Transcript Slide 1

Roots, Stems, and Leaves
Chapter 23 – Dragonfly
Chapter 35 – Advanced Biology
Biggest Flower
Rafflesia arnoldii The largest flower of any plant in the
world is found on the mottled orange-brown and white
parasitic plant Rafflesia arnoldii. Each bloom is 35.8 in
wide and can weigh up to 24.3 lbs with petals up to
0.75 in think.
You are studying a plant from the arid
southwestern United States. Which of the
following adaptations is least likely to have
evolved in response to water shortages?
a. closing the stomata during the hottest time of
the day
b. development of large leaf surfaces to absorb
water
c. formation of a fibrous root system spread
over a large area
d. mycorrhizae associated with the root system
e. a thick waxy cuticle on the epidermis
A friend has discovered a new plant and
brings it to you to classify. The plant has the
following characteristics: a taproot system
with growth rings evident in cross section
and a layer of bark around the outside.
Which of the following best describes the
new plant?
a. herbaceous eudicot
b. herbaceous monocot
c. woody eudicot
d. woody annual
e. woody monocot
I. Specialized Tissues in Plants
A. Seed Plant Structure
1. Roots
a. Absorb water
b. Absorb minerals
c. Anchor the plant
d. Prevent erosion
e. Protect plant from bacteria and fungi
f. Hold plant upright
2. Stems
a. Carries nutrients
b. Protects against
predators and disease
c. Few mm to 100 m long
d. Must be strong
Tallest Cactus Saguaro (Cereus giganiteus or Carnegiea
gigantea) is the world's tallest cactus. The tallest
specimen on record was found in the Maricopa
Mountains, Arizona, USA in 1988 and had
branches that rose to a record height of 58 ft.
http://ecoworld.com/plants/ecoworld_plants_home.cfm
3. Leaves
a. Main site of photosynthesis
b. Flat for high surface area
c. Protect against water loss
d. Adjustable pores
B. Plant Tissue
Systems
B. Plant Tissue Systems
1. Dermal Tissue
a. “Skin” of the plant
b. Consists of a single layer of epidermal
cells
c. Thick waxy covering
d. Guard cells regulate water loss through
stomata
2. Vascular Tissue
a. “bloodstream”
b. Xylem
1) water-conducting tissue
2) tracheids
a) long, narrow cells with walls that are
impermeable to water
b) have openings that connect cells to
one another
c) not alive
3) vessel elements
a) cells that die, lose their end walls, and
act as pipes transporting water
c. Phloem
1) food-conducting tissue
2) sieve tube members
a) similar to vessel elements, but
the ends look like a sieve
(sieve plate)
3) companion cells
a) surround sieve tube elements
b) support the movement of
substances
d. Vascular cylinder
1) a solid core of xylem and phloem in the
root
e. Vascular bundles
1) Strands of xylem and phloem in the root
3. Ground Tissue
a. All other tissues in plants
b. Parenchyma
1) packed with chloroplasts
2) most photosynthesis occurs here
c. Collenchyma
1) strong, flexible cells
2) provide support for larger plants
d. Sclerenchyma
1) thick, rigid cell walls
2) make cells tough and strong
Root, Stem, and Leaf Tissues
e. Pith
1) ground tissue
that is internal to
vascular tissue
f. Cortex
1) ground tissue
that is external to
vascular tissue
Leaf
Stem
Root
Dermal tissue
Vascular tissue
Ground tissue
4. Plant Growth and Meristematic Tissue
a. Indeterminate vs. Determinate Growth
