Transcript Plants & Photosynthesis - Dr. Annette M. Parrott

Plants &
Photosynthesis
A Dr.
Production
Why Study Plants?
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Oxygen can you breathe?
Ozonedo you tan, burn or melanoma?
Carbohydrates do you have food to eat?
Fiber are you regular?
Wood where do you live
Fossil fuels do you drive or stay warm in the winter?
Latex ever use plastic?
Medicinesever get sick?
Pitch do you like your furniture varnished & painted?
Resins ever float a boat?
Flavors & fragrancesdo you like tasteful aromatic food?
Jobs…
Careers in Horticulture:
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Pomology-fruits
Viticulture-grapes
Enology-wine
Olericulture-vegetables
Ornamental Horticulturelandscape plants
• Landscape Architecturedesign
1. Vascular tissue?
No…………Bryophyte
Yes………..Tracheophyte, go to 2
2. Seeds?
No…………Seedless plant
Yes………..Seed plant, go to 3
3. Covered Seeds?
No…………Gymnosperm
Yes………..Angiosperm, go to 4
4a. One cotyledon, parallel veins, 3X flowers, 1 pore
pollen, scattered vascular bundles, fibrous roots
Yes……….……monocot
4b. Two cotyledons, netted veins, 4X/5X flowers, >3
pored pollen, ringed vascular bundles, taproots
Yes………..…..dicot
What types of plants are there?
Alternation of Generations
• Plants (as all sexually reproducing organisms) spend
part of their life haploid (gametophyte) and part of
their life diploid (sporophyte).
Avascular Plants : Mosses, Hornworts &
Liverworts
Life Cycle
of a Moss
Seedless Vascular Plants : Ferns, Club mosses,
Horsetails and Whisk ferns
Ferns are seedless plants whose flagellated sperm
require moisture to reach the egg
The life cycle of a fern
Figure 29.11xa Life cycle of a fern: mature fern (diploid sporophyte)
Life cycle of a fern: gametophyte
Seedless plants formed vast “coal forests”
• Ferns and other seedless plants once dominated
ancient forests
– Their remains formed coal
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Female gametophyte (n)
Haploid spore cells in
ovule develop into
female gametophyte,
which makes egg.
5 Male gametophyte (pollen)
Egg (n)
grows tube to egg and
makes and releases sperm.
Sperm (n)
Male gametophyte
(pollen grain)
HAPLOID
DIPLOID
MEIOSIS
Ovule
Fertilization
Scale
Sporangium
(2n)
Seed
coat
3 Pollination
HAPLOID
Pollen grains
(male
gametophytes)
(n)
Embryo
(2n)
Integument
1 Female cone
bears ovules.
6 Zygote develops
MEIOSIS
into embryo, and
ovule becomes
seed.
2 Male cone produces
spores by meiosis;
spores develop into
pollen grains
Zygote
(2n)
7
Sporophyte
Seed
Seed falls to
ground and germinates,
and embryo grows into tree.
Life Cycle of a Gymnosperm
2 Haploid spore in each
Stigma
Egg (n)
ovule develops into
female gametophyte,
which produces egg.
3 Pollination
Pollen
grain
and
growth
of pollen
tube
Ovule
Pollen
tube
1 Haploid spores
in anthers develop
into pollen grains:
male gametophytes.
Sperm
Pollen (n)
HAPLOID
Meiosis
Fertilization
DIPLOID
4
Zygote
(2n)
Food supply
Seed
coat
Seeds
7 Seed
Ovary
germinates,
and embryo
grows into plant.
Ovule
Sporophyte
6 Fruit
Life Cycle of an Angiosperm
5 Seed
Embryo
(2n)
Bryophytes
Seedless Plants
Tracheophytes
Gymnosperms
Angiosperms
What is it?
1.
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5.
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What is Photosynthesis?
