Download PLANT TISSUES 12 MARCH 2014 Lesson

PLANT TISSUES
Lesson Description
In this lesson we:
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Identify the different types of plant tissue
Be able to relate the different structures with the different functions
Summary
Plant Tissue
12 MARCH 2014
TISSUE
Meristematic
Epidermis
LOCATION
 Apical – tips of roots
and shoots
 Lateral – sides of
roots and stems
 Vascular cambium –
between xylem and
phloem of dicots
 Cork cambium –
inside cork cells
Outer covering of roots,
stems and leaves
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Forms bulk of roots,
stems, leaves and
flowers.
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Chlorenchyma
 In upper layers of
leaves and stems
 Palisade and spongy
mesophyll of leaves
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Collenchyma
 In epidermis of young
stems
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Parenchyma
STRUCTURE
Thin willed
Large nucleus
No intercellular
spaces
Regular shape
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Stems and leaves
 Guard cells
surrounding a
stoma
 Regular shape
 Thin walled
 No chloroplasts
 No air spaces
 Covered with a
cuticle
Roots
 Regular shape
 No cuticle
 Outgrows – root
hairs
Irregularly shaped
round, oval
Thin-walled, large
vacuole
Large intercellular
spaces
Lack chloroplasts
Parenchyma tissue
with chloroplasts
Thin-walled,
irregularly shaped
with intercellular
spaces.
Elongated upper layer
– palisade layer
Regular shape
No intercellular
spaces
Corners of cells are
thickened
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FUNCTION
Actively dividing –
Mitosis
Produce new cells for
 Growth in length
and width
 Replace worn-out
or damaged
tissue
Differentiate into
different types of
tissue
Protect deeper-lying
tissue
Cuticle reduced loss
of water vapour by
transpiration
Guard cells control
opening and closing
of stoma, control loss
of water vapour and
gas exchange.
In roots help to
absorb water from
soil.
Packing tissue
Stores food as starch
or sugars
Intercellular airspaces allow water
and gases to pass
through.
Manufactures food y
photosynthesis.
Give support and
strength to aboveground parts
Sclerenchyma
Xylem
 Fibres
 In epidermis or
stems
 Cap around
vascular bundles
of dicot stems
 Sheath
completely
around vascular
bundle of
monocots
 Stone cells in shells of
nuts and hard parts of
fruits
Within veins of leaves,
vascular bundles of
stems and stele of roots
 Fibres
 Long with
tapered ends
 Thick- walled
 Very small inner
cavities
 Stone cells
 Small, oval,
irregular cells
 Extremely thick
walls with lumens
almost completely
blocked.
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Give mechanical
support to plant.
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Vessels and
tracheids transport
water and mineral
salts from roots to
stems and leaves
Give strength and
support
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Phloem
Within veins of leaves,
vascular bundles of
stems and stele of roots
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Vessels
 Cylindrical cells
 Cross walls
perforated or
absent
 No cell contents –
dead cells
 Form continuous
tubes from roots
to leaves
 Thick walls
(lignin)
 Lignin laid down
to form patterns
Tracheids
 Ends tapered
 Have perforated
cross walls
Fibres and
parenchyma as
described above.
Sieve tubes
 Cylindrical cells
 Cross walls
perforated to form
sieve plates
 Thin-walled cells
 Contain strands
of cytoplasm
continuous with
that of next cell
 Living cells
Companion cells
 Lie next to sieve
tubes
 Thin walled with
well defined
nucleus
 Cross wall
present
Fibres and
parenchyma as
described above.
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Sieve tubes transport
manufactures food
from leaves to all
parts of body
Companion cells
probably control the
activities of sieve
tubes.
Diagrams
Parenchyma
Epidermal
Epidermal Tissue – Root Hair
Epidermal Tissue – Stomata
Collenchyma
Sclerenchyma
Xylem
Phloem
Test Yourself
Question 1
The chief food making tissue of a plant is called
A
Chlorenchyma
B
Cortex
C
Phloem
D
Epidermis
E
Xylem
Question 2
In a stem, collenchyma cells are mainly found near the
A
xylem tissue
B
epidermal tissue
C
phloem tissue
D
chlorenchyma tissue
E
pith
Question 3
Tracheids differ from vessels because they are
A
in the phloem
B
much smaller
C
thickened with lignin
D
only found in softwood trees
E
also found in sclerenchyma
Question 4
An example of a cell thickened with extra cellulose is
A
collenchyma
B
parenchyma
C
tracheids
D
vessels
E
sclerenchyma
Question 5
Root hair cells are …..
A
not living because the wall is lignified
B
concerned with the entry of gases into the plant
C
able to open and close due to uneven thickening
D
waterproof to stop water diffusing into the soil
E
concerned with absorbing water and mineral salts for the plant.
Question 6
Most of the photosynthesis in a plant occurs in the
A
spongy mesophyll
B
guard cells of the stoma
C
green cortex cells
D
phloem of the leaf vein
E
palisade mesophyll
Question 7
Which of the following is NOT found in phloem tissue?
A
parenchyma
B
collenchyma
C
sieve tubes
D
companion cells
E
fibres
Question 8
Which of the following is not a feature of sclerenchyma?
A
contains fibres
B
may contain stone cells
C
lignified walls
D
living tissue
E
used for support
Question 9
Phloem tissue is...
A
found in vascular bundles.
B
made up entirely of non-living cells.
C
a tissue which only conducts nutrients by diffusion.
D
found in leaves only.
Question 10
The cells shown in the diagram on the right can be found in
A
Bananas and pears
B
pears and apples
C
Apples and guavas
D
Guavas and pears.
Improve your Skills
Question 1
Study the diagram below and answer the questions which follow on Plant Tissues.
1.1.
1.2.
1.3.
Name the plant tissues represented by letters A, B, C and D.
Explain how plant tissue labeled B is structurally suited for its function.
Draw a simple diagram to show what the upper epidermis of a leaf would look
like. No labels required.
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Question 2
The photographs/diagrams below show various conducting cells / tissues of a plant.
2.1
Which photograph/diagram (A to D) represents a xylem tracheid?
Give a reason for your answer.
2.2
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Two cells are shown in diagram B.
Which labeled cell in diagram A is a cross section of one of these cells?
(1)
2.3
Give the main function of cell type 4 in diagram D, and state how you were
able to identify the cell.
Of what substance is the cell wall of:
a.) cell 1, and that of
b.) cell 3 made.?
2.4
Links
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Bozeman summary - https://www.youtube.com/watch?v=zHp_voyo7MY
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