Transcript Plants and water 2 - Miss Jan`s Science Wikispace

Do Now - Who am I? (part 2)
1.
2.
3.
“I am a sub-member of a particular group of
plants. The veins in my leaves are branched.
I have two food storage areas in my seed. My
flowers tend to be bright and colourful. I
usually use insects or birds for pollination.”
“I am a very simple group of plants. I live in
the water. I form stringy slime.”
“I am a cross between an algae and a moss. I
tend to live on tree trunks and stones. I need
water to reproduce but can survive okay
without it.”
Plants and water 2
Ms Jan
Osmosis
powers the
movement of
water in plants
– as water
escapes the
leaves it is
replaced by
water moving
up the stem
from the roots
Osmosis causes transpiration
Water escapes
the leaves by
evaporation
Water moves up
the stem to
replace the water
lost in the leaves
it is drawn up by
the transpiration
stream
Water moves
into the root
cells by osmosis
because there is
more water in
the soil than in
the root cells
Finding the stomata

Using this picture, draw a
diagram of the stomata in
your book (title: The
Stomata)
Stoma
(stomata = plural)
Review of global warming
Review of global warming

Draw a flow diagram of the process of global
warming. E.g.
CO2 emission via
deforestation, burning
fossil fuels, etc.
Temperature increases on
Earth – leading to melting
polar ice caps and rising
sea level.
CO2 contributes to
greenhouse gases in the
earth’s atmosphere
Greenhouse gases traps
heat (UV radiation)
inside Earth’s
atmosphere.
NOT the same as the ozone layer!!
Plant Leaves
Ms Jan
Plant leaves SLOs
 Label
a cross section diagram of a leaf
 Explain the role of the stoma in the leaf
 Explain why leaves tend to be very flat
and broad
page 82 in NMS 1
Leaves are designed to:
 Catch
as much sunlight as possible
– wide and flat
 Use as much sunlight as possible –
thin with lots of chlorophyll
 Allow CO2 in and O2 out –
stomata and air spaces
Gas exchange
Guard cells
Guard cells (guards the stomata)
control how much air and water
enter and leave the leaves. If a
plant loses too much water it wilts.
The cuticle (waxy layer on the top)
also stops water loss.
Plant structure
Plants are designed to spread out
their leaves to get as much
sunlight as possible without
blocking other leaves – usually a
pyramid shape.
Plant adaptations
a)
b)
c)
Leaves are generally wide, thin and flat.
bigger surface area to catch more of the
sunlight needed for photosynthesis.
Most leaves are at the end of branches.
less sheltered from the sun, so can capture
more of the sunlight.
Leaves are flexible but tough.
Leaves get blown around in the wind and
weather so needs to be able to move.
d)
e)
f)
Many leaves are darker green on top.
More chloroplasts are present in the top of the leaf
to capture more sunlight.
Most stomata are on the underside of leaves.
This allows gas exchange (carbon dioxide and
oxygen) to occur without taking space up on the top
of the leaf where photosynthesis has to occur.
Many plants lose their leaves in winter.
A lot of plants make enough food to tide them over
the winter. It is more energy efficient for them to
remain dormant over the winter.