Download Exam #2 M (3/9) 7:30

Exam #2 M (3/9) 7:30-9pm in BUR 106
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.
Plants grow and reproduce, respond to the
environment… today- transport
Types of Plant
Cells:
defined by
function and
cell wall
Plant cell walls are mostly made of cellulose
Fig 7.6
Cell walls contain cellulose, pectins, proteins...
Fig 8.3
Parenchyma cells- most common cells;
primary cell walls
Fig 36.22
60 m
Parenchyma in a
stem
Fig 36.18
Collenchyma cells- unevenly thickened cell
walls; flexible support
Fig
36.24
80 m
Collenchyma in a leaf
Sclerenchyma cells- Thickened secondary
walls (inside primary wall); with lignin; rigid
5 m
Fig 36.25
25 m
Water conducting
cells of Xylem:
vessels
and
tracheids
(types of sclerenchyma)
Fig 36.26
100 m
Sugar conducting cells of
Phloem: sieve-tubes and
companion cells
Fig 36.27
30 m
15 m
Fig 36.2
Plants transport
water, sugar,
minerals, hormones,
etc through the
vascular system
comprised of xylem
and phloem
Fig 37.4
Water travels
from ground out
through stomata
via xylem
Fig 37.4
The exit of water
through stomata
is accompanied
by gas exchange
Fig 37.17
Sunlight powers
photosynthesis
and these sugars
are transported
via phloem
Fig 37.18
Phloem
transport is
from source
to sink.
Fig 37.20
Sugar is
loaded at
sources
and
unloaded
at sinks...
source:
consuming
ATP
sink:
leaf
root,
flower,
emerging
leaf etc…
Fig 37.18
Source and
sink locations
vary...
The direction of
Phloem transport is
versatile.
Plants transport
water, sugar,
minerals,
hormones…
Fig 37.5
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.
Fig 37.7
In roots the
vascular bundle
is in the center
Plant cell to cell transport can occur by two
pathways: symplastic and apoplastic
Fig 37.8
plasmodesmata
Fig 37.8
The casparian strip of
the endodermis keeps
water from entering
the xylem via a
purely apoplastic
route.
What moves the
water through the
xylem?
Stomata
control entry
of CO2 and exit
of H2O from
plant leaves
Fig 10.21
Stomata
Stomata on the underside of a leaf
Fig 36.20
Guard cell
opening is
regulated by
turgor
Fig 37.4+.11
What moves the
water through the
xylem?
Transpiration,
Adhesion,
Cohesion, and
Tension
water transport
limits plant growth
More xylem is needed for more water
transport: secondary growth
phloem
xylem
Xylem is tough, and full of lignin- inhibits
the ability to use plants to produce biofuels
phloem
xylem
Exam #2 M
(3/9) 7:30-9pm
in BUR 106
(bring cheat sheet)