Name _______________________________________
Plant Structure and Function Notes Outline
Period ______
Tissues
 A plant’s body is made of _____________
that form _____________.
 In ________________ plants, there are
________ types of _________ systems.
 _______________ Tissue System
 Forms the protective ___________ layer of a plant.
 ________________ Tissue System
 Makes up much of the _________ of the nonwoody parts of a plant,
including _________, __________, and ___________.
 ________________ Tissue System
 Forms strands that conduct _________, ____________ and
_______________ compounds throughout a __________ plant.
Dermal Tissue System
 ____________ tissue covers the
______________ of a plant’s body.
 In the _________________ parts of a
plant, dermal tissue forms a “________”
called the _____________________.
 The __________________ of most plants is made up of a _____________ layer
of flat __________.
 A waxy __________, which prevents ___________ loss, __________ the
epidermis of the __________ and _____________.
 Often the ________ of the _______________ have ________-like extensions or
other ___________________.
 _________________ of the _______________ cells on __________ and
_____________ often help to ________ water _______.
 ________________ of the epidermal _______ on ________ tips help
________________ water ________________.
 The ____________ tissue on woody ________ and ____________ consists of
several layers of ____________ cells that are referred to as ____________.
 ____________ cells contain a ___________________ chemical and are
_____ covered by a waxy _____________.
 In addition to ________________, _____________ tissue also functions in
________ exchange and in the ______________ of mineral ________________.
Ground Tissue System
 _______________ tissue makes up much of the ____________ of most plants.
 Most __________ tissue consists of ______-walled ________ that remain
__________ and keep their ____________ after they ______________.
 Some ______________ tissue contains some __________-walled cells.
 ____________ tissue has different ______________, depending on where it is
_________________ in a plant.
 The ground tissue in _____________, which is packed with ________________,
is specialized for _________________________.
 The ground tissue in __________ and _________ functions mainly in the
____________ of ________, __________, and _________.
 Throughout the _________ of a plant, __________ tissue also _____________
and _________________ the third kind of plant tissue – ______________ tissue.
Vascular Tissue System
 Plants have _______ kinds of _________________ tissue.
 _____________ and ______________.
 Both _____________ and _______________ contain strands of ________ that
are _____________ end to end and act like tiny __________.
 These _______________ of cells act as a ______________ system, carrying
______________ and dissolved _________________ throughout a plant’s body.
Xylem
 ___________ has ________-walled ________ that conduct _________ and
_______________ nutrients from a plant’s ____________ through its _________
to its _____________.
 The conducting cells in ___________ must ________ their cell _____________,
_______________, and _________________ before they can conduct _______.
 At ____________, all that is left of these ______ is their cell ____________.
 One type of __________ cell found in all vascular plants is called a __________.
 ______________ are ____________, elongated, and ___________ at each end.
 ___________ flows from one ____________ to the next through _______, which
are _____ areas in the cell _________.
 Gnetophytes and flowering plants also have a second type of __________ cell,
which makes up ______________ strands called _____________.
 The _______________ cells are _________ than _______________ and have
large ______________________ in their ends.
 The _____________________ allow ____________ to flow more _________
between _______________ cells.
Phloem
 _______________ contains cells that conduct ___________ and other
______________ throughout a plant’s body.
 The conducting _____________ of phloem have a cell _________, a cell
________________, and _____________________.
 These _________ either _________ organelles or have _______________
