Past Questions and Answers Photosynthesis and Minerals Nutrition



1.      The mineral nutrient that is most bound to the soil is

A. phosphorus       C. iron

B. calcium             D. potassium

2.      The mineral nutrient that easily gets leached out of the soil is

A. phosphorus       C. magnesium

B. calcium             D. nitrate

3.      Most commercial fertilizers are rich in salts of

A. sodium, iron and calcium

B. nitrogen, phosphorus and potassium

C. iron, copper and nitrogen

D. calcium, sodium and phosphorus

4.      If a healthy potted plant is continuously kept in dim light

A. the rate of respiration may equal that of photosynthesis

B. more carbon dioxide and water are taken in

C. respiration may be halted

D. the volume of oxygen released increase

5.      The seedlings in rice field were found to have thin lanky growth with reddish leaves and poor root development. This is because the soil lacks

A. sulphur                  C. potassium

B. phosphorus            D. iron

6.      The first step in the process of photosynthesis is the

A. activation of the chlorophyll

B. photolysis of water

C. reduction of carbon dioxide

D. formation of sugar

7.      Etiolation is caused by the influence of

A. minerals salt        C. carbon dioxide

B. water                    D. light

8.      Free nitrogen is released to the atmosphere by

A. Nitrogen-fixing bacteria

B. nitrifying bacteria

C. denitrifying bacteria

D. saprophytic bacteria

9.      Which of the following is formed immediately after the first product of photosynthesis?

A. Lipid                  C. Oxygen

B. Starch                 D. Sugar

10.  Interveinal chlorosis is normally associated with the deficiency of

A. magnesium         C. iron

B. potassium           D. calcium

11.  2H2 → 2H2 + O2(g). The equation above represents a part of the light stage of photosynthesis. Which of the following must be presents for this reaction to occur?

A. Enzyme and light energy

B. Carbon dioxide and light energy

C. Light energy and chlorophyll

D. Chlorophyll and enzyme

12.  Trace elements are required by plants mainly for the

A. formation of pigments and enzymes

B. production of energy and hormones

C. manufactured of carbohydrates

D. manufacture of proteins

13.  In a water culture experiment, a plant showed poor growth and yellowing of the leaves. These may be due to deficiency in

A. copper             C. magnesium

B. iron                 D. calcium

14.  The dark reaction of photosynthesis involves

A. fixation of carbon (IV) oxide to give six-carbon sugar

B. fixation of carbon (IV) oxide with the help of oxygen

C. use of carbon (IV) oxide to produce glucose using ATP

D. fixation of carbon (IV) oxide on chlorophyll using hydrogen

15.  Yellowing of leaves is a symptom associated with deficiency of

A. iron, calcium and magnesium

B. nitrogen, sulphur and potassium

C. sulphur, phosphorus and iron

D. magnesium, nitrogen and iron

16.        The substance labelled I originates from

A. III only         C. I and IV

B. IV only        D. III and IV

17.        The gas occupying the space labelled I is

A. carbon (IV) oxide       C. hydrogen

B. nitrogen                       D. oxygen

18.        Which of the following statement is correct about the experiment?

A. The flask must be of the conical type

B. Caustic soda can be replaced with distilled water

C. The enclosed leaf will lose its green colour

D. The leaves outside the flask serve as control

19.        Which of the following factors will be investigated if a potted plant with variegated leaves is used in photosynthesis experiment?

A.    light                      C. chlorophyll

B.     carbon dioxide     D. water

20.        The experimental set-up can be used to demonstrate that

A. light is necessary for photosynthesis

B. oxygen is necessary for photosynthesis

C. photosynthesis occurs in the leaves of plants

D. carbon (IV) oxide is necessary for photosynthesis


1. C

6. A

11. C

16. B

2. D

7. A

12. A

17. D

3. B

8. C

13. B

18. D

4. A

9. B

14. A

19. C

5. B

10. A

15. D

20. D


1.      (SSCE 1995, Q2) (a) How does the structure of the leaf adapt it to its photosynthesis function?

(b) How will you demonstrate experimentally that chlorophyll is necessary for photosynthesis?


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2.      (SSCE 1997) Describe the light stage of photosynthesis

(i)                 State the importance of photosynthesis to life in general.


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3.      (SSCE 2002 Q2) (a) Explain briefly how temperature affect photosynthesis.

(ii) State the other factors which affect photosynthesis

(a)   Describe a test that can be used to show that photosynthesis has taken place in a leaf.


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4.      (SSCE, 2002 Q5) (c) state four natural process which replace the CO2 for photosynthesis.


ü  Burning of vegetation by natural causes

ü  Respiration by living organisms

ü  Emission from volcanoes

ü  Decay of organic matter

5.      (SSCE 2003 Q4) (b) Explain how the structure of a leaf adapts it to its function as photosynthetic organ.


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6.      (WASSCE 2006 Q1) (c) write an equation to represent the first stage of photosynthesis.


7.      (WASSCE 2009 Q2) (d) State the importance of the following mineral elements in plants;

(i) Iron      (ii) Calcium      (iii) Nitrogen

8.      (WASSCE 2009 Q6) (a) Explain how the structure of a leaf adapts it to photosynthetic function.

(b) Describe what happens in the dark stage of photosynthesis

(c) State three factors each that affects:

(i) the rate of photosynthesis 


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(b) This stage is light independent. It occurs in the stroma of the chloroplast.

Carbon dioxide converts 5-C compound into unstable 6-C compound. The resulting 6-C compound breaks down into two molecules of a 3-C compound. The 3-C sugar is used in the synthesis of simple sugar using NADPH2 and ATP produced in the light stage.

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9.      (SSCE 2011, Q2) With the aid of diagram 8-10cm long, describe how oxygen is given out as a by-product of photosynthesis.


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10.      (WASSCE 2012) 2(c) State one function of the following elements in plant nutrition

(i) magnesium          (iii) molybdenum

(ii) calcium               (iv) copper

11.       (WASSCE 2014) State three ways in which photosynthesis of is important to the environment


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