Chapter 16 Plant Structure and
16.1 Root, Stem, Leaf: Structure
Did you know that most ( %) of the
water taken in by the roots is lost through
• All root tissues : To the plant
• Root hairs (epidermal tissue) :
Transport and .
• Epidermis, cortex, endodermis, ground or
fundamental tissue. : Transport water and
minerals to tissue
• : an underground stem
specialized for food storage; a potato is the
most common example.
• : a specialized, fleshy
stem that grows on or just below the
• : an underground stem encased
in leaf-like tissues, specialized for storage.
The tissue in woody dicot stems that
fills with complex chemicals (such as
• Leaves generally have a surface to
expose chloroplasts to maximum sunlight.
• Chloroplasts are generally packed
near a leaf’s upper surface for maximum
• Waterproof , especially on upper
surfaces. Reduces water loss through
evaporation. Generally, stomata are on the lower
leaf surface to better control water loss.
• Generally, layers have many
air spaces to facilitate gas exchange within the
• use of light energy to convert carbon
dioxide and water into carbohydrates,
carried out by the chloroplasts of and
• Stomata are usually on the surface to
prevent excess water loss through evaporation.
• There is a higher level of , generally more
around the lower surface than the upper so evaporation
rate is reduced.
• There can be better control of loss with
stomata on lower surfaces.
: a class of plants that produce flowers
• : short for monocotyledon, a
class of flowering plants whose seeds have one
seed leaf (grains and grasses)
• : short for dicotyledon, a class of
flowering plants whose seeds have two seed
leaves (daisy, tomato, maple tree)
• : one cell layer thick, outermost layer of the
root; absorbs water and minerals from the soil and protects the
• : layer of cells found just below the epidermis;
store molecules of starch, help transport water and minerals
from the epidermal cells to the center of the root
• : a specialized wax-coated cell layer of the
• : surrounds the endodermal cells; prevents
water from moving around them
• : transport water and minerals to the leaves
• : transport sugars from the leaves to the other
parts of the plant
• : xylem closer to center, and phloem is
closer to outside
• : in between xylem and phloem in dicots
• : waxy substance covering leaves;
produced by epidermis
• : allows water vapour, oxygen, and carbon
dioxide to move in and out of leaf
• : contain chloroplasts; open in day
and closed at night
• : cells within leaf, which contain
• : densely packed and contain more
• : loosely packed
• : the process of water loss through
evaporation in leaves
The waterproof secretion on plant leaves and green stems is
16.2 Plant Tissues and Their Functions
• Do you think that plants take in water and “food”
(nutrients) through the roots? Food is manufactured
by the plant, not taken in. Plants take in ________
(often referred to as nutrients); plants do not take in
• Most people do not know that much of is
living tissue and most people have no clue where
cork comes from (i.e., the source).
• : A water-resistant protective layer, dead
at maturity, produced in the outer regions of stems
and roots of woody plants.
One can distinguish spring xylem from summer xylem by the fact
that spring xylem cells are
a) longer than summer xylem
b) smaller in diameter than summer xylem
c) larger in diameter than summer xylem
d) living, whereas summer xylem cells are not
16.3 Water and Food Transport
• Transpiration pull is dependent upon a
continuous column of water in the .
• If breaks in the water column in a vessel
occur, as they do, then theoretically upward
water transport in that vessel .
• However, it is thought that trees overcome
this situation by having water
move from vessels in which a
break may have occurred, to an adjacent
vessel via pits. Thus, a continuous water
column is maintained.
HOW IS WATER
TRANSPORTED UP THE
• as water is absorbed
into the cell, the
volume of cytoplasm
increases so pressure
in the cell increases
takes place because of of water
molecules and walls of xylem turn upwards
walls are closer together and water and
dissolved minerals move up the .
root pressure (in ) and capillary
action (in ) allow water and
minerals to go up
• Transpiration is the evaporation of water vapour from
plant via the .
• Most of the water comes directly from the xylem and
evaporates into the intercellular spaces of the spongy
layer of the leaf and then through the stomata to the
• Because water is , the water molecules in
the xylem are connected
by so the upward movement of
water causes another water molecule to move into the
root (by osmosis) as one leaves the leaf
Adhesion of water to cell surfaces
is one of the factors involved in
a) translocation of sugars in phloem
b) the rise of water in stems
c) root pressure
d) active transport in sieve tube cells
Bryophytes do not rely on
d) capillary action
Aphids have been useful in helping scientists
a) sugar translocation
c) leaf pull
d) None of the above.
The rate of transpiration in trees
is dependent on
a) air temperature
c) wind velocity
d) All of the above.
Which of the following statements is true regarding the rise of water
a) Plants must expend energy to move water from the ground to
b) The ascent of water is fastest when the stomata are closed.
c) The ascent of water is fastest at night.
d) Transpiration is required to lift water to the tops of tall plants.
The fact that root pressure cannot be demonstrated in some plants
a) that it does not exist
b) it is not a major factor in moving up plants
c) it is the main force causing water to rise in plants
d) that roots may not be involved in moving water up plants