Nucleus  Absent  Present  Present
                    (b)  (i)   Long  and  narrow  structure  increases  the   Cytoplasm  Present  Present  Present
                            surface  area-to-volume  ratio  for  efficient
                            absorption of water and mineral salts     (b)  As  cell  X  is  able  to  move,  it  needs  more
                        (ii)  Contains haemoglobin to transport oxygen/  mitochondria  to  break  down  food  to  release
                                                                      energy for this movement.
                            Biconcave shape increases the surface area      (c)   All of the cells contain cytoplasm.
                            so that the rate of diffusion of oxygen in and      All of the cells have a cell membrane.
                            out the cells is faster/
                            No  nucleus  so  that  it  can  contain  more   Section C: Free response questions
                                                               1.   Proteins  made  by  the  ribosomes  in  the  rough
                 5.   (a)  An organelle is a cellular structure that performs   endoplasmic  reticulum  (RER)  are  packaged  into
                        specific functions within the cell.        vesicles. The vesicles pinch off from the RER and move
                    (b)  1:   Smooth endoplasmic reticulum (SER);   to the Golgi body. They then fuse with the membrane
                        2:   Ribosomes   3:   Golgi body           of the Golgi body to release the proteins inside it. After
                        4:   Nucleus   5:   Mitochondrion          the Golgi body modifies the proteins, they are again
                        6:   Vacuole   7:   Cell membrane          packaged into new vesicles. After the vesicles pinch
                        8:   Rough endoplasmic reticulum (RER)     off from the Golgi body, they fuse with cell membrane
                    (c)  (i)  2          (ii)  6                   to release their contents out of the cell.
                        (iii) 1          (iv) 8
                        (v)  4           (vi) 5                Unit 2: Movement of substances
                        (vii) 3          (viii) 7
                                                               Revision 1
                                                               1.   (a)  Diffusion  is  the  net  movement  of  a  substance
                 Section A: Multiple-Choice Questions                 from  a  region  of  its  higher  concentration  to  a
                                                                      region of its lower concentration.
                 1.   C    Animal  cells  do  not  have  cell  wall  and      (b)  It is the difference in concentration of a substance
                        chloroplasts.                                 between two regions.
                 2.   A    Chloroplast is another organelle that is found in      (c)  Concentration  gradient,  diffusion  distance  and
                        plant cells.                                  surface area-to-volume ratio
                 3.   A   Cell  wall  does  not  restrict  the  movement  of
                 4.   A   X is nucleus and Y is chloroplasts.  2.   (a)   False [Each substance diffuses according to its
                                                                      own concentration gradient]
                 5.   D   These are typical arrangement for plant cells.     (b)   False  [The  particles  of  a  substance  still  move
                 6.   B   Plants are living organisms that can make their   back and forth as they have kinetic energy, but
                        own food. Plant cells have cell wall.         there will be no net movement on either side of
                                                                      the regions.]
                 Section B: Short answer questions                 (c)   True
                 1.   (a)   Plant cells: Q, S                      (d)   False  [A  permeable  membrane  allows  any
                        Animal cells: P, R                            substance to pass through it.]
                    (b)   It lacks of nucleus, biconcave shape; Transports      (e)   True                    Answer Key
                        oxygen; Allows it to change shape and increase
                        its surface area as it travels through capillaries

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