Transcript How do plants meet their needs?

Plants
• Plants supply oxygen that most organisms
need to stay alive
• They also supply food for many organisms
How do plants survive harsh weather
conditions?
• Plants adapt to get what they need from their
surroundings. They have changed over time to
be suited to get its needs met where it lives.
Germination
• Seeds need water and air to germinate.
•
Germinating means that a seed absorbs water
and swells and splits open. A tiny root begins to grow
downward and a shoot begins to grow upward.
A new plant needs 5 things to stay
healthy
1.
2.
3.
4.
5.
•
Water
Light
Carbon dioxide
Oxygen
Nutrients
These things help carry out all life processes
that take place in the plant’s cells
Photosynthesis
• Plants make their
own food by the
process of
photosynthesis.
This process
requires water,
carbon dioxide,
and sunlight.
The steps of photosynthesis
(Do Not Copy in Notes)
– Water is absorbed from the soil by the roots.
– Carbon dioxide enters the plants through stomata,
tiny openings in the leaves.
– Sunlight is also taken in by the leaves
– Chlorophyll (the green color in the leaves) takes in
the sunlight
– The energy is used to changes carbon dioxide and
water to sugar and oxygen
– The sugar (glucose) is stored in the plant, and
oxygen is released into the air.
Respiration
• Once the sugar is made, plants can use some
of the oxygen to release the chemical energy
that is stored in the sugar. This is called
respiration, when oxygen combines with
sugar to produce energy, carbon dioxide, and
water.
Vascular Plants
Xylem and Phloem
• These tubes are made
up of two kinds of
tissues – xylem and
phloem.
• Xylem tissue carries
water and nutrients
from the roots to the
leaves.
• Phloem tissue carries
sugar from the leaves
to other cells in the
plant.
Transpiration is the
loss of water from
a plant through the
stomata.
– Transpiration pulls water and minerals upward
through the plant. This is called negative pressure
or suction.
– Sugar is moved by positive pressure. It is
concentrated and moves to where it is needed
and diluted by the water.
Nonvascular plants
• Nonvascular plants are plants that lack
tissues that transport water, nutrients, and
sugar. (They don’t have xylem or phloem)
– Because they don’t have these tissues, they don’t
grow very large
• Nonvascular plants are anchored in the
soil by long cells that look like roots.
These structures are called rhizoids.
– Nonvascular plants don’t have true roots to
absorb water
• Instead they have cells that absorbs the water and
nutrients it needs directly from the soil or air
*Images provided by Google and AltaVista
– They thrive in moist, shady places such as forests