Transcript Plant Notes

Plant Unit
Autotrophs-
Make their own food (plants,
algae, monerans)
Heterotrophs- Can not make their own
food (animals,
mushrooms, bacteria)
There are two (2) types of autotrophs, those
that use, chemicals
and those that use light
Chemosynthesis turns carbon dioxide and
inorganic substances like
nitrogen and sulfur into the
food they need.
Photosynthesis turns light, carbon dioxide and
water (ingredients/raw materials)
into glucose (food), oxygen and
water (products).
What is photosynthesis? The process of converting light energy into food.
Word Equation:
Carbon Dioxide + Water Glucose + Water + Oxygen
Chemical Formula:
6CO2 + 12H2O

C6H12O6 + 6H2O + 6O2
• Chloroplasts in plant cells
Chloroplast
Three (3) major factors, which
affect the rate of photosynthesis:
1. Temperature- after a certain point the
enzymes no longer can function
(denature-change shape)
2. Light intensity- below a certain
amount of light-not enough energy
3. Concentration of CO2 and H2O- rate
of reaction increases until all
substrate and/or enzyme is being
used (saturation)
Stop and Jot!
What do you remember about
photosynthesis?
Leaves
• Photosynthesis occurs mostly in the
leaves of the plant. The leaves provide a
large surface area
for the absorption of sunlight
• Leaf Structure (Cross Section)
• Epidermis - Outer layer of the
leaf which has a waxy covering
called a cuticle. Main functions of
the outer layer is:
a). Protection of the internal tissue
of the leaf from excessive water
loss
b). Resistance to invasion by fungi
c). Protection from physical and
mechanical injury
• Stomates - Openings in the cuticle and
epidermis.
• The size of the opening is regulated by
guard cells .
• Stomates allow the exchange of oxygen ,
Carbon dioxideand water between the
external environment and internal air
spaces.
• Lenticils are tiny openings in the stem
that also allow gas exchange.
Most photosynthesis occurring in
the leaves takes place in the
palisade layer.
 Spongy
layer contains Air spaces
which are surrounded by moist
surfaces for the exchange of
gases (CO2 in and O2 out).
Some photosynthesis takes
place here as well. Do you see
the chloroplasts in the spongy
cells?
•Conducting tissues are located in the
veins of the leaves.
•The xylem carries water and minerals (up)
and phloem carries food throughout (down
and up). The vascular tissue begins in the
roots and continues through the stem to
the leaves.
Stop and Jot!
Which part of the leaf is the most
important for photosynthesis and
WHY??
ROOTS
The roots have three
(3) main jobs:
A). Anchor- plant stays put
B). Food storage- when leaves are
not there to make food
C). Absorption- water for
photosynthesis- the more surface
area (root hairs) the better
Coming off the roots are tiny
hairs called root hairs.
They increase surface area so
that more water and minerals can
be absorbed by diffusion
(osmosis) and capillary action
and transpirational pull.
How is water transported once it is
inside the roots?
Transpiration is the evaporation of
water vapor through the stomates.
There is a pulling force on the column
of water in the xylem.
It’s called transpirational pull.
Stop and Jot!
What do you remember about roots?
Flowering Plants
Reproduction in flowering plants
1. The flower is a structure specialized
for sexual reproduction.
Flowers which have both male and
female parts on the same flower are
called perfect or complete.
Use the textbook
page
612 to label the flower
2. Those that only one part, i.e. only “male” or
“female” parts are called imperfect or
incomplete.
MALE Reproductive organs: stamen which is
composed of the anther and filament. The
anther makes pollen (male gamete by meiosis).
FEMALE Reproductive organs: pistil which
is composed of the stigma, style and ovary.
The ovary makes ovules (eggs) (female
gamete by meiosis).
Pollination is the process of pollen
(sperm) going from the anther to the
stigma.
1. Self- pollination is the transfer of pollen
from the anther to the stigma of the SAME
flower or plant.
2. Cross - pollination is the transfer of pollen
from the anther on one flower to the stigma
of a DIFFERENT plant.
Cross-pollination is an adaptation which
increases variety.
•Cross-pollination
is accomplished by:
1. bees
2. wind
3. animals
Name three (3) traits
(characteristics) about the flower
that helps cross-pollination:
1. scent
2. color
3. shape
What happens after the pollen (sperm)
lands on the stigma?
1. The pollen grain germinates (is activated)
and forms a pollen tube which extends into
the ovule.
2. Sperm nuclei are formed and fertilize
(fuse with) the ovules.
3. The union of the sperm and ovule results
in a zygote.
4. The zygote develops into an embryo which
develops into a seed.
5. The ovary becomes the fruit.
6. The plant embryo consists of three (3)
parts:
epicotyl
hypocotyl
Hypocotyl - develops into the root
Epicotyl - develops into the leaves
Cotyledons - contains stored food
(nutrients) for the germinating plant
Check here to make sure you labeled the
flower correctly.
In flowering plants, seeds develop inside a
fruit. This is a special adaptation that
helps in seed dispersal.
There three (3) conditions needed for the
seed to grow:
1. Heat
2. Moisture
3. Oxygen (to perform cellular respiration)
Development of a seed into a mature plant
requires:
1. cell division (mitosis)
2. Differentiation (cells become specialized)
3. Growth
• The plants grow in the tips of the roots
and stems.
• The special tissue found in these regions
are called apical meristems.
Plant Regulation
Plants have hormones just like you do.
Hormones effect the plant’s growth and
development just like your hormones.
Auxins are plant hormones that influence
division, elongation and differentiation of
plant cells. Unequal distribution of auxins
cause unequal growth called tropisms, which
generally enhances plant survival.
Unequal distribution of auxin can be caused
by light, gravity or water.
Tropisms
Phototropism – is the response to Side A
light. Plant grows toward the light
as a result of unequal distribution of
auxins increases growth on side A
and less auxin on side B causing the
plant to bend toward the light.
Geotropism – is the response to
gravity (roots grow toward or into
the earth).
Hydrotropism – is the response to
water (roots grow toward a source
of water).
Side B