2006-2007 AP Biology Plant Anatomy Chapter 35
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
2006-2007 AP Biology
Plant AnatomyChapter 35
AP Biology
Basic plant anatomy 1 root
root tip root hairs
AP Biology
Roots Roots anchor plant in soil, absorb
minerals & water, & store food fibrous roots (1)
mat of thin roots that spread out monocots
tap roots (2) 1 large vertical root also produces many small lateral,
or branch roots dicots
root hairs (3) increase absorptive
surface area
2
1
3
AP Biology
Basic plant anatomy 2 root
- fungi at tips of the roots Mycorrhizae
- -Symbiotic relationship
shoot (stem) buds
terminal or apical buds-located at the top
axillary buds-located at the V formed b/t leaf and stem
AP Biology
Modified shootsstolons (strawberries) rhizome (ginger)
tuber (potato) bulb (onion)
AP Biology
Leaves Function of leaves
photosynthesis energy production CHO production
gas exchange transpiration simple vs. compound
AP Biology
AP Biology
Putting it all together Obtaining raw materials
sunlight leaves = solar collectors
CO2
stomates = gas exchange
H2O uptake from roots
nutrients uptake from roots
AP Biology
Plant TISSUES Dermal
epidermis (“skin” of plant) single layer of tightly
packed cells that covers & protects plant
Ground bulk of plant tissue photosynthetic mesophyll,
storage Vascular
transport system in shoots & roots
xylem & phloem
AP Biology
Plant CELL types in plant tissues Parenchyma
“typical” plant cells = least specialized photosynthetic cells, storage cells tissue of leaves, stem, fruit, storage roots
Collenchyma unevenly thickened primary walls support
Sclerenchyma very thick, “woody” secondary walls support rigid cells that can’t elongate dead at functional maturity
If I’d onlyhad triplets!
AP Biology
Xylem and PhloemXylem- water conducting cells.
xylem vessels- found mostly in angiosperms have pits for water movement.
xylem tracheids- long thin cells strengthen with lignin
AP Biologytracheids
vessel elements Vascular tissue
Aaaah…Structure–Function
again!
vessel element
dead cells
Xylem move water & minerals up from roots dead cells at functional maturity
only cell walls remain need empty pipes to efficiently move H2O transpirational pull
AP Biology
Phloem: food-conducting cells carry sugars & nutrients throughout plant
sieve tube
companion cell
living cells
plasmodesmata sieve plate
AP Biology
Phloem: food-conducting cells sieve tube elements & companion cells
AP Biology
Phloem Living cells at functional maturity
cell membrane, cytoplasm control of diffusion
lose their nucleus, ribosomes & vacuole more room for specialized transport of
liquid food (sucrose)
Cells sieve tubes
sieve plates — end walls — have pores to facilitate flow of fluid between cells
companion cells nucleated cells connected to the sieve-tube help sieve tubes
Aaaah…Structure–Function
again!
2006-2007 AP Biology
Plant GrowthChapter 35
AP Biology
Life Cycle of Plants Annuals- in one year Ex:Wildflowers,
crops Biennials- completed in 2 years Ex:
radishes and carrots Perennials- continues for many years
Ex. Trees
AP Biology
Growth in Plants Specific regions of growth: meristems
stem cells: perpetually embryonic tissue regenerate new cells
apical shoot meristem growth in length primary growth
apical root meristem growth in length primary growth
lateral meristem growth in girth secondary growth
AP Biology
Apical meristems
shoot root
AP Biology
Root structure & growth
protecting the meristem
AP Biology
Shoot growth
Young leafprimordium
Apical meristem
Older leafprimordium
Lateral budprimordium
Vascular tissue
protecting the meristem
AP Biology
Woody plants grow in height from tip
primary growth apical meristem
Woody plants grow in diameter from sides
secondary growth lateral meristems
vascular cambium makes 2° phloem & 2° xylem
cork cambium makes bark
Growth in woody plants
Primaryphloem Primary
xylemSecondaryphloem
Secondaryxylem
Annualgrowthlayers
Lateralmeristems
Primaryxylem
Primaryphloem
Bark
Epidermis
AP Biology
Vascular cambium
last year’s xylemearly
late
phloem
bark
Phloem produced to the outside Xylem produced to the inside
corkcambium
vascularcambium
xylem
Why are early & late growth
different?
AP Biology
Woody stem cork cambium
vascular cambium
xylem
earlylate
phloem bark
How old is this tree?
12
3
AP Biology
Secondary Growth produced by the vascular cambium
Vascular cambium Growth
Secondaryxylem
After one yearof growth
After two yearsof growth
Secondaryphloem
VascularcambiumX X
X X
X
X
P P
P
P
C
C
C
C
C
C
C C C
C C
CC
AP Biology
Plant hormones Ch:39 auxin gibberellins abscisic acid ethylene and more…
AP Biology
Auxin (IAA) Effects
controls cell division & differentiation
phototropism growth towards light asymmetrical distribution of auxin cells on darker side elongate faster
than cells on brighter side apical dominance
AP Biology
Gibberellins Family of hormones
over 100 different gibberellins identified
Effects stem elongation fruit growth seed germination
plump grapes in grocery stores have been treated with gibberellin hormones while on the vine
AP Biology
Abscisic acid (ABA) Effects
slows growth seed dormancy
high concentrations of abscisic acid germination only after ABA is inactivated or
leeched out
survival value: seed will germinate only under optimal conditions
light, temperature, moisture
AP Biology
Ethylene Hormone gas released by plant cells Effects
fruit ripening leaf drop
like in Autumn apoptosis
One bad apple spoils the
whole bunch…
AP Biology
Fruit ripening Adaptation
hard, tart fruit protects developing seed from herbivores
ripe, sweet, soft fruit attracts animals to disperse seed
Mechanism triggers ripening process
breakdown of cell wall softening
conversion of starch to sugar sweetening
positive feedback system ethylene triggers ripening ripening stimulates more ethylene production
AP Biology
Apoptosis in plantsWhat is the evolutionary advantage of loss of leaves in autumn?
Many events in plants involve apoptosis
response to hormones ethylene auxin
death of annual plant after flowering
senescence differentiation of xylem vessels
loss of cytoplasm shedding of autumn leaves
2006-2007 AP Biology
Don’t take this lying down…
Ask Questions!!
Related Documents
