,Journey of a Water Drop
Through a Plant.
•AlJohara Tj AlThani x
8B
Basic Description
In every plant, water moves from the
ground, through the roots, up the stem,
enters the leaves, and finally exits from the
plant through the leaves.
The roots are covered in fine root hairs.
The stem contains a tube known as the xylem.
The leaves use the water to make energy.
There are openings called stomata in the leaves to allow the water to escape.
WHAT actually happens ?
Water enters the ground when it rains and moves through the Earth in
the direction of the fine root hairs. Because the hairs are so fine
they can easily absorb water through a process known as osmosis.
Osmosis describes how an area of high
concentration of water moves to an area of
low concentration.
This fact is true for all cells in animals, as well as
plants.
WHAT actually happens ?
If there is water in the ground, it will move in
the direction of the roots. Because there
are thousands of tiny root hairs they are
able to absorb the water easily and allow it
to start its journey through the plant.
From the root hairs, the water drop enters
the roots and continues to move by
cohesion.
Cohesion
Cohesion means sticking together, and water drops stick together as
they move through the plant.
The force which makes the water move is caused by
transpiration, which means that because of the
effects of heat, humidity, or strong winds, water
escapes through the stomata in the leaves.
This causes water to evaporate into the
atmosphere and to pull more water up the
stem.
Benefits of Water
Firstly, water allows a plant to take in
minerals from the soil. Plants need
minerals to help them grow.
Secondly, water gives shape and rigidity to the
leaves so that if there is not enough water for
the plant, it’s leaves begin to wilt.
Finally, water is used in the leaves to make
energy through the process of
photosynthesis.
With Water
Without Water
Photosynthesis
Plants are the only organisms which can
make their own food.
In the leaf, water combines with energy
stored from light and carbon dioxide in the
chloroplast to make glucose or starch.
This is the food for the plant.
Photosynthesis Equation
carbon dioxide + water (+
light energy) → glucose +
oxygen
=
6 CO2 + 6 H2O → C6H12O6
+ 6 O2
What Next ?
After photosynthesis takes place, the plant has
energy in the form of glucose and starch, but it
also has extra water and oxygen.
On the under side of a leaf, there are small openings called stomata.
These let water out and carbon dioxide in.
The water is moved out of the leaf, into the
atmosphere by the process of respiration.
Respiration
The respiration takes place all the time but
photosynthesis only takes place in the day.
Some of the water is kept inside the plant to
move the glucose or starch around,
through tubes called the phloem.
As water exits the leaves, new water is
drawn up the stem and into the leaves to
be used for photosynthesis again.