Chapter 34: The Plant Body
CHAPTER 34
The Plant Body
Chapter 34: The Plant Body
Chapter 34: The Plant Body
Vegetative Organs of the Flowering Plant Body
Plant Cells
Plant Tissues and Tissue Systems
Forming the Plant Body
Leaf Anatomy Supports Photosynthesis
Chapter 34: The Plant Body
Vegetative Organs of the
Flowering Plant Body
• Monocots typically have a single cotyledon,
narrow leaves with parallel veins, flower
parts in threes or multiples of three, and
stems with scattered vascular bundles.
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Chapter 34: The Plant Body
Vegetative Organs of the
Flowering Plant Body
• Eudicots typically have two cotyledons,
broad leaves with netlike veins, flower parts
in fours or fives, and vascular bundles in a
ring.
• Flowering plants that are neither monocots
nor eudicots are generally similar in
structure to eudicots.
Review Figure 34.1
4
Chapter 34: The Plant Body
figure 34-01.jpg
Figure
34.1
Figure 34.1
Chapter 34: The Plant Body
Vegetative Organs of the
Flowering Plant Body
• The vegetative organs of flowering plants
are
roots, which form a root system,
 stems and
 leaves, which form a shoot system.

Review Figure 34.2
6
Chapter 34: The Plant Body
figure 34-02.jpg
Figure 34.2
Figure 34.2
Chapter 34: The Plant Body
Vegetative Organs of the
Flowering Plant Body
• Roots anchor the plant and take up water
and minerals.
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Chapter 34: The Plant Body
Vegetative Organs of the
Flowering Plant Body
• Stems bear leaves and buds.
Lateral buds form branches.
 Apical buds produce cells that
contribute to stem elongation.

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Chapter 34: The Plant Body
Vegetative Organs of the
Flowering Plant Body
• Leaves are responsible for most
photosynthesis
• their flat blades, oriented perpendicular to
the sun’s rays, are well adapted.
Review Figure 34.5
10
Chapter 34: The Plant Body
figure 34-05.jpg
Figure 34.5
Figure 34.5
Chapter 34: The Plant Body
Plant Cells
• Plant cell walls have a structure that often
corresponds to special functions of the cell.
• Walls of individual cells are separated by a
middle lamella common to two neighboring
cells; each cell has its own primary wall.
Review Figure 34.6
12
Chapter 34: The Plant Body
figure 34-06.jpg
Figure 34.6
Figure 34.6
Chapter 34: The Plant Body
Plant Cells
• Some cells produce a thick secondary wall.
• Adjacent cells are connected by
plasmodesmata extending through both cell
walls.
Review Figures 34.7, 34.8
14
Chapter 34: The Plant Body
figure 34-07.jpg
Figure 34.7
Figure 34.7
Chapter 34: The Plant Body
figure 34-08.jpg
Figure
34.8
Figure 34.8
Chapter 34: The Plant Body
Plant Cells
• Parenchyma cells have thin walls.
• Many store starch or lipids
• Some others carry out photosynthesis.
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Chapter 34: The Plant Body
Plant Cells
• Collenchyma cells provide flexible support.
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Chapter 34: The Plant Body
Plant Cells
• Sclerenchyma cells provide strength and
function when dead.
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Chapter 34: The Plant Body
Plant Cells
• Tracheids and vessel elements are xylem
cells that conduct water and minerals after
the cells die.
Review Figures 34.10
20
Chapter 34: The Plant Body
figure 34-10.jpg
Figure
34.10
Figure 34.10
Chapter 34: The Plant Body
Plant Cells
• Sieve tube members are conducting cells of
the phloem.
• Their activities are often controlled by
companion cells.
Review Figure 34.11
22
Chapter 34: The Plant Body
figure 34-11.jpg
Figure
34.11
Figure 34.11
Chapter 34: The Plant Body
Plant Tissues and Tissue
Systems
• The vascular tissue system conducts water,
minerals, and the products of
photosynthesis.
• The dermal tissue system protects the body
surface.
• The ground tissue system produces and
stores food materials and performs other
functions.
Review Figure 34.12
24
Chapter 34: The Plant Body
figure 34-12.jpg
Figure 34.12
Figure 34.12
Chapter 34: The Plant Body
Forming the Plant Body
• The apical–basal pattern and the radial
pattern are parts of the plant body plan;
• They arise through orderly development.
Review Figure 34.13
26
Chapter 34: The Plant Body
figure 34-13.jpg
Figure
34.13
Figure 34.13
Chapter 34: The Plant Body
Forming the Plant Body
• Plant development differs from animals.
• The plant body is modular, and the growth
of stems and roots is indeterminate.
• Leaves, flowers, and fruits show
determinate growth.
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Chapter 34: The Plant Body
Forming the Plant Body
• Meristems are localized regions of cell
division.
• A hierarchy of meristems generates the
plant body.
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Chapter 34: The Plant Body
Forming the Plant Body
• Apical meristems at the tips of stems and
roots produce the primary growth of those
organs.
Review Figure 34.14
30
Chapter 34: The Plant Body
figure 34-14.jpg
Figure 34.14
Figure 34.14
Chapter 34: The Plant Body
Forming the Plant Body
• Shoot apical and root apical meristems give
rise to primary meristems:
protoderm
 ground
 procambium
Review Figure 34.15

