Why Study Plants?• Oxygen can you breathe?
• Ozonedo 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?
• Medicinesever get sick?
• Pitch do you like your furniture varnished & painted?
• Resins ever float a boat?
• Flavors & fragrancesdo you like tasteful aromatic food?
• Jobs…
Careers in Horticulture:
• Pomology-fruits• Viticulture-grapes• Enology-wine• Olericulture-vegetables• Ornamental Horticulture-
landscape plants• Landscape Architecture-
design
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 : Avascular Plants : Mosses, Hornworts & , Hornworts & LiverwortsLiverworts
Life Cycle of a Moss
Seedless Vascular Plants : Seedless Vascular Plants : Ferns, Club mosses, , Club mosses, HorsetailsHorsetails and Whisk ferns and Whisk ferns
Ferns are seedless plants whose flagellated sperm require moisture to reach the egg
• Ferns and other seedless plants once dominated ancient forests– Their remains formed coal
Seedless plants formed vast “coal forests”
Egg (n)
1
HAPLOIDDIPLOID
Sperm (n)
Male gametophyte(pollen grain)
Female gametophyte (n)
Zygote(2n)
Seedcoat
Embryo(2n)
Seed
Sporophyte
Scale
Sporangium(2n)
Ovule
Integument
MEIOSIS
HAPLOIDPollen grains(malegametophytes)(n)
MEIOSIS Fertilization
Female conebears ovules.
2 Male cone producesspores by meiosis;spores develop intopollen grains
3 Pollination
4 Haploid spore cells inovule develop intofemale gametophyte,which makes egg. 5 Male gametophyte (pollen)
grows tube to egg andmakes and releases sperm.
6 Zygote developsinto embryo, andovule becomesseed.
7 Seed falls toground and germinates,and embryo grows into tree.
Life Cycle of a Gymnosperm
HAPLOID
DIPLOID
Egg (n)
Ovule
Stigma
Pollengrain
Pollentube
Sperm
Fertilization
Seedcoat
Embryo(2n)
Seeds
Sporophyte
Ovary
Ovule
Pollen (n)
Meiosis
1 Haploid sporesin anthers develop
into pollen grains: male gametophytes.
2 Haploid spore in eachovule develops intofemale gametophyte,which produces egg.
3 Pollinationandgrowthof pollentube
4 Zygote(2n)
5 Seed
6 Fruit
7 Seed germinates,
and embryo grows into plant.
Food supply
Life Cycle of an Angiosperm
Bryophytes
Tracheophytes
Seedless Plants GymnospermsAngiosperms
What is it?
1. 6.
2. 7.
3. 8.
4. 9.
5. 10.
What is Photosynthesis?
Photosynthesis is using light energy from the sun to make sugar
Light E + CO2 + H2O C6H12O6 + O2
Light Reactions occur in the thylakoid membrane of the chloroplast
Special plants called C4 plants, or CAM plants have specialized systems of photosynthesis
CAM.qt
Opening & Closing of Stomata
Transport through Vascular Tissue• Xylem Wxyz Water
• Phloem phood by photosynthesis
FoodWeb qt Source & Sink
Water&PlantsWebqt Water movement
Flowers
• The flower is the centerpiece of angiosperm reproduction
• Double Fertilization
STAMEN
Anther
Pollen grains
Stigma
Ovary
CARPEL
PETAL
SEPALOvule
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 maturation2. Effectively disperse the mature seeds
ripening.qt Tomatoes
seed.qt
• Fruits are adaptations that disperse seeds
The structure of a fruit reflects its function in seed dispersal
SeedsWith double fertilization the following occurs:
1. The zygote develops into an embryo2. The integuments develop into a seed coat 3. The ovary develops into a fruit4. 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. Chemotropism Chemicals Thermotropism Temperature Traumotropism Wounding Electrotropism Electricity Skototropism Dark Aerotropism Oxygen Gravitropism GravityPhototropisml t igh
Plants in MotionTropisms
Mimosa, Sundew
Plants Can Tell Time
• Circadian Rhythms
Silk Tree
Sleep Movements in Legume
Plant Defenses
• Physical thorns, spines, hairs
• Chemical poisons, irritants, medicines
• Ingestibilitycellulose
• Mechanical thigmotropism
• Systemic Defense Against Herbivores
Plant HormonesHormone: a chemical substance effective in small
quantities, that is produced one place and has its effects elsewhere
• Auxinsroot 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
• 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
Agriculture is based almost entirely on angiosperms
• Angiosperms are a major source of food for animals– Animals also aid plants in pollination and seed
dispersal
Interactions with animals profoundly influenced angiosperm evolution (Coevolution)
• 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
Connection: Plant diversity is a nonrenewable resource
• 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/AnatomyOrgans/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