Q-1 A student carried out an investigation into the effect of soil potassium on plant
growth. In this investigation, the student set up two different environments as
follows: (5 marks)
1. One plant was grown in sterile soil, provided with distilled water and placed in
bright light.
2. One plant was grown in sterile soil, provided with potassium dissolved in
distilled water and placed in bright light.
Predict what the student will have observed after two weeks of growing in these
conditions.
B Complete the table
Sr. Name of Mineral Importance of Mineral Deficiency symptoms
No.
Q-2 Fig. 1 is a diagram of a variegated leaf from a plant. The plant was exposed to
sunlight so that it could photosynthesise. (7 marks)
Fig. 1
A student tested the leaf for starch and found that:
Starch was present in the green part of the leaf
There was no starch in the white part of the leaf.
a) Explain the results of this test.
b)
1) Which plant leaf will turn blue-black after Iodine test? Why?
(Note : potassium hydroxide is CO2 absorbent)
2) By this experiment what we can conclude ?
c) Testing a leaf for the presence of starch involves several steps. Explain the
following:
(i) Boiling the leaf at the start of the procedure.
(ii) Heating ethanol in a water bath.
d) Energy is converted from one form to another during the process of
photosynthesis. Describe this energy conversion.
e) Describe at least 2 other functions of water in a plant other than for
photosynthesis.
f) State the name of the part of a leaf through which most water vapour is lost
from the plant
Q-3 Fig. 2 shows the cross section of a leaf. (6 marks)
Fig. 2
a) A plant leaf contains various structures that makes it adapted for the process of
photosynthesis. Complete the following by drawing lines to connect each listed
structure with the correct adaptation.
Structure Adaptation
Waxy cuticle Allows gas exchange to occur
Stomata Tightly packed with
chloroplasts for maximum
absorption of light
Palisade mesophyll Protect the leaf from water
loss
Spongy mesophyll Increases the surface area to
volume ratio for the diffusion
of gases
b) Structure C represents a vascular bundle. Identify two types of tissue found in
structure C.
c) Describe the function of each type of tissue identified at part (a).
d) The following could be used to write a balanced symbol equation for
photosynthesis.
. 6CO2 + 6H2O
. CO2 + 6H2O
. Light and chlorophyll
. C6H12O6 + 6O2
. 6C6H12O6 + 6O2
Which of the following show the correct balanced chemical equation for
photosynthesis?
1. 2 → 5 in the presence of 3
2. 2 → 4 in the presence of 3
3. 1 → 5 in the presence of 3
4. 1 → 4 in the presence of 3
e) In which part of the leaf would the concentration of carbon dioxide be lowest on a
warm, sunny day?
f) Which row of the table below shows the correct effects of deficiencies of essential
minerals for plant growth?
effect of magnesium ion effect of nitrate ion
deficiency deficiency
A yellow leaves stunted growth
B stunted growth long roots
C small leaves yellow leaves
D stunted growth yellow leaves
Q-4 An experiment is set up with four test tubes as shown in the diagram below.
All four test tubes are left in sunlight for 6 hours. (9 marks)
a) Which test tube would contain the least amount of dissolved carbon dioxide after 6
hours?
b) represents the carbon cycle.
Fig. 3
Use Fig. 3 to answer the following questions.
(i) Name the process labelled U.
(ii) Name a group of organisms that are responsible for the process labelled W.
(iii) List two letters that identify respiration.
(iv) State which letter identifies photosynthesis.
(v) State the word equation for aerobic respiration.
(vi) Suggest reasons why the mean percentage of carbon dioxide in the atmosphere
has increased during the last 100 years.
(vii) State two adverse effects of the increase in carbon dioxide concentration in the
atmosphere.
(viii) Carbon dioxide is a greenhouse gas. State the name of one other greenhouse
gas.
Q-5 Fig. 4 shows part of the carbon cycle. (3 marks)
Fig. 4
a) Identify the processes shown by arrows A, B and C on Fig. 5
Choose words from the list.
combustion decomposition excretion feeding fossilisation
b) On Fig 5 draw one arrow to represent photosynthesis.
Label this arrow with a letter D.
c) On Fig. 5 draw one arrow to represent respiration.
Label this arrow with a letter E