organelles.
 The __________________ strands in _____________ are called __________
____________.
 _________ in the walls ______________ neighboring ________-tube cells
connect the _________________ and allow _____________ to pass freely from
________ to __________.
 Beside the _________ tubes are rows of ______________________ cells, which
contain _________________.
 _________________ cells carry out cellular _____________, protein
______________, and other _____________ functions for the ______-tube cells.
Plant Cells and Tissues
Plant Tissue
_____________
Tissue
_____________
Tissue
_____________
Tissue
Cell Types
Roots
 Most ___________ are ________________ to
the spot where they _________ by _________,
which also ___________ water and mineral
_________________.
 In many plants, _________ also function in the
______________ of organic nutrients, such as
________ and ____________.
 Many _________, such as ___________ and
___________, have a large ___________ root from which much ___________
roots _________.
 This type of ________ system is called a ________________ system.
 Most ____________ such as ___________, have a highly ____________,
_____________ root system.
 Some plants have _________ that grow from ____________________ stems or
______________.
 These roots are called _____________________ roots.
 The _________ roots of corn and the ________ roots of orchids are
examples of ____________________ roots.
 A _________ has a central _________ of ___________________ tissue that is
surrounded by ______________ tissue.
 The _____________ tissue surrounding the ____________ tissue is called the
__________.
 Roots are covered by __________ tissue.
 An ________________ covers all of a
_________ except for the root ______.
 The _____________ cells just behind a
root _______ often produce root
_________, which are slender
_______________ of the cell __________________.
 Root ___________ greatly increase the surface ___________ of a root and its
___________ to absorb __________ and mineral _______________.
 A mass of ________ called the root ______ covers and ____________ the
actively ________________ root tip.
 A layer of ________ replaces the ______________ in the _________ sections of
a root.
 Many plants have __________ that become __________ as they get ________.
 Layers of ___________ replace the ___________ tissue in ___________ roots.
Stems
 The ______________ of most plants consist of ___________ and
______________.
 _____________ support the __________ and house the _________________
tissue, which ________________ substances between the _________ and the
____________.
 Many plants have __________ that are __________________ for other
________________.
 Stems of _______________ store _________.
 _____________ are stems that are specialized for _____________ storage
and for __________________
reproduction.
 _______________ are attached to a
_________ at points called ___________.
 The space between two ____________ is
called an ____________________.
 _____________ that can ________ into new
_____________ are also located at the
____________ on a _________.
 Other features of a __________ depend on
whether the stem is __________ or
___________________.
Nonwoody Stems
 A plant with _____________ that are _____________ and usually ___________
is called an ___________________ plant.
 _______________ plants include ____________, clovers, and _________.
 The __________ of herbaceous plants contain bundles of __________ and
_________________ called vascular ________________.
 __________________ stems are covered by an _________________.
 ______________ in the ____________ enable the _________ to exchange
_________ with the _________________ air.
 The _________________ bundles are surrounded by _____________ tissue.
 In ____________ stems, such as that of __________, the vascular bundles
are _________________ in the _______________ tissue.
 In ___________ stems, the vascular bundles are arranged in a _________.
 The ______________ tissue outside the _________ of vascular
bundles is called the ______________.
 The ground tissue __________ the ______ is called the ________.
Woody Stems
 __________ and __________, such as pines, oaks, roses, and hollies have
____________ stems.

