23 plants1 - uvm.edu
TRANSCRIPT
10/30/21
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Being Multicellular
• Being Multicellular – Division of labor – Self- vs non-self – Communication & Coordination – Bulk transport
• Plant structure – Meristems and primary growth – Tissue systems – Stem structure – Roots
November 1, 2021
Brief history of life
Cells of this colonial alga are connected, but it is not truly multicellular
Volvox
What is needed for true multicellularity?
Specialization of different cell types
Recognize Self vs Other
http://www.scielo.br/scielo.php?pid=S1982-56762008000500007&script=sci_arttext
Communication between cells
Animals cells can have gap junctions
Plant cells have plasmodesmata
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Bulk Transport Animals and Plants develop differently
Plant cells can’t move, so all growth is from meristems
Animal cells can migrate
Plant shoots are made from repeating modules: Stem, Leaf, Bud
http://www.uwgb.edu/biodiversity/herbarium/trees/node_internode01web_gf.jpg
Plants have Indeterminate Growth
Shoot apical meristem
Young leaf
Developing vascular strand
Axillary bud meristems
0.25 mm
Primary Shoot Growth
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Epidermis Ground Vascular
Stem structure
Monocot
Eudicot
Vessel element
Pits
Vessel Tracheids 100 µm
Vascular Tissue
Roots Ground
Dermal
Key to labels
Vascular
Root hair
Epidermis
Cortex Vascular cylinder
Zone of differentiation
Zone of elongation
Zone of cell division
Apical meristem
Root cap
100 µm
Roots
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Root structure
Monocot Dicot
Roots