Biology Class VIII
Plant Nutrition Worksheet-Paper 2
Name:
Section:
Date:
Q1. A student investigated the effect of different wavelengths of light on the rate of
photosynthesis of the water plant, Cabomba.
The student used the apparatus shown in Fig. 1.1.
State why the student:
(i) kept the lamp at the same distance during the investigation,
______________________________________________________________________________
______________________________________________________________________________
(ii) used sodium hydrogencarbonate solution.
______________________________________________________________________________
______________________________________________________________________________
1
(iii) State three uses in a plant of the carbohydrate produced in photosynthesis.
1.........................................................................................................................................
2.........................................................................................................................................
3........................................................................................................................................
Q2. (i) Explain which chemical component of the fertilizer solution is the most important to
plants for:
making the leaves of the plants green in colour
...........................................................................................................................................
...........................................................................................................................................
the production of enzymes by cells in the leaves of the plants.
...........................................................................................................................................
...........................................................................................................................................
Q3. Researchers in Michigan investigated the rate of photosynthesis in leaves of big-tooth aspen
trees, Populus grandidentata, by placing some of the growing leaves inside transparent boxes.
The researchers measured the uptake of carbon dioxide by the leaves over a range of temperatures
from 10–40 °C. They carried out their measurements at two different concentrations of carbon
dioxide:
H – 325 ppm carbon dioxide which is close to the concentration in the atmosphere;
J-1935 ppm carbon dioxide which is a very high concentration.
The results are shown in Fig. 3.1.
2
a) Describe how the results for the aspen leaves in batch J differ from the results for the aspen
leaves in batch H. Use data from Fig. 3.1 in your answer.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
___________________________________________________________________________
(b) Explain why the rate of photosynthesis in the leaves in batch J:
(i) increases with an increase in temperature from 15 °C to 35 °C
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
__________________________________________________________________________
3
(ii) decreases at temperatures above 35 °C.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
__________________________________________________________________________
4) (a) Explain why nitrate ions and magnesium ions are important for plants.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
__________________________________________________________________________
(b) Define the term limiting factor.
______________________________________________________________________________
______________________________________________________________________________
__________________________________________________________________________
4
Q5) The diagram shows a magnified transverse section through a leaf. Name each of J, K, L and
M. beside the diagram.
(e) Write down the function of J, K, L & M
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
____________________________________________________________________________
5