1) Indeterminate Growth
a) growth that occurs throughout a
plant’s life – never stops
2) Determinate Growth
a) organism ceases to grow when
reaches a certain size
b) most animals and some plant
organs such as leaves
b. Meristem – clusters of tissue that are
responsible for continued plant growth
c. Meristematic tissue is the only plant
tissue that produces new cells by mitosis
d. Unspecialized cells
e. Apical meristerm
1) undifferentiated cells that divide to
increase stem and root length
2) cause the plant to grow in length
(primary growth)
f. Lateral Meristem
1) cause a growth in
thickness
(secondary growth)
2) occurs in stems and roots of woody plants
3) vascular cambium and cork cambium –
adds layers of vascular tissue called
secondary xylem (wood) and secondary
phloem
g. Differentiation – process in which cells
become specialized in structure and
function
Concept Map
Plant Tissues
include
includes
includes
includes
includes
includes
Concept Map
Plant Tissues
include
Dermal
tissue
Meristematic Vascular
tissue
tissue
includes
includes
includes
includes
Ground
tissue
includes
Concept Map
Plant Tissues
include
Dermal
tissue
Meristematic Vascular
tissue
tissue
includes
includes
Epidermal
cells
includes
includes
Ground
tissue
includes
Concept Map
Plant Tissues
include
Dermal
tissue
Meristematic Vascular
tissue
tissue
includes
Epidermal
cells
includes
Xylem
includes
Phloe
m
includes
Ground
tissue
includes
Concept Map
Plant Tissues
include
Dermal
tissue
Meristematic Vascular
tissue
tissue
includes
Epidermal
cells
includes
Xylem
includes
Tracheids
Vessel
elements
Phloe
m
includes
Ground
tissue
includes
Concept Map
Plant Tissues
include
Dermal
tissue
Meristematic Vascular
tissue
tissue
includes
Epidermal
cells
includes
Xylem
includes
Tracheids
Vessel
elements
Ground
tissue
includes
Phloe
m
includes
Sieve tube Companion
cells
members
Concept Map
Plant Tissues
include
Dermal
tissue
Meristematic Vascular
tissue
tissue
includes
Epidermal
cells
includes
Xylem
includes
Tracheids
Vessel
elements
Phloe
m
Ground
tissue
includes
Parenchyma Collenchyma Schlerenchyma
cells
cells
cells
includes
Sieve tube Companion
cells
members
An evolutionary adaptation that
increases exposure of a plant to light in
a dense forest is
a. closing of the stomata.
b. absence of petioles.
c. lateral buds.
d. intercalary meristems.
e. apical dominance.
Which of the following is not a
characteristic of parenchyma cells?
a. thin primary walls
b. lack of secondary walls
c. flexible primary walls
d. little metabolism and synthesis
e. lack of specialization
Which of the following tissues is incorrectly
matched with its characteristics?
a. Collenchyma –
b. Epidermis –
c. Sclerenchyma –
d. meristematic tissue –
e. Parenchyma –
Which of the following tissues is incorrectly
matched with its characteristics?
a. Collenchyma - uniformly thick-walled
supportive tissue
b. Epidermis - protective outer covering of plant
body
c. Sclerenchyma - heavily lignified secondary
walls
d. meristematic tissue - undifferentiated tissue
capable of cell division
e. Parenchyma - thin-walled, loosely packed,
unspecialized cells
The vascular bundle in the shape of a
single central cylinder in a root is
called the
a. cortex.
b. periderm.
c. stele.
d. pith.
e. endodermis.
The photosynthetic cells in the interior of
a leaf are what kind of cells?
