Download 3.02 Plant parts

B. Plant Physiology
3.02 Discuss the anatomy and
functions of plants
14.0 Plant Parts and Their Functions
Six Major Plant Parts
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Roots
Stems
Leaves
Flowers
Fruit
Seeds
Leaves – External Parts
• Petiole
• leaf stalk or part that connects leaf to stem.
• Midrib
• Large central vein of the leaf
14.0 Plant Parts and Their Functions
Leaves – External Parts
• Blade
– the large, flat part of a leaf.
14.0 Plant Parts and Their Functions
Leaves – External Parts
• Veins
– the structural framework of a leaf.
14.0 Plant Parts and Their Functions
Leaves – External Parts
• Margin
– the edge of the leaf.
• There are several different styles (draw these)
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Entire
Serrated
Lobed
Crenate
14.0 Plant Parts and Their Functions
margin
Leaves – External Parts
• Apex
– leaf tip
14.0 Plant Parts and Their Functions
apex
Leaves – Internal Parts
• Upper and lower epidermis
– skin of the leaf that prevents the loss of too
much moisture.
14.0 Plant Parts and Their Functions
Leaves - Internal Parts
• Stomates
– small openings
under the leaf
for breathing or
transpiration.
14.0 Plant Parts and Their Functions
Leaves – Internal Parts
• Guard cells
– opens and closes the stomata.
14.0 Plant Parts and Their Functions
Leaves – Internal Parts
• Chloroplasts
– small green particles that contain chlorophyll,
gives leaves their green color and are
necessary for photosynthesis.
14.0 Plant Parts and Their Functions
Functions of the Leaf
• Photosynthesis is a process by which plants
capture sunlight and use it to convert carbon
dioxide and water into food
• Respiration converts sugars and starches into
energy
• Transpiration is the release of water vapor from
the leaves of plants
– It also cools the plant
14.0 Plant Parts and Their Functions
Leaves – Additional Notes
• Sessile
– leaves with no petiole.
Sessile
14.0 Plant Parts and Their Functions
Leaves – Additional Notes
• Bracts
– modified leaves usually found on a poinsettia.
14.0 Plant Parts and Their Functions
Leaves – Additional Notes
• Needles and scales
– Modified leaves found on a pine tree
14.0 Plant Parts and Their Functions
Leaves – Additional Notes
• Glabrous
– Leaves or stems have a smooth, non-hairy
feel
– Southern Magnolia
14.0 Plant Parts and Their Functions
Leaves – Additional Notes
• Pubescent
– Leaves or stems have a hairy feel
– African Violets
14.0 Plant Parts and Their Functions
Stem – External Parts
•
Lenticels
– breathing pores.
Stem – External Parts
• Bud scale scar
– shows where the terminal buds were located
the previous year.
Bud scale scar
14.0 Plant Parts and Their Functions
Stem – External Parts
• Leaf scar
– shows where leaves were attached.
14.0 Plant Parts and Their Functions
Stem – External Parts
• Terminal bud
– bud at the end or tip of the stem.
terminal buds
14.0 Plant Parts and Their Functions
Stem – External Parts
• Axillary bud
– Bud located at the axil of the leaf
14.0 Plant Parts and Their Functions
Stem – External Parts
• Lateral bud
– bud on the side of the stem.
lateral bud
14.0 Plant Parts and Their Functions
Stem – Internal Parts
• Xylem
– tissue that transports water and nutrients up
from roots to stems and leaves.
• Phloem
– tissue that transports food down from the
leaves to the roots.
• Cambium
– thin, green actively growing tissue located
between the bark and wood and produces
all new stem cells.
Stem – Internal Parts
Xylem
Monocot Stem:
Vascular Bundles
Heartwood
Cambium
Phloem
Bark
Dicot Stem:
Layers
Stem – Internal Parts
• Bark
– Old inactive phloem
– Protection for the stem
Stem – Internal Parts
• Heartwood
– Old inactive xylem.