________________
stems are ________ and __________________.
 _________, which produce ______ growth, are found at the _______ and at the
__________.
 They exchange ___________ through __________ in their _________.
 A _____________ woody stem has a central _________ of _______ and a
__________ of vascular __________, which ________ into solid ____________
as the stem ________________.
 Layers of ______________ form the innermost _____________ and are the
__________ component of ___________.
 A cylinder of ___________ lies outside the cylinder of ___________.
 _____________ stems are covered by ____________, which _____________
them from physical _____________ and helps ____________ water _______.
 Together, the layers of _________ and ___________ make up the _______ of a
____________ stem.
 A ____________ woody stem contains many __________ of _________ and is
______________ by a thick layer of _______________________.
 The ____________ in
_____________________, which
can no longer _______________
water, provides
________________.
 ________________, which lies
_____________ the
_______________, contains
____________ cells that can ______________ water.
Leaves
 ________________ are the primary
____________________ organs of plants.
 Most __________ have a flattened portion,
called the __________, that is often
________________ to a __________ by a
_________ called the _____________.
 A leaf __________ may be divided into _______ or more ___________ called
______________.
 _____________ with an ________________ blade are called _____________
leaves.
 Leaves with ________ or more ___________ are called _______________
leaves.
 ______________ reduce the ______________ area of a leaf ___________.
 Many plants have highly _______________ leaves that are _______________
for particular ________________.
 The ___________ of a __________ and the __________ of a garden
__________ are ______________ leaves.
 Cactus ___________ are specialized for ____________ and __________
conservation, while garden-pea _________ are specialized for _________.
 A _______ is a mass of _____________ tissue and _____________ tissue
covered by ______________.
 A _____________ coats the ___________ and __________ epidermis.
 Both _____________ and ____________ are found in the __________ of a leaf.
 ____________ are _________________ of vascular ______________ that run
from the tips of ___________ to the edges of _____________.
 In _____________, the ground tissue is called ______________________.
 _______________ cells are packed with _________________, where
___________________________ occurs.
 The ___________________ in ________________ makes leaves look _______.
Structure of a Leaf
Leaves
 Most ________ have leaves with _____ layers of _______________.
 One or more ______ of closely packed _______________ cells make up the
______________ layer, which lies just _________ the upper _______________.
 A layer of _________ packed, ___________ cells, called the _________ layer,
lies ______________ the ____________ layer and the lower ______________.
 The ___________ layer has many ______ spaces through which _________ can
travel.
 ____________, the tiny _________ in the _____________, connect the ______
spaces to the ___________ air.
Movement of Water in Plants
 _________ and __________ nutrients move up from a plant’s _________ to its
____________ through ____________.
 __________ is pulled ______ through a plant as it ______________ from the
plants ____________.
 The __________ of ____________ are coved with many tiny __________, the
____________.
 When the __________ are ________, water _______ diffuses ______ of a leaf.
 This ______ of water ________ from a plant is called __________________.
 In most _____________, more than _____% of the ________ taken in by the
___________ is ultimately ________ through _________________.
 The ____________ contains a _____________ of water that extends from the
__________ to the ___________.
 The _______________ of water _____________ causes water molecules that
are being _________ by a plant to _______ on the water _____________ still in
the __________.
 This _______ extends through the ___________ in the ____________.
 _________ is drawn ____________ in the same way __________ is drawn
through a ______________.
 As long as the _____________ of water in the __________ does not _________,
__________ will keep moving ___________ as ___________________ occurs.
 _____________ take in ___________ from the _________ by ______________.
 This _____________ enters the ___________ and _____________ the water
____________ through ___________________.
Guard Cells and Transpiration
 A _________ is surrounded by a ________ of ___________ cells that are
__________ like two cupped hands.
 ____________ in water ___________ within the __________ cells cause the
__________ to _________ or __________.
 When the __________ cells take in __________, they ___________.
 Extra _____________ strands in their cell _________ permit the ________
to ______________ in length but not in _____________.
 As a result, ___________ cells that take in ____________ bend _________ from
each other, _____________ the __________ and
allowing _______________ to proceed.
 When ___________ leaves the ___________ cells, they ____________ and
move ___________ to each other, ____________ the
stoma and ______________ transpiration.
 The _______ of water from ___________ cells (for
any reason) causes ________________ to _________, _______________
further water ________.
 This is an example of ________________________.
Movement of Organic Compounds in Plants
 _______________ compounds move throughout a plant within the _________.
 ____________ use the term __________ to refer to a part of a plant that
_____________ organic compounds for _______ parts of the ________.
 A _________ is a __________ because it makes __________ during
____________________.
 A ________ that stores _________ is also a ___________.
 ___________ use the term __________ to refer to a part of a _________ that
organic compounds are ________________ to.
 ____________ growing _________, such as root ______ and developing
_________, are examples of ________.
 The _____________ of organic compounds ____________ a plant from a
__________ to a _________ is called ____________________.
Translocation
 The ________________ of organic _______________ in a plant is more
__________ than the movement of ___________ for three reasons.
1. _________ flows ___________ through empty ___________ cells, but
______________ compounds must ______ through the
_________________ of ___________ phloem _________.
2. ____________ only moves _____ in _______, while _____________
compounds move in ____ directions in __________.
3. __________ can ___________ through cell ________________ but
____________ compounds _____________.
 The ______________ botanist Ernst ___________ proposed a model of
___________________ in _________. In this _____________ –_______
________________:
 ___________ from a __________ enters _____________ cells by
______________ __________________.
 When the ___________ concentration in the phloem _________________,
____________ enters the __________ tubes in ___________ from
___________ by ______________.
 _______________ builds up ___________ the __________-tube
________ and ____________ sugar through the ___________ tubes.
 __________ moves from _____________ cells into a _________ by
_______________ ____________________.
Plant Structure and Function Notes Outline –Answer Key (guide)
Tissues


