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BIOLOGY TOPICAL QUESTIONS AND ANSWERS-Growth and development in (a) plants (b) animals


1.         a) Name the hormone which controls moulting  in insects.                                                  

           b) State the importance of moultng in insects.                                                                      

2.         The illustration below represents an eye defect

            a) Name the eye defect .                                                                                                                     b) Name the lenses that can be used to correct the defect.  

3.         (a) State two functions of the kidney                                                                                    

            (b) Name two substances that are not found in urine of a healthy person                            

            (c) Name two diseases that affect the kidney                                                                         4.         The diagram below represents a growth pattern of arthropods.


(a) Name the type of growth pattern represented on the graph.                                            

            (b)Identify the process represented by X.                                                                             

            (c) Which hormone is responsible for process at X in 15 (b) above?                                   

5.         Distinguish between natural and acquired immunity.                                                                       
6.         The cells shown below were obtained from different parts of a young root tip:

Give the name of the zone from which each cell was obtained A, B and C                                     

7.         Differentiate between continuous and discontinuous variations                                           

8.         An experiment was set-up as shown in the diagram below:-

(a) Suggest the possible aim of this experiment                    

(b) Account for the observation at the end of the experiment                                               

9.         State the location of each of the following plant meristematic tissues:-                               

            (i) Vascular cambium                                                                                                             

            (ii) Intercalary meristem        

10.       Define the following terms:    a) Growth                                                                                           

                                                            b) Development                                                                                 

11.       State two advantages of metamorphosis in the life insects                                                   

12.       State one disadvantage of exoskeleton in insects.                                                                 

13.       Distinguish between primary growth and secondary growth in a flowering plant              

14.       What is the role of the following to a germinating seed:       (i) Oxygen                                          

                                                                                                            (ii) Cotyledons                                   

15.       Give three applications of plant growth hormones in agriculture                            

16.       State two functions of calcium in the human body                                                              

17.       State the biological importance of ecdysis in arthropods                                                      

18.       The diagram below represents a stage during the process of germination.

(a) (i) Name the type of germination illustrated in the diagram

                 (ii) Give a reason for your answer in (a) (i) above.                                                          

            (b) Give two functions of the part labelled X                                                            

19.       In an experiment young potted seedlings were placed in a dark box with unilateral light source             as shown below

            (a) What was the aim of the experiment?                                                                              

            (b) State the observations made on the seedlings after 3 days                                              

20.       The graph below represents the growth of animals in a certain phylum.

(a) Name the type of growth pattern shown on the graph.                                                    

            (b) Identify the process represents by x.                                                                                

 (c) Name the hormone responsible for the process in B above.                                           

21.       (a) State the role of the vascular cambium in plant growth and development.                     

(b) Explain why monocotyledons plants do not undergo secondary thickening.                  

22.       Explain how placenta is adapted to its functions                                                                  

23.       State the role of the following during germination:                                                                

            (a) oxygen

            (b) enzyme                                                                                                                             

24.       Name the type of responses exhibited by:-

            (a) (i) Marine crabs burrowing into the sand to avoid dilution of their body fluids             

                 (ii) Chlamy domonas plant moving towards a region of  high light intensity                  

            (b) (i)What type of neuron is drawn above?                                                                            

                 (ii) Using an arrow, show the direction of the nerve impulse                                                 

                  (iii) Name the part labelled X      

                  (iv) State the function of part labelled Y  .                                                                                   (c) Give two differences between reflex action and conditioned reflex action
25.       The experiment set – up below was designed to investigate an aspect of germination

a) Why was potassium hydroxide pellets used in this experiment?                                      

            b) What was the role of moist cotton wool in this experiment?                                            

            c) i) By means of an arrow, indicate on the diagram the direction in which red dye would move

       during the experiment.                                                                                                    

     ii) Give reason for your answer in c(i) above.                                                                  

            d) Other than the factor investigated above, state any other one factor necessary for germination


26.       The following data represents the development in dry mass of germinating seedlings within 18


Time in weeks012461013151618
Dry mass in grammes0.123.210183244454438

            (a) Using suitable scales plot a graph of dry mass against time                                                        

            (b) Write reference to the graph, explain the changes in dry mass between:-

                 (i) Week 0 to 2

                 (ii) Week 5 to 13                                                                                                                           

                 (iii) Week 16 – 18                                                                                                             

            (c) (i) What is the significance of time zero?                                                                                                

                 (ii) What difference would be expected from the above results if the experiment started with

                        the seeds? Give a reason for your answer                                                                              

            (d) (i) Describe how you carry out the experiment to obtain dry mass in the respective weeks       

