Transcript Chapter 11/12 PLANT REPRODUCTION

Chapter 10/11
P. 272
PLANT
REPRODUCTION
Growing Seasons:
1) annual
- lives one growing
season.
ex. petunia
ex. marigold
2) Biennials - lives two growing
seasons.
Ex. Carrot
(it reproduces in the
second year)
- most herbaceous
stem plants are
annuals or
biennials.
3) Perennials - live year after year.
Ex. Maple tree,
grass.
- usually woody
stem plants.
- each year the stem
grows wider and
forms the annual
growth ring.
- created by the
cambium.
ANGIOSPERM REPRODUCTION
Flower Anatomy
(p. 285)
1. Stamen
- the male part
of the flower.
Anther - contains
pollen grains.
Filament - threadlike structure that
holds up the anther.
STAMEN
- can you identify
which is the
anther and the
filament?
2) Pistil - the female part of the
flower.
Stigma - covered with a
sticky substance to
capture pollen.
Style - the thin ‘neck’ to
support the stigma.
Ovary - holds the
ovules which turn into
seeds after
fertilization.
Which is the
pistil?
Which is the
stamen?
Sepals
- leaves which protect
the developing
petals.
Petals
- protect the stamen
and pistil.
- often colorful and
have an odor to
attract insects for
pollination.
Perfect Flowers
- have both male
and female parts.
Imperfect Flowers
- has a pistil or a
stamen - not both.
- needs another
plant for
pollination.
Ex. cottonwood tree
ASSIGNMENT:
Worksheet
“Seed Reproduction”
Pollination
- the transfer of
pollen from an
anther to a stigma.
Cross-pollination
- pollen from a
anther to a different
plant’s stigma
- by wind, insects.
Self-pollination
- when the stigma
receives pollen
from the anther of
the same flower.
- must be a perfect
flower
More Pollinators
Fertilization
- occurs after
pollination.
- a pollen tube grows
thru the style.
- The pollen (a male
sperm cell) then
fertilizes the ovule
which turns into a
seed.
Pollen tube example: Corn “silk”
Fertilization
After pollination, the petals will fall
off. Why?
Pollination has been completed. The petals are
no longer needed.
After fertilization, the
ovary develops into
a fruit.
- it holds and
protects the seeds.
Types of Fruit
1) Fleshy
Ex. orange, tomato,
cherry.
2) Dry
Ex. Beans, corn,
peas, walnuts.
Seed Anatomy
Embryo
Seed Coat
Cotyledon
ASSIGNMENT:
WORKSHEET
“FLOWER ANATOMY”
Seed Dissemination
- how seeds can be
spread. (p. 289)
1) Carried by wind
- “winged” fruit
Ex. dandelions,
cottonwood
2) Carried by animals
Ex. Cockle burrs
caught in fur.
3) Eaten by animals
- excreted with the
waste.
PLANT PROCESSES
GAS EXCHANGE
- occurs in the leaf’s
stomates.
- CO2 enters thru
the stomate.
- O2 exits thru the
stomate.
- necessary for
photosynthesis.
Water vapor also escapes through
the stomates.
- called
transpiration.
More transpiration….
PHOTOSYNTHESIS
- the process of
turning light
energy into food.
- the needed
chemical is
chlorophyll.
- it traps
sunlight.
- it also needs
CO2 and H2O
to make
food and
oxygen.
6CO2 + 6H2O + light
C6H12O6 + 6O2
chlorophyll
6 molecules of
carbon dioxide
and 6 molecules
of water.
One molecule of
glucose and 6
molecules of oxygen.
C6H12O6 = glucose - a sugar which is used
as energy or stored in roots and stems.
6CO2 + 6H2O + light
C6H12O6 + 6O2
chlorophyll
The oxygen is mostly released as a waste.
- some is used to break down food.
Photosynthesis occurs in the chloroplasts
located in the palisade layer of the leaf.
Importance of Photosynthesis
1. Provides food for almost all of the
consumers on Earth.
2. Provides oxygen (90%) for organisms
and removes carbon dioxide from the
atmosphere.
RESPIRATION
- the process used to break down
food into energy.
- it also occurs in plants.
C6H12O6 + 6O2
6CO2 + 6H2O + energy
- it occurs in the cell’s mitochondria.
- respiration’s energy is used to
build and repair cells and tissues.
Photosynthesis’ and respiration’s raw
materials are “linked together”:
Worksheet
“Photosynthesis and Respiration”
PLANT RESPONSES
- the response of a
plant to a stimulus
is a tropism.
p.312
1) Thigmotropism
- when touched, a
plant ‘closes’ its
leaves. (p. 311)
Ex. Venus Flytrap
ASSIGNMMENT:
WORKSHEET:
“PHOTOSYNTHESIS & RESPIRATION”
QUESTIONS
P. 296 8,13,17
P. 322 11,13,14,17
2) Phototropism
- the plant grows
towards light.
3) Geotropism or
Gravitropism
- the plant roots
grow downward…
- stems grow
upward.
- in response to
gravity.
Tropisms are controlled by plant
hormones called auxins.
Ex. for phototropism,
the auxins move to
the ‘shady’ side of
the stem.
- the auxins create
more growth on
that side causing
the stem to bend
into the light.
Photoperiodism
- a flowering response
to the changes in the
amount of daylight.
- plants need a certain
amount of darkness
to flower.
Long-day Plants
- need short
nights to flower.
Ex. zinnias,
potatoes
Day-neutral Plants
- can flower over
a wide range of
night lengths.
Ex. marigolds,
corn.
Short-day Plants
- need long
nights to flower.
Ex. poinsettia
Photoperiodism ensures there are
lots of pollinators when the plant
flowers - less ‘competition’.
ASSIGNMENT:
WORKSHEET
“PLANT PROCESSES”
Seed Germination
(p. 290)
- when a seed sprouts.
- conditions must be right
- moisture/warm temps.
- if not, the seed remains
‘dormant’ waiting for good
conditions.
The plant uses the food stored in the
cotyledon until photosynthesis can
begin. (p. 291).
Asexual Reproduction
- only one parent necessary.
A) Natural
- some plants produce
“runners”.
- where it touches the
ground, a new plant is
formed.
Ex. strawberry
B) Grafting
- attaching part of one
plant to another.
Grafting is commonly done with trees taking the best traits and combining
them together.
Ex. orange tree
Very hardy
Weak - intolerant
Sour fruit
Sweet fruit
C) Water propagation
ASSIGNMENT:
WORKSHEET
“CHAPTER REVIEW”