 To
describe how plants obtain
their nutrition
 Explain the process of
photosynthesis and the role of
stomata
 Analyse the role of green plants in
the food and energy chain
Define  Heterotrophs
 Autotrophs
Which category do plants fall under?
 Photosynthesis
 Transpiration



The roots absorb Minerals from the soil,
which contain elements which are essential
for plant growth.
These are of two types Macro nutrients – Elements required in large
quantities eg C, H, O, N,P, S,K, Ca, Mg.
–
Elements are required in very
small amounts (trace elements)
 They
include Fe, Cu, Mn, Mb
(Molybdenum), Zn and B(Boron).
Of these Fe is the most important.
 Among
these nutrients,
Carbon is absorbed from the air as
carbon dioxide
Hydrogen and oxygen are
absorbed from water and soil.


Minerals must be dissolved in water and are
absorbed by the root hairs of the plant.
Once absorbed, the mineral solution is
transported through the stems to leaves and
other parts of the plant through the vascular
bundles.


Lack of any essential nutrient causes
deficiency diseases in plants.
Please study table on pg 51


Leaves are the main organs of photosynthesis
because their flat shape is ideal for trapping
sunlight.
They are arranged in a leaf mosaic to expose
them equally to the sun. Their cells have
chloroplasts to trap the energy from the sun.
The network of veins bring in water.

Guard cells are two bean shaped structures
which control the openings called stomata.
These stomata are responsible for the
exchange of gases and transpiration





Photosynthesis requires sunlight, water,
carbon dioxide and chlorophyll.
Chlorophyll captures energy from sunlight
and uses it to combine CO2 with H2o to form
glucose, a carbohydrate. These carbohydrate
molecules join to form starch, proteins and
fats.
IMPORTANCE: This is the only process which
gives:
Renewable source of food
restores oxygen to the atmosphere