chapter 2

ANSWER  KEY 

ACTIVITY  1

A – Nucleus                                E – Ribosomes

B – Mitochondrion                       F – Endoplasmic reticulum

C – Centrioles                             G – Cytoplasm

D – Plasma membrane               H – Golgi apparatus

ACTIVITY  2

A – Golgi apparatus              E – Mitochondrion

B – Chloroplast                     F – Tonoplast

C – Vacuole                          G – Nucleus

D – Cell wall                          H – Plasma membrane

ACTIVITY  3

1.   Cells                                  9.   Ribosomes

2.   Organelles                        10.  Rough endoplasmic reticulum

3.   Plasma membrane           11.  Smooth endoplasmic reticulum 

4.   Cell wall                            12.  Golgi apparatus

5.   Cytoplasm                         13.  Lysosomes

6.   Nucleus                             14.  Centrioles

7.   Vacuole , cell sap              15.  Chloroplast

8.   Mitochondrion

OBJECTIVE  QUESTIONS

1.   A                        6.    C

2.   B                        7.    D

3.   A                        8.    B

4.   D                        9.    C

5.   B                       10.   D

STRUCTURED  QUESTIONS

1 (a)   X – Animal cell                 Y – Plant cell

   (b) (i)   A plant cell has cell wall

        (ii)   A plant cell has large vacuole

        (iii)  A plant cell has chloroplast

   (c) (i)   P – Mitochondrion      (ii)   R – Nucleus      (iii)   S – Chloroplast

   (d)   Q  is a vacuole. It controls the osmotic balance and the turgor pressure in

           a cell. This is important especially to the herbaceous plants, which depend

           on turgidity for support.

   (e)  Organelle  P  is a mitochondrion, which is a site for generating energy.

          Energy is required for cell activities such as cell division, excretion and

          respiration. If there is no organelle  P , cell activities will stop.

 ESSAY QUESTION.

1 (a)  Functional diagram : Cell wall , vacuole , chloroplasts

                                           and mitochondrion                             2 marks

                                                                                                  

          Label : Cell wall, vacuole, chloroplasts,

                     nucleus and mitochondrion.         4 – 5 correct  =    3 marks

                                                                          2 – 3 correct  =    2 marks

                                                                            <  3 correct  =    1 mark

                                                                                                   ( 5 marks )

                     

                                         

(b)  Differences between animal cells and plant cells.

Animal cells	Plant cells
1)  Usually smaller in size	Usually bigger in size
2) Do not have a fixed  shape	Have a fixed shape
3) Do not have cell walls	Have cell walls
4) Do not have chloroplasts	All green plants have chloroplasts which contain chlorophyll
5)  Do not have vacuoles. If present,      vacuoles are usually small and      numerous	Have a large central vacuole
6) Carbohydrate is stored in the form of     glycogen	Carbohydrate is stored in the form of  starch
7) Have centrioles	Do not have centrioles

                                                                                                  Maximum : 5 marks