,Photosynthesis is a physio-chemical process by
which green plants use light energy {solar energy}
to synthesis organic compounds
It is the basis of all life on earth
Ultimately, all living forms depend on sunlight for
energy.
It is the primary source of all food on earth.
It releases oxygen into the atmosphere
Take a variegated leaf {or leaf partially
covered with black paper} that was exposed
to light
Test the leaves for starch
it shows that photosynthesis occurs only in
green parts of the leaves in presence of light
, A part of a leaf is enclosed in a
test tube containing KOH soaked
cotton {which absorbs CO2}
The other half of the leaf is
exposed to air
Place this setup in light for
sometime .
Test the leaf for presence of
starch
Exposed part shows positive for
starch and portion in the tube
shows negative
This proves that CO2 is required
Hugo von Mohl
for photosynthesis
Priestley performed experiments
to prove the role of air in the
growth of green plants
He discovered oxygen in 1774
He observed that a candle
burning in a closed bell jar gets
extinguished. Similarly, a mouse
is suffocated in a closed jar
He continued that a burning candle or a breathing animal
damage the air
He placed a mint plant in the bell jar
He found that the mouse stayed alive and the candle
continued to burn
He hypothesised that plants restore to the air whatever
breathing animals and burning candles remove
which green plants use light energy {solar energy}
to synthesis organic compounds
It is the basis of all life on earth
Ultimately, all living forms depend on sunlight for
energy.
It is the primary source of all food on earth.
It releases oxygen into the atmosphere
Take a variegated leaf {or leaf partially
covered with black paper} that was exposed
to light
Test the leaves for starch
it shows that photosynthesis occurs only in
green parts of the leaves in presence of light
, A part of a leaf is enclosed in a
test tube containing KOH soaked
cotton {which absorbs CO2}
The other half of the leaf is
exposed to air
Place this setup in light for
sometime .
Test the leaf for presence of
starch
Exposed part shows positive for
starch and portion in the tube
shows negative
This proves that CO2 is required
Hugo von Mohl
for photosynthesis
Priestley performed experiments
to prove the role of air in the
growth of green plants
He discovered oxygen in 1774
He observed that a candle
burning in a closed bell jar gets
extinguished. Similarly, a mouse
is suffocated in a closed jar
He continued that a burning candle or a breathing animal
damage the air
He placed a mint plant in the bell jar
He found that the mouse stayed alive and the candle
continued to burn
He hypothesised that plants restore to the air whatever
breathing animals and burning candles remove