32
Chapter 34: The Plant Body
figure 34-15.jpg
Figure 34.15
Figure 34.15
Chapter 34: The Plant Body
Forming the Plant Body
• In some plants, the products of primary
growth constitute the entire plant body.
Others show secondary growth.
• Two lateral meristems, the vascular
cambium and cork cambium, are
responsible for secondary growth.
Review Figure 34.14
34
Chapter 34: The Plant Body
Forming the Plant Body
• The young root has an apical meristem that gives
rise to the root cap and three primary meristems,
which produce the three tissue systems.
protoderm produces the dermal tissue
system
 ground meristem produces the ground
tissue system
 procambium produces the vascular tissue
system.
Review Figure 34.15

35
Chapter 34: The Plant Body
Forming the Plant Body
• Root tips have three overlapping zones:
the zones of cell division,
 cell elongation, and
 cell differentiation.

Review Figure 34.15
36
Chapter 34: The Plant Body
Forming the Plant Body
• The dermal tissue system consists of the
epidermis, part of which forms root hairs
responsible for absorbing water and
minerals.
Review Figure 34.16
37
Chapter 34: The Plant Body
figure 34-16.jpg
Figure
34.16
Figure 34.16
Chapter 34: The Plant Body
Forming the Plant Body
• The ground tissue system of a young root is
the cortex, whose innermost cell layer, the
endodermis, controls access to the stele.
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Chapter 34: The Plant Body
Forming the Plant Body
• The stele, consisting of pericycle, xylem,
and phloem, is the root’s vascular tissue
system.
• Lateral roots arise in the pericycle.
• Monocot roots have a central pith region.
Review Figure 34.17
40
Chapter 34: The Plant Body
figure 34-17.jpg
Figure
34.17
Figure 34.17
Chapter 34: The Plant Body
Forming the Plant Body
• The shoot apical meristem gives rise to
three primary meristems, with roles similar
to counterparts in the root.
• Leaf primordia on the sides of the apical
meristem develop into leaves.
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Chapter 34: The Plant Body
Forming the Plant Body
• Vascular tissue in young stems is divided
into vascular bundles, each containing
xylem and phloem.
• Pith occupies the center of the monocot
stem.
• Cortex lies to the outside of vascular
bundles in monocot, and pith rays lie
between them.
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Chapter 34: The Plant Body
Forming the Plant Body
• Many eudicot stems and roots show
secondary growth, in which vascular and
cork cambia give rise to secondary xylem
and phloem.
• As secondary growth continues, wood and
bark are produced.
Review Figure 34.19
44
Chapter 34: The Plant Body
figure 34-19a.jpg
Figure 34.19
– Part 1
Figure 34.19 – Part 1
Chapter 34: The Plant Body
figure 34-19b.jpg
Figure 34.19
– Part 2
Figure 34.19 – Part 2
Chapter 34: The Plant Body
Forming the Plant Body
• The vascular cambium lays down layers of
secondary xylem and phloem.
• Living cells within these tissues are
nourished by vascular rays.
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Chapter 34: The Plant Body
Forming the Plant Body
• The periderm consists of cork, cork
cambium, and phelloderm, all pierced at
intervals by lenticels that allow gas
exchange.
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Chapter 34: The Plant Body
Leaf Anatomy Supports
Photosynthesis
• Mesophyll is the photosynthetic tissue of a
leaf.
• Veins bring water and minerals to the
mesophyll and carry products of
photosynthesis to other parts of the plant
body.
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Chapter 34: The Plant Body
Leaf Anatomy Supports
Photosynthesis
• A waxy cuticle prevents water loss from the
leaf, but is impermeable to carbon dioxide.
• Guard cells control opening of stomata, leaf
openings that allow CO2 to enter but also
water to escape.
Review Figure 34.23
50
Chapter 34: The Plant Body
figure 34-23.jpg
Figure 34.23
Figure 34.23