Plant Tissues and the Multicellular Plant Body Flashcards
this system is generally underground
root system
aerial portion
shoot system
consists of a vertical stem bearing leaves
and, in flowering plants, flowers and fruits that contain seeds.
shoot system
branch extensively through the soil, forming a network that anchors the plant firmly in place and absorbs water and dissolved minerals from the soil.
Roots
the flattened organs for photosynthesis
Leaves
are attached regularly on the stem, where they absorb the sunlight and atmospheric CO2 used in photosynthesis to produce carbohydrates.
Leaves
Plants are either
herbaceous or woody
theydo not develop persistent woody parts above ground.
Herbaceous plants
develop persistent woody parts
above ground.
Woody plants
what kind of plants are trees and shrubs
Woody plants
example of aerial part of plants
(stems and leaves)
during what climate does the aerial parts of herbaceous plants die back to the ground at the end of
the growing season.
temperate climates
during temperate climates the aerial stemsof woody plants, do they persist or die?
persist
plants (such as corn, geranium, and marigold) that
grow, reproduce, and die in 1 year or season.
Annuals
herbaceous plants examples
corn, geranium, and marigold
Annual plants example
carrot, cabbage, and Queen
Anne’s lace
these plants take 2 years to complete their life cycles
Biennials
these plants are woody or herbaceous plants that live for more than 2 years.
Perennials
All woody plants are
perennials
is the basic structural and functional unit of plants.
cell
is a group of cells that forms a structural and functional unit
tissue
2 classification of tissues
simple tissues
complex tissues
are composed of only one kind of cell
simple tissues
have two or more kinds of cells.
complex tissues
what plant has tissues are organized into three tissue systems,
vascular plants
3 types of tissue system
Ground tissue system
vascular tissue system
dermal tissue system
has a variety of functions, including photosynthesis, storage, and support.
Ground tissue system
an intricate plumbing system that extends
throughout the plant body, conducts various substances, including water, dissolved minerals, and food (dissolved sugar).
vascular tissue system
covers the plant body
dermal tissue system
Roots, stems, leaves, flower parts, and fruits are referred to as
organs
it is when a part composes of all three tissue systems
organs
they form an interconnected
network throughout the plant.
tissue systems
three tissues of herbaceous plants:
Parenchyma,
Collenchyma, and
Sclerenchyma.
growing cell secretes a thin
primary cell wall,
it stretches and
expands as the cell increases in size.
primary cell wall
After the cell stops growing, it sometimes secretes a thick, strong —-
secondary cell wall
it is deposited inside the primary cell wall—that
is, between the primary cell wall and the plasma membrane.
secondary cell wall
a simple tissue composed of parenchyma cells
Parenchyma tissue
is found throughout the plant body and is the most common type of cell and tissue.
parenchyma
functions in photosynthesis contain chloroplasts, whereas
non-photosynthetic parenchyma cells lack chloroplasts.
Parenchyma cells
have the ability to differentiate into other kinds of cells,
particularly when a plant is injured.
Parenchyma cells
(water-conducting cells)
xylem
if xylem is severed, these cells may divide and differentiate into new xylem cells within a few days.
Parenchyma cells
have unevenly thickened primary cell walls
Collenchyma cells
a simple tissue composed of collenchyma cells
Collenchyma tissue
is a flexible tissue that provides much of the support in soft, non woody plant organs.
Collenchyma tissue
are usually elongated
Collenchyma cells
Their primary cell walls are unevenly thickened and are especially thick in the corners.
Collenchyma cells
is not found uniformly throughout the plant and often occurs as
long strands near stem surfaces and along leaf veins.
Collenchyma
The “strings” in a celery stalk (petiole), for example, consist of
collenchyma
both primary cell walls and thick secondary cell walls
Sclerenchyma cells
the secondary cell walls of —– become strong and hard due
to extreme thickening.
sclerenchyma cells
these cells are often dead.
sclerenchyma cells
when do sclerenchyma cells often die
at functional maturity
may occur in several areas of the plant body.