                  (ii) State one advantage of using dry mass instead of fresh weight in estimating growth of an


27.       The diagram below represents a set-up that was used to investigate the effect of rotation on the

            growth of a bean radicle. The set-up allowed the seedling to rotate slowly and continuously for            seven days

(a) Name the piece of apparatus illustrated                                                                           

            (b) (i) State the observation made on the shape of the radicle after seven days                               

                 (ii) Explain the observation in (b) (i) above                                                                                 

(c) Suggest a suitable control for this experiment     

            (d) Give any four importance of tropism in plants   

28.       An experiment was carried out to determine the growth rates of variety of bamboo and a variety of maize in two adjacent plots. The average height and average dry weight of plants from the two    

            populations were determined over a period of twenty weeks. The data is as shown below:-

a) On the same axes, plot a graph to show the changes in average weight of the bamboo and maize

     plants over time                                                                                                    

(b) (i) Which of the two plants had a higher productivity by the end of the experiment?                

                 (ii) Give a reason for your answer in (b)(i) above                                                            

            (c) Explain the following:

                (i) Between weeks 14 and 18 the average height of maize plants remained constant while the

                     average dry weight increased                                                                                                   

                (ii) Dry weight was used instead of fresh weight in this experiment                                            

                (iii) Describe how the average height and average dry weight of plants were determined in

                       this experiment;

            (d) Why was it appropriate in this experiment to use both weight and height?                                

            (e) Give a reason why secondary thickening does not occur in bamboo and maize plants  

29.       (a) What is meant by the term fertilization ?                                                           

            (b) (i) Name the type of cell division that produces gametes                                                

                  (ii) Where does the type of cell division mentioned above occur in mammals?             

            (c) What happens to the wall of the uterus;

                 (i) before the release of an egg ?                                                              

                   (ii) if no fertilization occurs?                                                                              

           (b) How is the placenta adapted to its functions?                                                       

30.       The relationship between seed fresh mass in the lupin lupinus and percentage seed germination,

            percentage seedling survival  and  seedling fresh mass is  shown  in the  table;                   

Seed fresh Mass mg-1Percentage germinationPercentage  of seedlings  surviving 2 leaf stageMean seedling fresh  mass 5 weeks  after germination/mg
Below 16 17-25 26-35 36-45 Above 4541.9 90.2 95.6 97.5 100.084.6 96.8 98.8 100.0 100.024.3 44.2 60.7 86.4 106.4

            a) How was percentage germination in column two of the table calculated?                       

            b) Why was seed fresh mass preferred to seed dry mass to take measurements of the seed weight   

                 in the experiment                                                                                                              

            c) i) Explain why the  measurements  of  mean seedling  fresh  mass (5) weeks after germinated 

                   may not have  been   an accurate  measurement  of growth  that  had  occurred           

     ii) How could more meaningful and accurate measurement been obtained in c(i) above?

            d) With reference to the figures in the taste indicate the relationship between seed fresh mass 

                  and percentage seed  germination,  percentage  seedling survival and seedling fresh mass       

            e) Suggest an explanation why seedling produced from large seeds grow more rapidly than the

                  seedling produced from small seeds   


a) State the relationship between rate of reaction and enzyme concentration                       

            b) Account for the rate of reactions between; i) Q and R                                                                    

                                                                                    ii) R and S                                                                                                                              

                                                                        iii) U and V                                                                

c) Name one other factor that affects enzyme action, not illustrated above                         

32.       Carefully study the figure below and answer the questions that follow:-


The seedling with straight radicle and plumule was attached to a machine horizontally as shown

             above. The machine rotates making one revolution in 15minutes.

             (a) Draw how the seedling would look like after one week                                                 

            (b) Explain your drawing in (a) above                                                                                  

            (c) Name the machine used in the experiment above                                                            

            (d) What would happen if the seedling was put horizontally outside the machine               

            (e) Name  the stimuli investigated and type(s) of response expected in the experiment      

33.       (a) Give the form in which each of the following substances ate transport in mammalian blood:

                 (i) Carbon (IV) oxide                                                                                                        

                  (ii) Oxygen                                                                                                                       

            (b) Give two functions of pleural membrane

            (c) Explain why formation of carboxyhaemoglobin in the blood of a mammal results in death        

(d) Other than stomata, name two other gaseous exchange surfaces in plants                     

34.       In an experiment the radicle of a seedling was marked equidistant using Indian ink as shown              in the diagram below:  


(a) What was the aim of the experiment?                                                                              

            (b) On the diagram below mark on the radicle to show the appearance of the marks after 3days


(c ) State three characteristics of cells found just behind the root cap of a radicle                            (d) Give two factors inside a seed that causes seed dormancy


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