BIOLOGY 322

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BIOLOGY 322 STRUCTURE, PHYSIOLOGY AND
REPRODUCTION OF SEED PLANTS Prof. John W. La
Claire BIO 325 471-3577 laclaire_at_uts.cc.utexas.edu
course website http//www.sbs.utexas.edu/bio322
/
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• INTRODUCTION
• Constraints on Land Plants
• Uniqueness of Plants
• Autotrophy
• Stationary (Sessile)
• 1. Ramifications

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gaseous

• CONSEQUENCES
• easy to grow through
• lots of gases (O2 CO2)
• lots of sunlight
• not physically supportive
• little water available

shoot

• difficult to grow through
• abrasive
• good physical support
• source of water and minerals

root
(alternatives epiphytes parasitic plants)
solid
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ENERGY CARBON absolutely required for life
UNIQUENESS OF PLANTS 1. AUTOTROPHIC
(self-feeding) energy light energy from
sun carbon CO2 (inorganic form)
PHOTOSYNTHESIS
light essentially CO2 H2O ????? CH2O O2?
(many rxns.)
first product glyceraldehyde 3-phosphate (3-phosp
hoglyceraldehyde)
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mycorrhizal fungus
require MORE than light CO2 ( H2O) Minerals
naturally-occurring inorganic elements/compoun
ds must acquire 1) directly from soil (most)
from weathering of parent rock 2) indirectly
- symbiotic organisms
bacterial root nodules
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UNIQUENESS OF PLANTS 2. STATIONARY sessile, do
not move around much can only GROW to another
place
STRESSES 1. PHYSIOLOGICAL A. water (daily,
seasonal, long-term) B. minerals (salty soils
turgor problems, contaminated soils, serpentine
soils) C. temperature (daily, seasonal,
long-term) D. light (sun- vs. shade-loving) E.
pathogens herbivores (no immune system per
se, but mechanical/chemical defense systems)
2. SEXUAL REPRODUCTION need to find mates for
outbreeding 3. DISPERSING SPORES OFFSPRING
(seeds, fruits) dont want offspring overgrowing
parent 4. COMPETITION for light, minerals,
water, etc. involves GROWTH TRANSPORT
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Topics we will cover ( carry out lab experiments
on) 1. mineral nutrition 2. growth and
development 3. water and solute transport 4.
photosynthesis ALL CRITICAL TO PLANTS UNIQUE
PROCESSES OR WAYS OF PERFORMING ALL OF THESE!