We will learn
• The factors
that affect
the rate of
plant
growth.
• The idea of
limiting
factors.
Light
intensity
(Lux)
0
5
10
15
20
25
30
35
40
45
50
Number of
bubbles per
minute
0
17
27
36
43
46
48
52
60
60
60
Describe the
pattern that the
graph shows.
Explain why the
number of
bubbles rises at
first.
Explain why the
number of
bubbles then
stays the same.
How could you
get the plant to
make more than
60 bubbles per
minute?
We will learn
• The factors
that affect
the rate of
plant
growth.
• The idea of
limiting
factors.
We will learn
• The factors
that affect
the rate of
plant
growth.
• The idea of
limiting
factors.
We will learn
Carbon dioxide
• The factors
that affect
the rate of
plant
growth.
Water
• The idea of
limiting
factors.
Temperature
Light
Colour of light
Chlorophyll can
only absorb some
types of light
It speeds up or
slows down
chemical
reactions
It is needed for
photosynthesis
and it helps the
plant support its
leaves
It is a raw material
for photosynthesis
It provides energy
for the chemical
reaction
A – To find out if temperature affects photosynthesis.
Temperature (oC)
15
30
45
60
Number of bubbles in 1 minute
5
17
38
0
B – To find out if the colour of light makes a difference to photosynthesis.
Colour of light
blue
green
yellow
red
Number of bubbles in 1 minute
27
4
16
24

Cut out and stick in each results table and draw a bar chart to display
each set of results.

Write a conclusion for each investigation.
What will the gas at X be?
Why did this covered leaf only have starch in its
middle?
What would you see if this leaf was tested for
starch?
Which leaf will have starch in it?
The graph shows how chlorophyll absorbs different
wavelengths of light.
Why are trees green?
The indicator is red. It turns yellow when carbon
dioxide is added or purple when carbon dioxide is
taken from it.
What colour will each experiment go?
Say why you think that each step is needed when
you tested the leaf for starch.
I boiled the leaf in water first so that…
What do the results show about the leaf?