| National
Curriculum Links |
Sc2 3a - that plants need .................................. light
for photosynthesis
|
| QCA
Links |
3b Helping plants grow well
In addition can be used in following QCA schemes of work
1b
Growing plants
2b Plants and animals in the local environment
5/6H Enquiry in environmental and technological contexts
|
| Learning
Objectives |
- Students recognise the effects of depriving plants of light.
- Students further develop their understanding of photosynthesis.
- Students to recognise that plants need light energy and chlorophyll
to carry out photosynthesis.
|
| Background
Organic Information |
Persistent
weeds can be a problem for many gardeners. Organic gardeners do not use
artificial chemicals to kill weeds, so they need to use other methods
to get rid of unwanted plants. One of these methods is to deprive the
plants of the light that they need in order to photosynthesise.
|
| Resources |
Light
excluding materials such as cardboard, black plastic, old carpet or weed
control membranes.
An area of weedy ground that can be covered.
|
| Time
Required |
Set-up
time: 1 hour
Investigation time: 6 months
Follow up time: 1 hour
|
| Structuring
the lesson |
|
Introduction
-
Revise with students what plants need in order to survive.
-
Discuss how an area of weeds could be cleared using this knowledge.
Activity
- Students
to cover the weedy area so that all light is excluded.
- If
you have enough ground, different areas can be covered using different
light excluding mulches. This can be used to investigate the efficiency/durability
of different materials.
- Monitor
and record what happens to the plant growth. Remember to cover the
area quickly after you have examined the plants.
- Once
the plants start to become yellow, uncover them and see how long it
takes them to become green again -if they do. Once this has occurred
cover them again.
- When
the plants are totally yellow (almost white) uncover them again and
see if they will become green.
Summary
Discuss:
- what
effect did covering the plants have?
- how
long was it before the plants started to become yellow?
- how
long did it take the plants to become green again after being uncovered?
- did
all the plants become green again? If not, which ones did and why?
*
- did
any of the plants become green again after they were uncovered for
the second time? If so which ones and why?
- Which
plants took the longest to die? Why do you think that was?
| *Roots
store food and water. The larger the root and number of roots a
plant has, the longer a plant will be able to be covered and still
be able to recover. |
|
| Skills |
| Sc1
1a - |
that
science is about thinking creatively to try and explain how living and
non- living things work, and to establish links between causes and effects.
|
| Sc1
1b- |
that
it is important to test ideas using evidence from observation and measurement.
|
| Sc1
2d - |
make
a fair test or comparison by changing one factor and observing or measuring
the effect whilst keeping other factors the same. |
| Sc1
2f - |
make
systematic observations and measurements. |
| Sc1
2i - |
make
comparisons and identify simple patterns or associations in their observations
and measurements or other data. |
| Sc1
2j - |
use
observations, measurements or other data to draw conclusions. |
| Vocabulary |
Photosynthesis
Chlorophyll
Glucose
Starch
|
| Differentiation |
All
students will provide simple explanations for changes in living things.
(Level 3)
All students demonstrate knowledge and understanding of life processes
and living things. (Level 4)
Some students will describe how plant organ functions are essential to
the plant. (Level 5)
Some students use appropriate scientific terminology when they describe
life processes in plants. (Level 6)
|
| Extension/future
learning |
Students
complete extension tasks to explain photosynthesis in terms of the underlying
chemical change.
|
| Cross
Curricular Links |
| English:
|
Writing
descriptions from observations
Collating and presenting information
|
| Mathematics:
|
Handling
data |
| Key
Skills: |
Communication
Application of number
Working with others
Problem solving |
Investigation Two