Chapter 16 Plant Structure and Function - by huangyuarong


									 Chapter 16 Plant Structure and

16.1 Root, Stem, Leaf: Structure
         and Function
    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
               lignin) is
          a)   phloem
          b)   sapwood
          c)   cortex
          d)   heartwood
• Leaves generally have a                 surface to
  expose chloroplasts to maximum sunlight.
• Chloroplasts are generally                  packed
  near a leaf’s upper surface for maximum
  sunlight exposure.
• 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
  some               .
• 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
    inner cells
•                    : 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
a)    epidermis
b)    cuticle
c)    cork
d)    lignin
            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.
• 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
  external air
• 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
  a) osmosis
  b) photosynthesis
  c) transpiration
  d) capillary action

Aphids have been useful in helping scientists
 a) sugar translocation
 b) guttation
 c) leaf pull
 d)    None of the above.
The rate of transpiration in trees
        is dependent on
a) air temperature
b) humidity
c) wind velocity
d) All of the above.
Which of the following statements is true regarding the rise of water
 in plants?
 a) Plants must expend energy to move water from the ground to
 the leaves
 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

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