A plant’s body is made of tissues that form organs.
In vascular plants, there are three types of tissue systems.
 Dermal Tissue System
 Forms the protective outer layer of a plant.
 Ground Tissue System
 Makes up much of the inside of the nonwoody parts of a plant, including roots,
stems, and leaves.
 Vascular Tissue System
 Forms strands that conduct water, minerals and organic compounds throughout
a vascular plant.
Dermal Tissue System







Dermal tissue covers the outside of a plant’s body.
In the nonwoody parts of a plant, dermal tissue forms a “skin” called the epidermis.
The epidermis of most plants is made up of a single layer of flat cells.
A waxy cuticle, which prevents water loss, coats the epidermis of the stems and leaves.
Often the cells of the epidermis have hair-like extensions or other structures.
 Extensions of the epidermal cells on leaves and stems often help to slow water loss.
 Extensions of the epidermal cells on root tips help increase water absorption.
The dermal tissue on woody stems and roots consists of several layers of dead cells that are
referred to as cork.
 Cork cells contain a waterproof chemical and are not covered by a waxy cuticle.
In addition to protection, dermal tissue also functions in gas exchange and in the absorption of
mineral nutrients.
Ground Tissue System







Ground tissue makes up much of the inside of most plants.
Most ground tissue consists of thin-walled cells that remain alive and keep their nucleus after
they mature.
Some ground tissue contains some thick-walled cells.
Ground tissue has different function, depending on where it is located in a plant.
The ground tissue in leaves, which is packed with chloroplasts, is specialized for
photosynthesis.
The ground tissue in stems and roots functions mainly in the storage of water, sugar, and
starch.
Throughout the body of a plant, ground tissue also surrounds and supports the third kind of
plant tissue – vascular tissue.
Vascular Tissue System



Plants have two kinds of vascular tissue.
 xylem and phloem.
Both xylem and phloem contain strands of cells that are stacked end to end and act like tiny
pipes.
These strands of cells act as a plumbing system, carrying fluids and dissolved
substances throughout a plant’s body.
Xylem









Xylem has thick-walled cells that conduct water and mineral nutrients from a plant’s roots
through its stems to its leaves.
The conducting cells in xylem must lose their cell membrane, nucleus, and cytoplasm before
they can conduct water.
At maturity, all that is left of these cells is their cell walls.
One type of xylem cell found in all vascular plants is called a tracheid.
Tracheids are narrow, elongated, and tapered at each end.
Water flows from one tracheid to the next through pits, which are thin areas in the cell walls.
Gnetophytes and flowering plants also have a second type of xylem cell, which makes up
conducting strands called vessels.
The vessel cells are wider than tracheids and have large perforations in their ends.
The perforations allow water to flow more quickly between vessel cells.
Phloem







