The Photosynthesis Story
| National Curriculum links
(Key Stage 3) |
Sc1
1a |
... the interplay between
empirical questions, evidence and scientific explanations using
historical examples |
Sc1
1c |
... the ways in which …[scientists]
worked in the past, including the roles of experimentation, evidence
and creative thought in the development of scientific ideas |
Sc2
3a |
... that plants need carbon
dioxide, water and light for photosynthesis and produce biomass
and oxygen |
Resources
The Photosynthesis
Story is in the form of a brief timeline showing the development
of scientific ideas about photosynthesis, giving students the opportunity
to see where some of our knowledge about photosynthesis has come from.
Students may find it quite surprising to realise that for centuries
people actually didn't know that plants needed light, water and carbon
dioxide to make food, or that chlorophyll existed!
Charles Bonnet
- a brief summary of the work of a deaf (and eventually blind) scientist
who was one of the earliest true biologists. He is credited with being
the first person to carry out the well-known experiment in which a plant
submerged in water is illuminated by bright light, causing bubbles of
gas to form on the leaves.
Joseph Priestley's
experiments showed that plants absorb carbon dioxide and give off oxygen,
although he didn't describe it in exactly this way - these gases were
not properly named or understood at the time that Priestley was working.
He also linked the production of oxygen by plants to the respiratory
needs of animals.
Melvin Calvin
worked out the detailed biochemistry of photosynthesis using carbon-14
tracers, the first scientist to use radioactive substances in this way.
Although subsequent work on photosynthesis has provided further detail
abobut its exact mechanisms, it is to Calvin we owe our present understanding
of the chemistry that plants use to harness the energy in sunlight.
Activities
| Activity
1 |
|
- Questions based on the timeline encourage students to look
at the importance of different ideas and the role of experimentation
in developing understanding of photosynthesis.
|
| Activity
2 |
|
- Students select one of the scientists mentioned in the timeline
and find out more about them, producing a brief biography in
a format similar to those found here.
|
| Activity
3 |
|
- Students analyse the information about the development of
our ideas on photosynthesis. They are given a number of facts
about photosynthesis and asked to make a table linking current
knowledge with the scientist who was concerned with discovering
and develping the idea.
|
|
