function shapes structure… structure enables function what functions and structures exist? those...
TRANSCRIPT
Function shapes structure…Structure enables function
What functions and structures exist? Those passed on by past generations… Evolution
Plants grow and reproduce, as well as, respond to the environment.
CB 35.2
Plants grow and reproduce, respond to the environment… today- transport
CB 35.9
Types of Plant Cells:defined by function and cell wall
CB 6.9
CB 35.9
60 m
Parenchyma cells- most common cells; primary cell walls
CB 35.16
Parenchyma in a stem
CB35.9
Collenchyma cells- unevenly thickened cell walls; flexible support
80 m
Collenchyma in a leaf
CB 35.9
Sclerenchyma cells- Thickened secondary walls (inside primary wall); with lignin; rigid
5 m
25 m
CB 35.9
Water conducting cells of Xylem:
vesselsand
tracheids(types of sclerenchyma)
100 m
Sugar conducting cells of Phloem: sieve-tubes and companion cells
15 m
30 m
CB 35.9
CB 35.18
Plants transport water, sugar, minerals, hormones, etc through the vascular system comprised of xylem and phloem
CB 36.2
Water travels from ground out through stomata via xylem
CB 36.2
The exit of water through stomata is accompanied by gas exchange
CB 36.2
Sunlight powers photosynthesis and these sugars are transported via phloem
The direction of Phloem transport is versatile.
CB 36.8
Plant cell to cell transport can occur by two pathways: symp[lastic and apoplastic
plasmodesmata
CB 36.17
Sugar is loaded at sources and unloaded at sinks
CB 36.18
Sugar is loaded at sources and unloaded at sinks
source:leaf
sink:root, flower, emerging leaf etc…
CB 35.18
Plants transport water, sugar, minerals, hormones…
CB 36.7
Much of plant support comes from turgor pressure.
CB 36.13
Water moves from the ground through roots into the shoot and out stomata in the leaves.
CB 35.12 and .13
In roots the vascular bundle is in the center
CB 36.9
The casparian strip of the endodermis keeps water from entering the xylem via a purely apoplastic route.
CB 36.13
What moves the water through the xylem?
CB 35.17
Stomata control entry of CO2 and exit of H2O from plant leaves
Stomata
CB 36.12
Stomata on the underside of a leaf
CB 36.15
Guard cell opening is regulated by turgor
CB 36.13
What moves the water through the xylem?Transpiration, Adhesion, Cohesion, andTension
water transport limits plant growth
xylem
phloem
More xylem is needed for more water transport: secondary growth
xylem
phloem
Xylem is tough, and full of lignin- inhibits the ability to use plants to produce biofuels