Phloem contains cells that conduct sugars and other nutrients throughout a plant’s body.
The conducting cells of phloem have a cell wall, a cell membrane, and cytoplasm.
These cells either lack organelles or have modified organelles.
The conducting strands in phloem are called sieve tubes.
Pores in the walls between neighboring sieve-tube cells connect the cytoplasms and allow
substances to pass freely from cell to cell.
Beside the sieve tubes are rows of companion cells, which contain organelles.
Companion cells carry out cellular respiration, protein synthesis, and other metabolic functions
for the sieve-tube cells.
Plant Cells and Tissues
Plant Tissue
Cell Types
Dermal Tissue
Epidermal cells, Guard cells, Cork cells
Ground Tissue
Mesophyll cells, Cortex cells, pith cells
Vascular Tissue
Vessel cells, Tracheids, Sieve-tube cells, Companion cells
Roots










Most plants are anchored to the spot where they grow by roots, which also absorb water and
mineral nutrients.
In many plants, roots also function in the storage of organic nutrients, such as sugar and
starch.
Many dicots, such as carrots and radishes, have a large central root from which much smaller
roots branch.
This type of root system is called a taproot system.
Most monocots such as grasses, have a highly branched, fibrous root system.
Some plants have roots that grow from aboveground stems or leaves.
 These roots are called adventitious roots.
 The prop roots of corn and the aerial roots of orchids are examples of adventitious
roots.
A root has a central core of vascular tissue that is surrounded by ground tissue.
The ground tissue surrounding the vascular tissue is called the cortex.
Roots are covered by dermal tissue.
An epidermis covers all of a root except for the root tip.






The epidermal cells just behind a root tip often produce root hairs, which are slender
projections of the cell membrane.
Root hairs greatly increase the surface area of a root and its ability to absorb water and
mineral nutrients.
A mass of cells called the root cap covers and protects the actively growing root tip.
A layer of cork replaces the epidermis in the older sections of a root.
Many plants have roots that become woody as they get older.
Layers of xylem replace the ground tissue in woody roots.
Stems







The shoots of most plants consist of stems and leaves.
Stems support the leaves and house the vascular tissue, which transports substances
between the roots and the leaves.
Many plants have stems that are specialized for other functions.
 Stems of cactuses store water.
 Potatoes are stems that are specialized for nutrient storage and for asexual
reproduction.
Leaves are attached to a stem at points called nodes.
The space between two nodes is called an internode.
Buds that can grow into new branches are also located at the nodes on a stem.
Other features of a stem depend on whether the stem is woody or nonwoody.
Nonwoody Stems





A plant with stems that are flexible and usually green is called an herbaceous plant.
 Herbaceous plants include violets, clovers, and grasses.
The stems of herbaceous plants contain bundles of xylem and phloem called vascular
bundles.
Herbaceous stems are covered by an epidermis.
Stomata in the epidermis enable the stems to exchange gases with the outside air.
The vascular bundles are surrounded by ground tissue.
 In monocot stems, such as that of corn, the vascular bundles are scattered in the
ground tissue.
 In dicot stems, the vascular bundles are arranged in a ring.
 The ground tissue outside the ring of vascular bundles is called the cortex.
 The ground tissue inside the ring is called the pith.
Woody Stems











Trees and shrubs, such as pines, oaks, roses, and hollies have woody stems.
Woody stems are stiff and nongreen.
Buds, which produce new growth, are found at the tips and at the nodes.
They exchange gasses through pores in their bark.
A young woody stem has a central core of pith and a ring of vascular bundles, which fuse
into solid cylinders as the stem matures.
Layers of xylem form the innermost cylinder and are the major component of wood.
A cylinder of phloem lies outside the cylinder of xylem.
Woody stems are covered by cork, which protects them from physical damage and helps
prevent water loss.
Together, the layers of cork and phloem make up the bark of a woody stem.
A mature woody stem contains many layers of wood and is covered by a thick layer of
heartwood.
The xylem in heartwood, which can no longer conduct water, provides support.

