TO DO
Label the cross section of the leaf on your
worksheet
Chloroplast
Lower epidermis
Upper epidermis
Cuticle
Guard cells
Carbon Dioxide
Stoma
Air Spaces
Spongy Mesophyll
Palisade Mesophyll
Oxygen
 What does this mean?
• That they can produce there own energy
 Two types of plants
• Produce seeds eg. Flowering plants
• Don’t produce seeds eg mosses and ferns
 Land plants require???
• Water
• Carbon dioxide
• Oxygen
• Sunlight
Shoot system
• organs above
ground: leaves,
stems and
reproductive
organs (flowers
and seeds)
Root system
• organs below
ground: roots
and root hairs

Plants have specialised cells and tissues for particular
roles such as:
• storage, structure, transport, photosynthesis, respiration,
growth and reproduction.
• Important tissues include
1. Meristematic tissue
2. Dermal tissue including root hairs
3. Ground tissue includes all internal cells except vascular
tissue
4. Vascular tissue
 Cells
division by mitosis for
growth
 Found at the root, shoot
tips and ring around the
inside of stem and branches
 Cells differentiate into
whatever type of
cell/tissue is required.
 Allowing Growth in length
and width

is the outer most layer of cells in plant tissues, eg.
eipdermis layer
• Protects the plant body from cuts, invasion by microorganisms
and water loss.

Epidermal tissues include:
• Waxy cuticle on leaves for protection
• Fine hairs on roots for water absorption

Internal plant cells
(under the epidermal
cells) other than the
vascular tissue
• Storage – starch
• Support
• Photosynthetic
Transport of substances throughout plant
 Two
main types: xylem and phloem
 transports
water and nutrients from
roots to the rest of the plant
 in one direction only (roots to leaves)
 mature cells are dead and have open
ends to conduct water ‘tubular
skeletons’



Transports sugars (sucrose) and other materials from
leaves to other parts of the plant
Phloem cells are living
Two types of phloem cells: sieve cells and companion
cells
• Sieve cells
 no nucleus
 share cytoplasm
 pass materials between sieve cells through sieve plates
• Companion cells
 have a nucleus and cell organelles to control each sieve cell
Sucrose enters phloem through
diffusion. Water enters phloem
from xylem through osmosis
companion cell
sieve cell
 What
are the four different types of
tissues found in plants?
 What do each do?
 Create a table to compare xylem and
phloem.
Root system



Anchoring
Uptake of water and nutrients
Fine root hairs increase surface area for more
effective uptake
Root pressure
water enters roots by osmosis, dissolved minerals
(ions) enter roots by diffusion and active transport
 the pressure of osmosis, diffusion and active
transport forces water and mineral ions into and up
the xylem cells

Shoot system
Water moves up through xylem cells, sugars move
down through phloem cells
 Xylem and phloem cells are found together in
vascular bundles
 Vascular bundles are arranged differently in each
section of the plant




Continuous upwards
movement of water is driven
by the evaporation of water
from the leaves
The constant loss of water
by plants through leaves is
called transpiration
The upward movement of
water is aided by:
• Adhesion; attraction between
water molecules and the
inside walls of xylem vessels
• Cohesion; forces of attraction
between individual water
molecules
 The
movement of glucose from where it
is synthesised (photosynthesis in leaves)
to other parts of the plant
Explain the forces that enable water in a
xylem vessel to reach the top of a tree?
 Stomata
control the movement of carbon
dioxide in and water and oxygen out of
leaves.
 Stomata are tiny pores found
mostly in the lower epidermis of
leaves
 Stoma open when guard cells
absorb water and close when
they lose water
 Stomata open in moist conditions
and close in dry conditions,
controlling the amount of evaporation
 Through
what structure does gas
exchange occur in plants?
 What is the function of the stomata?
 Draw a diagram to show how the stomata
open and close
 Under what environmental conditions are
stomata most likely to be open?
 How do stems and roots exchange gases
with the environment?
 Deciduous
plants: leaves before autumn
 Into bark that will peel or drop off
 Dead cells to form lignin (woody centre)
 Exude resins, fats, waxes or latex