Sclerenchyma tissue
2 types of Sclerenchyma cells
Sclereids
Fibers
short cells that are variable in shape
Sclereids
are common in the shells of nuts and the stones of fruits, such as cherries and peaches
Sclereids
long, tapered cells that often occur in groups or clumps,
are particularly abundant in the wood, inner bark, and leaf ribs (veins) of flowering plants.
Fibers
which is embedded in the ground tissue, transports
needed materials throughout the plant via two complex tissues
vascular tissue system
two complex tissues in the vascular tissue system:
xylem and phloem
conducts water and dissolved minerals from the roots to the stems and leaves and provides structural support.
Xylem
is a complex tissue composed of four different cell types
xylem
four different cell types:
tracheids, vessel elements, parenchyma cells, and fibers.
these 2 elements—actually conduct water and dissolved
minerals.
tracheids and vessel elements
they ccontain parenchyma cells
Xylem
Xylem contains parenchyma cells, known as
xylem parenchyma
perform
storage functions, and xylem fi bers that provide support.
xylem parenchyma
are highly specialized for conduction of
water and minerals.
Tracheids and vessel elements
the chief waterconducting cells in gymnosperms and seedless
vascular plants such as ferns, are long, tapering cells located in patches or clumps.
Tracheids
these are long, tapering cells located in patches or clumps.
ferns
are thin areas in the tracheids’ cell walls where a secondary cell
wall did not form.
Pits
always occur in pairs, one on each side of the primary cell walls
of adjacent cells
Pits
Flowering plants possess efficient water-conducting cells called
vessel elements
Vessel elements are hollow, but unlike tracheids, they have holes in their end walls known as
perforations
they are hollow, but unlike tracheids, they have holes in their end
walls
Vessel elements
A stack of vessel elements, called a
vessel
resembles a miniature water pipe.
vessel
they also have pits in their side walls that permit the lateral transport of water from one vessel to another
Vessel elements
are the conducting cells of phloem
Sieve-tube elements
conducts food materials to plants
Phloem
conducts food materials—that is, carbohydrates formed in
photosynthesis—throughout the plant and provides structural support.
Phloem
In flowering plants, phloem is a complex tissue composed of four different cell types:
- Sieve-tube elements
- Companion cells
- Phloem fibers, and
- Phloem parenchyma cells
Food materials are conducted in
solution
Food materials are conducted in solution—that is, dissolved in water—through
sieve-tube elements
are among the most specialized living cells in
nature
sieve-tube elements
Sieve-tube elements are long, thin cells that are stacked end on end to form long
sieve tubes
The cell’s end walls are called
sieve plates
they have a series of holes through which
cytoplasm extends from one sieve-tube element into the next.
sieve plates
are alive at maturity, but many of their organelles, including
the nucleus, vacuole, mitochondria, and ribosomes, disintegrate as they mature.
Sieve-tube elements
Adjacent to each sieve-tube element is a
companion cell
assists in the
functioning of the sieve-tube element.
companion cell
(sing., plasmodesma)
plasmodesmata
singular form of plasmodesmata
plasmodesma
they occur between a companion
cell and its sieve-tube element.
plasmodesmata
they do not conduct nutrients itself
companion cell
it plays an essential role in loading food materials into the sieve-tube elements for transport to other parts of the plant.
companion cell
this system consists of two complex tissues
dermal tissue system
2 complex tissues in the dermal tissues system
epidermis
Periderm
In herbaceous plants, the dermal tissue system is a layer of cells called the
epidermis
but it splits apart as the plant increases in girth as a result of the production of additional woody tissues underneath the epidermis
epidermis
a tissue several to many cell layers thick, provides a new protective covering as the epidermis is destroyed.
Periderm
which replaces the epidermis in the stems and roots of older woody plants, composes the outer bark
Periderm
is the outermost layer of an herbaceous plant
Epidermis
is a complex tissue composed primarily of relatively
unspecialized living cells
epidermis
Dispersed among these cells are more specialized guard cells and outgrowths called
trichomes
are somewhat thicker toward the outside of the plant to
provide protection
Epidermal cell walls
generally contain no chloroplasts and are therefore transparent, so light can penetrate into the interior tissues of stems and leaves
Epidermal cells
is the outermost layer of an herbaceous plant
Epidermis
Epidermal cells of stems and leaves secrete a waxy layer called a
cuticle
this wax greatly restricts the loss of water from
plant surfaces.
cuticle
facilitate the diffusion of carbon dioxide.