Sapwood, which lies outside the heartwood, contains vessel cells that can conduct water.
Leaves














Leaves are the primary photosynthetic organs of plants.
Most leaves have a flattened portion, called the blade, that is often attached to a stem by a
stalk called the petiole.
A leaf blade may be divided into two or more sections called leaflets.
Leaves with an undivided blade are called simple leaves.
Leaves with two or more leaflets are called compound leaves.
Leaflets reduce the surface area of a leaf blade.
Many plants have highly modified leaves that are specialized for particular purposes.
 The spines of a cactus and the tendrils of a garden pea are modified leaves.
 Cactus spines are specialized for protection and water conservation, while garden-pea
tendrils are specialized for climbing.
A leaf is a mass of ground tissue and vascular tissue covered by epidermis.
A cuticle coats the upper and lower epidermis.
Both xylem and phloem are found in the veins of a leaf.
Veins are extensions of vascular bundles that run from the tips of roots to the edges of leaves.
In leaves, the ground tissue is called mesophyll.
Mesophyll cells are packed with chloroplasts, where photosynthesis occurs.
The chlorophyll in chloroplasts makes leaves look green.
Leaves





Most plants have leaves with two layers of mesophyll.
One or more rows of closely packed columnar cells make up the palisade layer, which lies just
beneath the upper epidermis.
A layer of loosely packed, spherical cells, called the spongy layer, lies between the palisade
layer and the lower epidermis.
The spongy layer has many air spaces through which gases can travel.
Stomata, the tiny holes in the epidermis, connect the air spaces to the outside air.
Movement of Water in Plants













Water and mineral nutrients move up from a plant’s roots to its leaves through xylem.
Water is pulled up through a plant as it evaporates from the plants leaves.
The surface of leaves are coved with many tiny pores, the stomata.
When the stomata are open, water vapor diffuses out of a leaf.
This loss of water vapor from a plant is called transpiration.
In most plants, more than 90% of the water taken in by the roots is ultimately lost through
transpiration.
The xylem contains a column of water that extends from the leaves to the roots.
The cohesion of water molecules causes water molecules that are being lost by a plant to pull
on the water molecules still in the xylem.
This pull extends through the water in the xylem.
Water is drawn upward in the same way liquid is drawn through a siphon.
As long as the column of water in the xylem does not break, water will keep moving upward as
transpiration occurs.
Roots take in water from the soil by osmosis.
This water enters the xylem and replaces the water lost through transpiration.
Guard Cells and Transpiration






A stoma is surrounded by a pair of guard cells that are shaped like two cupped hands.
Changes in water pressure within the guard cells cause the stoma to open or close.
When the guard cells take in water, they swell.
 Extra cellulose strands in their cell walls permit the cells to increase in length but not in
diameter.
As a result, guard cells that take in water bend away from each other, opening the stoma and
allowing transpiration to proceed.
When water leaves the guard cells, they shorten and move closer to each other, closing the
stoma and stopping transpiration.
The loss of water from guard cells (for any reason) causes stomata to close, stopping further
water loss.
 This is an example of homeostasis.
Movement of Organic Compounds in Plants




Organic compounds move throughout a plant within the phloem.
Botanists use the term source to refer to a part of a plant that provides organic compounds for
other parts of the plant.
 A leaf is a source because it makes starch during photosynthesis.
 A root that stores sugar is also a source.
Botanists use the term sink to refer to a part of a plant that organic compounds are delivered
to.
 Actively growing parts, such as root tips and developing fruits, are examples of sinks.
The movement of organic compounds within a plant from a source to a sink is called
translocation.
Translocation


The movement of organic compounds in a plant is more complex than the movement of water
for three reasons.
 Water flows freely through empty xylem cells, but organic compounds must pass
through the cytoplasm of living phloem cells.
 Water only moves up in xylem, while organic compounds move in all directions in
phloem.
 Water can diffuse through cell membranes but organic compounds cannot.
The German botanist Ernst Munch proposed a model of translocation in 1924. In this
pressure –flow model:
 Sugar from a source enters phloem cells by active transport.
 When the sugar concentration in the phloem increases, water enters the sieve tubes in
phloem from xylem by osmosis.
 Pressure builds up inside the sieve-tube cells and pushes sugar through the sieve
tubes.
 Sugar moves from phloem cells into a sink by active transport.