a. parenchyma
b. phloem
c. collenchyma
d. endodermis
e. sclerenchyma
II. Roots
** the surface of the roots of a rye plant once
measured 600 square meters
A. Types of Roots
1. Taproot
a. Dicots
b. Long and thick root
2. Fibrous root
a. Monocots
b. Branched extensively
B. Root Structure and Growth
1. Epidermis – outside layer
a. Protection
b. Absorption
c. Covered with root hairs
1) provides a large
surface area
2. Vascular cylinder
a. Central cylinder of vascular tissue
3. Large area of ground tissue between the
epidermis and vascular tissue
a. Cortex
1) spongy layer of ground tissue
b. Endodermis
1) completely encloses the root’s
vascular subsystem
4. Root cap
a. Protects the root as it grows
b. Secretes a slippery substance
C. Root Functions
1. Anchor the plant
2. Uptake of Plant Nutrients
a. Soil
1) Earth’s surface layer that supports
plant life
2) good soil
a) 25% air (CO2 and O2)
b) 25% water
c) 45% minerals
d) 5% organic matter
3) minerals
a) sand - largest
b) silt
c) clay – smallest
4) loam soil - best
a) 30% sand, 40% silt, 30% clay
b. Nutrients needed by plants
1) atmospheric macronutrients
a) C
b) H
c) O
2) Primary Macronutrients
a) N
b) P
c) K
3) Secondary Macronutrients
a) S
b) Ca
c) Mg
4) Micronutrients
a) B
b) Cu
c) Cl
d) Fe
e) Mn
f) Mo
g) Zn
5) Mnemonic
C. B. HOPKiNS CaFÈ Mighty good
Closed Monday Morning See You Zen
Essential Plant Nutrients
Nutrient
Nitrogen
Role in Plant
Proper leaf growth and color;
synthesis of amino acids,
proteins, nucleic acids, and
chlorophyll
Result of Deficiency
Stunted plant growth; pale
yellow leaves
Synthesis of DNA; development
of roots, stems, flowers, and
Phosphorus seeds
Poor flowering; stunted
growth
Synthesis of proteins and carbs;
development of roots, stems, and
Potassium flowers; resistance to cold &
disease
Weak stems and stunted
roots; edges of leaves turn
brown
Magnesium Synthesis of chlorophyll
Thin stems; mottled, pale
leaves
Calcium
Cell growth and division; cell wall Stunted growth; curled
structure; cellular transport;
leaves
enzyme action
3. Active Transport of Minerals
a. Passive transport vs. active transport
b. Active transport proteins use ATP to
pump mineral ions from the soil into the
plant
4. The high concentration of mineral
ions in the plant cells causes water
molecules to move into the plant via
osmosis (passive transport)
a. osmosis – movement of water from
an area of high concentration to an
area of low concentration
5. Osmosis and active transport move water
and nutrients into the Vascular Cylinder
a. The casparian strip allows nutrient ions
and water to move into the vascular
cylinder, but not out – they are trapped
6. Root pressure - Because the nutrient ions
and water molecules are trapped, they can
only go up
The driving force that pushes the root tip
through the soil is due primarily to
a. continuous cell division in the root cap at
the tip of the root.
b. continuous cell division just behind the
root cap in the center of the apical
meristem.
c. elongation of cells behind the root apical
meristem.
d. A and B only.
e. A, B, and C.
Transport in Roots
Questions
Water Absorption
Nutrient Uptake
Transport in Roots
Questions
1. How does
the process
occur?
Water Absorption
Nutrient Uptake
Transport in Roots
Questions
1. How does
the process
occur?
2. List in
order the root
tissues
involved in
this process.
Water Absorption
Nutrient Uptake
III. Stems
A. Stem Structure and Function
1. Functions
a. Produce leaves, branches, and flowers
b. Hold leaves up to the sunlight
c. Transport substances between roots
and leaves
d. Some photosynthesize
e. Some also serve as storage (tuber,
bulb, corm, rhizome
2. Structure
a. Node
1) the point where
leaves attach
b. Internode
1) region between nodes
c. bud
1) contain undeveloped tissue that can
produce new stems and leaves
B. Monocot and Dicot Stems
1. Monocot
a. Vascular bundles (xylem and phloem)
are scattered throughout the stem
2. Dicot
a. In dicots and most gymnosperms
vascular bundles are arranged in a
cylinder
b. Pith
1) the parenchyma cells inside the ring of
vascular tissue
C. Primary Growth of Stems
1. Primary Growth
a. New cells are produced at the tips of
roots and shoots
2. occurs at the tips of
roots and shoots
3. takes place in all
seed plants
D. Secondary Growth of Stems
1. Secondary Growth
a. Stems increasing in width
b. In conifers and dicots, secondary growth
takes place in lateral meristematic tissues
called vascular
cambium and
cork cambium
c. Vascular cambium
1) lateral meristematic tissue produces
vascular tissue increasing stem width
d. Cork cambium
1) produces outer covering of stems
2. Formation of Wood
a. Heartwood
1) older xylem that no longer conducts
water
b. Sapwood
1) surrounds the heartwood, is usually
lighter in color, and still conducts
water
3. Formation of Bark
a. Bark
1) all of the tissues outside the vascular
cambium
2) includes phloem, cork cambium, and
cork
Which of the following is true about
secondary growth in plants?