Stomata
Stomata are
tiny pores in the epidermis between two cells called
guard cells.
The epidermis may also contain special outgrowths, or hairs, called
trichomes
occurs in many sizes and shapes and have a variety of functions
trichomes
are simple, unbranched trichomes that increase the surface area of the root epidermis for more effective water and mineral absorption.
Root hairs
(which comes into contact with the soil)
root epidermis
replaces epidermis in woody plants
Periderm
As a woody plant begins to increase in girth, its epidermis sloughs off and is replaced by
periderm
forms the protective outer bark of older stems and roots.
Periderm
are dead at maturity, and their walls are heavily coated with a
waterproof substance called suberin, which helps reduce water loss.
cork cells
(also called phelloderm)
cork parenchyma cells
function primarily in
storage.
cork parenchyma cells
Plant growth involves three different processes:
Cell division
Cell elongation
Cell differentiation
is an essential part of growth that results in an increase in the
number of cells.
Cell division
(the lengthening of a cell)
Cell elongation
new cells elongate as the cytoplasm grows and the vacuole fills with water, which exerts pressure on the cell wall and causes it to expand.
Cell elongation
or specialize, into the various cell types These cell
types compose the mature plant body and perform the various functions required in a multicellular organism.
Cell differentiation
It is considered an important aspect of
growth because it is essential for tissue formation.
Cell differentiation
are composed of cells whose primary function is the formation of new cells.
Meristems
do not differentiate. Instead, they retain the ability to
divide by mitosis, a trait that many differentiated cells lose.
Meristematic cells
persistence of ——— means that plants, unlike most animals, retain the capability for growth throughout their entire life span.
meristems
Two kinds of meristematic growth may occur in plants.
Primary growth
Secondary growth
is an increase in the length of a plant.
Primary growth
is an increase in the girth of a plant.
Secondary growth
which produces the entire plant body in herbaceous plants
and the young, soft shoot tips and root tips of woody trees and
shrubs.
Primary growth
Primary growth takes place at?
apical meristems
this area consists of meristematic cells.
root apical meristem
Directly behind the root cap, in the area of cell division, is the
root apical meristem
a protective layer and covers the root tip
root cap
where the cells have been displaced from the
meristem. Here the cells are no longer dividing but instead growing longer, pushing the root tip ahead of them, deeper into the soil.
Area of cell elongation
the cells have completely differentiated and are fully mature
Area of cell maturation
Within every bud is a dome of tiny, regularly arranged meristematic cells, the
shoot apical meristem
Three primary meristems
protoderm
Procambium
Ground meristem
is young, undifferentiated tissue of a root or stem that
eventually develops into epidermis.
protoderm
is meristematic tissue that eventually develops into xylem and
phloem.
Procambium
is meristematic tissue that gives rise to cortex, pith, and
ground tissue.
Ground meristem
(developing leaves)
Leaf primordia
emerge from the shoot apical meristem.
Bud primordia
(develop-ing buds)
Bud primordia
cover and protect the shoot apical
meristem
Leaf primordia
Secondary growth is due to cell divisions that occur in
lateral meristems
areas that extend along the entire lengths of stems and roots, except at the tips
lateral meristems
Two lateral meristems are responsible for secondary growth:
Vascular cambium
Cork cambium
is a layer of meristematic cells that forms a thin,
continuous cylinder within the stem and root.
Vascular cambium
It is located between the
wood and bark of a woody plant.
Vascular cambium
where are vascular cambiums located
between the
wood and bark of a woody plant
is a thin cylinder or irregular arrangement of meristematic
cells in the outer bark region.
Cork cambium
Cells of the cork cambium divide to form the
cork cells
3 things that make up periderm
cork cells, cork cambium, and cork parenchyma
cells that function in
storage.
cork parenchyma
Secondary growth forms secondary tissues—that is —-
secondary xylem
secondary phloem
periderm
Collectively, cork cells, cork cambium, and cork parenchyma
make up the
periderm
