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Lab #7 Roots, Stems and Leaves
Lab #7
Roots, Stems and Leaves
Chloroplasts
Plastids
Amyloplasts – from garden bean
chromoplasts – from red pepper
Parenchyma tissue
spongy
palisade
Collenchyma
collenchyma
sclerenchyma
collenchyma
parenchyma
Sclerenchyma
Epidermis & Guard cells
Epidermal structures
Guards cells + Stoma
Trichome and leaf cross section
protoxylem
metaxylem
VE
Tracheids
metaxylem
Xylem
metaxylem
protoxylem phloem
WATER-CONDUCTING CELLS OF THE XYLEM
Tracheids
Pits
Tracheidswith circular-bordered pitsin their primary walls TRACHEIDS
from Biology 311 site Alison Roberts ([email protected]) © 1998-2012 AWR
Tracheids with annular thickenings
from Biology 311 site Alison Roberts ([email protected]) © 1998-2012 AWR
tracheids
perforation plates in the side walls of a vessel element
vessel elementswith perforation plates
VESSEL ELEMENTS
tracheidsvessel elements
alignedperforationplates
Tracheids vs. Vessel
Elements
tracheidsvessel elements
vessel elements
tracheids
most angiosperm xylem containsvessel elements
Vessel Elements
VE
VE
VEVE
protoxylem
metaxylem
Phloem
sieve elements
Phloem
Phloem
http://www.sbs.utexas.edu/mauseth/weblab/webchap8phloem/chapter_8.htm
companion cell
companion cell
companion cell
companion cell
companion cell
sieve tubemembers
sieve plate
Phloem
sieve plate
http://www.sbs.utexas.edu/mauseth/weblab/webchap8phloem/chapter_8.htm
Leaf tissues
vascular bundles
Mesophyll – Palisade and Spongy
spongy
palisade
epidermis
epidermis
Pine needles
Apical meristem
apical meristem
axillary bud
developingvascular tissue
developing leaf primordia subapical
meristem
apical meristem
Root Meristems
RootApicalmeristem
Root cap
RootApicalmeristem
Root cap
Monocot Stems
Monocot stemsepidermis
parenchyma
cortex
Monocot Stem Vascular Bundle
xylem
sclerenchyma is called a bundle sheath inmonocot leaf vascular bundles
sclerenchyma
phloem
metaphloem
protoxylem
metaxylem
No vascular cambium – no secondary growth!
Monocot Leaf
Monocot leaves
monocot leafvein
monocot leafveins
Monocot Roots
Phloem
Xylem
Pericycle
Core ofparenchymacells
Endodermis
Monocot Root
http://www2.mcdaniel.edu/Biology/botf99/rootuse/monovsdi.htm
pith
xylem(vessel element& tracheids)
phloem
pericycle
pith
Monocot root
xylem(vessel element& tracheids)
phloem
pericycle
endodermis
pith
Dicot Stems
MedullaryRays
Dicot stems
from Biology 311 site Alison Roberts ([email protected]) © 1998-2012 AWR
Helianthus (sunflower)
phloem
metaxylem
protoxylem
vascularcambium
Trifolium (clover)
epidermis
cortex
pith
Dicot Stem
interfasicularcambium
fasicularcambium
sclerenchyma
xylem
pith
phloem
Dicot Stem Vascular Bundle
sclerenchyma
tracheids
region ofprotoxylem
region ofmetaxylem vessel
elements
Monocot vs. Dicot Stem
DICOTMONOCOT
Dicot vs. Monocot Vascular Bundles
from Biology 311 site Alison Roberts ([email protected]) © 1998-2012 AWR
DICOT
sclerenchyma
tracheid
phloem
vascularcambium
protoxylemmetaxylem
VE VEVE
sclerenchyma
MONOCOT
Sclerenchyma
tracheid
VE
VE
Dicot Leaves
collenchyma
Dicot leaf veins
Dicot Leaf
Stained cross-section through the leaf of lilac: 1 upper epidermis, 2 palisade parenchyma, 3 spongy parenchyma, 4 air cavity, 5 lower epidermis, 6 stomata, 7 trichome, 8 major vein, 9 xylem, 10 phloem, 11 supporting tissue (sclerenchyma)http://www.vcbio.science.ru.nl/en/virtuallessons/leaf/mesomorph/
Key
DermalGroundVascular
Epidermis
Cortex
Vascular cylinder
Transverse section of a typical root. In the roots of typical gymnosperms and eudicots, as well as some monocots, the stele is a vascular cylinder consisting of a lobed core of xylem with phloem between the lobes.
100 µm
Endodermis
Core ofparenchymacells
Pericycle
Xylem
Phloem
Endodermis
Pericycle
Xylem
Phloem
50 µm
Dicot Roots
endodermis
Dicot Roots
Dicot Root
metaxylem
vascular cylinder = stele
from Biology 311 site Alison Roberts ([email protected]) © 1998-2012 AWR
phloem
pericycle
endodermis
VE VE
VE
Dicot vs. Monocot Root
Dicot Lateral Root
Secondary growth
Secondary growth
Secondary growth
Secondary growth:Stems vs. Roots
tracheids
xylem rayvessel element
perforationplate
perforation plate: the end of a vessel element w
Ash wood
from Biology 311 site Alison Roberts ([email protected]) © 1998-2012 AWR
perforationplate
http://www.sbs.utexas.edu/mauseth/weblab/webchap7xylem/chapter_7.htm
Oak
Vessel element
http://www.sbs.utexas.edu/mauseth/weblab/webchap7xylem/chapter_7.htm
tracheids
vessel elements
from Biology 311 site Alison Roberts ([email protected]) © 1998-2012 AWR
3 yr Tilia stem (Basswood)
pits
perforationplates
from Biology 311 site Alison Roberts ([email protected]) © 1998-2012 AWR
3 yr Tilia stem (Basswood)
3 yr Tilia stem (Basswood)
secondary xylem(tracheids &vessel elements)
secondary xylem(tracheids &vessel elements)
secondary xylem(tracheids &vessel elements)
vascularcambium
secondaryphloem
cork
corkcambium
cork + cork cambium = Peridermvascular cambium to cork = Bark
annual ring
annual ring
annual ring
axial system of wood(tracheids & vessel elements)
small arrows = vesselelements
Ilex opaca (American holly, a dicot or hardwood)
NOT A CONIFER LIKE A PINE!!(has vessel elements)
American Holly
http://www.sbs.utexas.edu/mauseth/weblab/webchap15wood/chapter_15.htm
White pine
http://www.sbs.utexas.edu/mauseth/weblab/webchap15wood/chapter_15.htm
axial system of wood(tracheids)
tracheids of springwood
tracheids of summerwood
annual ring
Soft wood = no vesselelements!!
White Pine
tracheids of springwood
tracheids of summerwood
circular bordered pit between two tracheids
http://www.sbs.utexas.edu/mauseth/weblab/webchap15wood/chapter_15.htm
White Pine
tracheids of a xylem ray
http://www.sbs.utexas.edu/mauseth/weblab/webchap15wood/chapter_15.htm
Cork Cambium
cork cambium
cork
from Biology 311 site Alison Roberts ([email protected]) © 1998-2012 AWR
lenticel