14.0 Plant Parts and Their Functions
Stem – Internal Parts
• Sapwood
– New active xylem.
14.0 Plant Parts and Their Functions
Stem Structure - Cotyledons
• Monocot ~ one seed leaf
– Plant stems that have
vascular bundles that
contain both xylem and
phloem in each bundle.
– Examples: grasses, corn
• Dicot ~ two seed leaves
– plant stems have phloem
layer and a xylem layer
separated by cambium.
– Examples: trees
Vascular Bundles - Monocots
Phloem
Xylem
Top
View
Functions of the Stem
• Translocation is the movement of water
and minerals through the plant
– The phloem moves food down from the
leaves to the roots
– The xylem moves water and nutrients up from
the roots to the leaves
• Supports the branches of the plant
14.0 Plant Parts and Their Functions
Root – External Parts
• Root cap
– Located at the tip of the
root and is where new
cells are produced
• Root hairs
– absorb moisture (water)
and minerals.
14.0 Plant Parts and Their Functions
Root – External Parts
• Phloem
– the outer layer and
carries food down the
root.
• Xylem
– the inner layer and
carries water and
minerals up to the
stem.
14.0 Plant Parts and Their Functions
Types of Roots
• Fibrous
– many branched shallow roots. They are
easier to transplant.
14.0 Plant Parts and Their Functions
Types of Roots
• Tap
– long root with few branched ones, are more
difficult to transplant.
14.0 Plant Parts and Their Functions
Functions of the Roots
• Anchor the plant and hold it upright.
• Absorption – take water and nutrients
from the soil and conduct them to the
stem.
• Asexual reproduction.
• Store food for plant use.
14.0 Plant Parts and Their Functions
Flowers
• Flowers develop into seeds and fruits.
• External Parts of the Flower
– Sepals
• green parts that cover and protect flower bud
before it opens.
– Petals
• are really leaves that are modified to attract insects
for flower pollination, the pretty part that we call
flowers.
14.0 Plant Parts and Their Functions
Flowers – External Parts
petal
sepal
14.0 Plant Parts and Their Functions
Stamen - Male Parts of the
Flower
• Anther
– a sac like structure
that contains pollen,
the male sex cells.
• Filament
– short stalk that holds
up the anther
Pistil – Female Parts of the
Flower
• Stigma
– sticky part on top of style
where insects leave pollen.
• Style
– holds up the stigma and
connects it to the ovary.
• Ovary
– if fertilized becomes a fruit
or seed coat.
• Ovules
– the eggs or female sex
cells that become seeds if
fertilized.
Functions of the Flower
1. Attracts insects for
pollination.
2. Produces seeds
for sexual
propagation.
3. Produce fruit to
protect, nourish and
carry seeds.
14.0 Plant Parts and Their Functions
Flower
• Complete flower
• Pollination
– The transfer of pollen from
the anther to the stigma
– has both male and female
parts.
• Incomplete flower
• Cross pollination
– transfer of pollen from the
stamen to the stigma of
one flower to a flower on
another plant.
– has only male or female
parts.
• Fertilization
• Self pollination
– When pollen travels down
the style, joining the sperm
and the ovule
14.0 Plant Parts and Their Functions
– transfer of the pollen to the
stigma of a flower on the
same plant.
Flower Additional Notes
• Corolla
– all auxiliary part of the flower not including
reproductive organs.
– The collective term for all petals of a flower.
• Calyx
– the external usually green or leafy part of a flower.
The collective term for all sepals of a flower.
• Receptacle
– the enlarged tip of a stem on which a flower is born.
14.0 Plant Parts and Their Functions
Flower – Additional Parts
receptacle
calyx
14.0 Plant Parts and Their Functions
Additional Information
• The fruit serves as protection for the seeds
• The function of the fruit is to help with
seed dispersal
14.0 Plant Parts and Their Functions