a. Flowers may have secondary growth.
b. Secondary growth is a common feature of
eudicot leaves.
c. Secondary growth is produced by both the
vascular cambium and the cork cambium.
d. Primary growth and secondary growth
alternate in the life cycle of a plant.
e. Plants with secondary growth are typically
the smallest ones in an ecosystem.
The vascular system of a three-year-old
eudicot stem consists of
a. 3 rings of xylem and 3 of phloem.
b. 2 rings of xylem and 3 of phloem.
c. 2 rings of xylem and 2 of phloem.
d. 3 rings of xylem and 1 of phloem.
e. 2 rings of xylem and 1 of phloem.
IV. Leaves
A. Function
1. carry out photosynthesis
B. Leaf Structure
1. Blade
a. Thin, flattened sections to collect
sunlight
b. Simple or compound (consisting of
many leaflets)
2. Petiole
a. Attaches blade to stem
C. Leaf Functions
1. Photosynthesis
a. Mesophyll
1) this is where photosynthesis occurs
b. Palisade mesophyll
1) closely packed columnar cells that
absorb light
c. Spongy mesophyll
1) loose tissue with many air spaces
connected to stomata
d. Stomata
1) porelike openings in the underside of
the leaf that allow CO2 and O2 to
diffuse in and out of the leaf
e. Guard cells
1) control the opening and closing of the
stomata
2. Transpiration
a. The loss of water through leaves
3. Gas Exchange
a. Plants keep their stomata open just
enough to allow photosynthesis to take place
but not so much that they lose an excessive
amount of water
b. High water pressure causes the guard
cells to open the stomata
c. Guard cells work to maintain
homeostasis
Which of the following is incorrectly paired
with its structure and function?
a. Sclerenchyma b. Periderm c. Pericycle d. Mesophyll e. ground meristem -
Which of the following is incorrectly paired
with its structure and function?
a. Sclerenchyma - supporting cells with thick
secondary walls
b. Periderm - protective coat of woody stems
and roots
c. Pericycle - waterproof ring of cells
surrounding the central stele in roots
d. Mesophyll - parenchyma cells functioning
in photosynthesis in leaves
e. ground meristem - primary meristem that
produces the ground tissue system
All of the following cell types are
correctly matched with their functions
except
a. mesophyll-photosynthesis
b. guard cell-regulation of transpiration
c. sieve-tube member-translocation
d. vessel element-water transport
e. companion cell-formation of
secondary xylem and phloem
V. Transport in Plants
A. Water Transport
1. root pressure, capillary action, and
transpiration provide enough force to move
water through the xylem up any plant
2. Capillary Action
a. Cohesion
1) molecular attraction of like substances
b. Adhesion
1) molecular attraction of unlike
substances
c. Capillary action
1) the upward movement of a fluid
against the force of gravity
2) due to cohesion and adhesion
3. transpiration
a. As water is lost through stomata, osmotic
pressure moves water out of the vascular
tissue
Evaporation of water
molecules out of leaves.
Pull of water molecules
upward from the roots.
B. Nutrient Transport
1. nutrients are pushed through phloem
2. Source to Sink
a. Pressure-Flow hypothesis
- “When nutrients are pumped into or
removed from the phloem system, the
change in concentration causes a movement
of fluid in that same direction. As a result,
phloem is able to move nutrients in either
direction to meet the nutritional needs of
the plant.”
Phloem
Transport
Phloem
Sugar
molecules
Source cell
Movement
of water
Movement
of sugar
Sink cell
Xylem

The End
Phloem
Transport
Phloem
Sugar
molecules
Source cell
Movement
of water
Movement
of sugar
Sink cell
Xylem

THE END