Photosynthesis is using light energy from the
sun to make sugar
Light E + CO2 + H2O  C6H12O6 + O2
Photosynthesis occurs in the chloroplasts
of autotrophs
Light Reactions occur in the thylakoid
membrane of the chloroplast
Light reactions use light energy and water to
produce:
ATP
Hydrogen (NADPH)
Oxygen (as waste)
The dark reactions are also called the
Calvin Cycle or Carbon Fixation
Dark reactions occur in the stroma of the
chloroplasts
They use energy to store it in the form of a
sugar for later use
Special plants called C4 plants, or CAM
plants have specialized systems of
photosynthesis
CAM.qt
Leaf Anatomy
derm
LeafWeb qt
Anatomy
Opening & Closing of Stomata
Stem Anatomy
Transport through Vascular Tissue
• Xylem Wxyz Water
• Phloem phood by photosynthesis
FoodWeb qt
Source & Sink
Water&PlantsWebqt
Water movement
Root Anatomy
Root Anatomy
Flowers
• The flower is the centerpiece of angiosperm
reproduction
Pollen grains
Anther
• Double Fertilization
Stigma
CARPEL
Ovary
STAMEN
PETAL
Ovule
SEPAL
Fruit
• After fertilization the ovary matures into a
fruit. In general fruits may be classified as
simple, aggregate or multiple ).
• Angiosperm fruit has 2 functions:
1. Protect the seeds during their maturation
2. Effectively disperse the mature seeds
ripening.qt
Tomatoes
seed.qt
The structure of a fruit reflects its function in
seed dispersal
• Fruits are adaptations that disperse seeds
Seeds
With double fertilization the following occurs:
1. The zygote develops into an embryo
2. The integuments develop into a seed coat
3. The ovary develops into a fruit
4. The primary endosperm nucleus divides
to form endosperm
Germin.qt
Maizegr.qt
Geotropism
Maizepho.qt
Geotropism
Plant Responses (Tropisms)
Tropisms vs Taxisms
Thigmotropism Physical Contact.
Thermotropism Temperature
Electrotropism Electricity
Aerotropism Oxygen
Phototropism light
Plants in Motion
Tropisms
Mimosa, Sundew
Chemotropism Chemicals
Traumotropism Wounding
Skototropism Dark
Gravitropism Gravity
Plants Can Tell Time
• Circadian Rhythms
Sleep Movements in
Legume
Silk Tree
Plant Defenses
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Physical thorns, spines, hairs
Chemical poisons, irritants, medicines
Ingestibilitycellulose
Mechanical thigmotropism
• Systemic Defense Against Herbivores
Plant Hormones
Hormone: a chemical substance effective in small
quantities, that is produced one place and has its effects
elsewhere
• Auxinsroot formation, apical dominance
• Giberellins seed germination, stem elongation
• Cytokinins cell division, differentiation
• Abscisic Acid ab secare plant maturation, leaf
abscission (what time of year?)
• Ethylene  leaf abscission, one bad apple…
Cucumber
Cytokinins
Strawberry
Ripening
Agriculture is based almost entirely on
angiosperms
• Gymnosperms supply most of our lumber and
paper
• Angiosperms provide most of our food
– Fruits, vegetables, and grains
• Angiosperms also provide other important
products
– Medications, fiber, perfumes
Interactions with animals profoundly influenced
angiosperm evolution (Coevolution)
• Angiosperms are a major source of food for
animals
– Animals also aid plants in pollination and seed
dispersal
Connection: Plant diversity is a
nonrenewable resource
• 20% of the tropical forests worldwide were
destroyed in the last third of the 20th century
• The forests of North America have shrunk by
almost 40% in the last 200 years
• Some plants in these forests can be used in
medicinal ways
– More than
25% of
prescription
drugs are
extracted
from plants
References
• Plant Anatomy: BIO 102
• http://generalhorticulture.tamu.edu/HORT604/LectureSuppl/Anatomy
Organs/AnatomyOrgans05.htm
• Plants in Motion Movies:
• The Life Wire Textbook Animations
• Biology I Tutor Vista Animations
• Plant Curriculum Links
• 4 Types of Plants Video
• The World of Plants: Plants & People Video
• Science of Life; The World of Plants
• Tour of a Plant Cell Study Guide