Transcript File

Objective 3.02
• Discuss the
anatomy and
functions of
plants.
Leaves-External
• Petiole-Leaf stalk or part that connects
the leaf to the stem
• Blade-The large, flat part of the leaf
• Midrib-The large center vein
• Veins-The structural framework of the
leaf
• Margin-The edge of the leaf
• Apex – Leaf Tip
Leaves-External
Leaves-Internal
• Upper and lower epidermis-skin of
the leaf that prevents the loss of
too much moisture
• Stomates-small openings under
the leaf for breathing or
transpiration
• Guard Cells-open and close
stomates
Leaves-Internal
• Chloroplasts-small green particles that contain
chlorophyll
– gives leaves their green color
– necessary for photosynthesis
Leaves-Internal
Leaves-Internal
Leaves-Functions
• Photosynthesis
– 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
– release of water vapor from the leaves of
plants
– It also cools the plant
Photosynthesis vs. Respiration
Leaves-Additional Terms
• Sessile describes leaves without
a petiole
– Example zinnia
• Bracts are modified leaves
– Example poinsettia
• Needles and scales are modified
leaves
– Example pine tree
Leaves-Additional Terms
Leaves-Additions
• Glabrous leaves or stems have a smooth nonhairy feel
– Example southern magnolia
• Pubescent leaves or stems have a hairy feel
– Example African violet
Stems-External
• Lenticels-breathing pores found on
stems and branches
• Bud scale scars-show where terminal
buds have been located
• Leaf Scars-show where leaves were
attached
• Terminal bud-bud on the end of a stem
• Axillary bud- bud located at the leaf axil
• Lateral bud- bud on side of stem
Stems-External
Stems-External
Stems-Internal
• Xylem-tissue that transports water and
nutrients up from the roots to stems and leaves
• Phloem-tissue that transports food down from
leaves to roots
Stems-Internal
Stems-Internal
Phloem
Phloem
Xylem
Stems-Internal
• Cambium-thin, green, actively growing tissue
located between bark and wood and produces
all new stem cells
• Bark-old inactive phloem
• Heartwood-old inactive xylem
• Sapwood-new active xylem
Stems-Internal
Stems-Internal
Bark
Cambium
Sapwood
Heartwood
Stems-Internal
• Monocots-plant stems have vascular bundles
that contain both xylem and phloem in each
bundle. Produce one seed leaf.
– examples: corn, grasses
• Dicots-plant stems have the phloem layer and
xylem layer separated by cambium. Produce
two seed leaves
– example: trees, many vegetable plants
Stems-Internal
Monocot
Dicot
Stems-Internal
Stems-Functions
• Translocation- the movement of water and
minerals through the plant
• Phloem moves food down from leaves to
roots
• Xylem moves water and nutrients up from
roots to leaves
• Stems provide support for the branches of
the plant
Roots-External
• Root cap- located at the tip of the root and is
where new cells are produced
• Root hairs-absorb moisture (water) and
minerals
Root
images
from a rice
plant
Roots-Internal
• Much like stems in that they have a phloem,
cambium, and xylem layer
• Phloem-the outer layer that carries food down
the root
• Xylem-the inner layer that carries water and
minerals up to the stem
Types of Roots
• Fibrous-many branched shallow roots
– are easier to transplant
• Tap-long root with few branched ones
– more difficult to transplant
Functions of Roots
• Anchorage
• Absorption
• Asexual reproduction (propagation)
• Storage
Flowers
• 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
• Stamen-male part of the flower
• Pistil-female part of the flower
Flowers
Parts of the Stamen
• Filament-short stalk that
holds up the anther
• Anther-a sac-like structure
that contains pollen, the
male sex cells
Parts of the Pistil
• Ovules-the eggs or female sex cells that
become seeds if fertilized
• Ovary-if fertilized becomes a fruit or seed coat
• Style-holds up the stigma and connects it to
the ovary
• Stigma-sticky part on top of style where insects
leave pollen
Parts of the Pistil
Stigma
Style
Ovary
Functions of Flowers
• Attracts insects for pollination
• Produces seeds for sexual reproduction
• Produces fruit to nourish and protect the seed
Additional Flower and Fruit Terms
• Complete flower- has both male and female
parts
• Incomplete flower- has only male or female
parts
Additional Flower and Fruit Terms
• Fertilization – when pollen travels down the
style, joining the sperm and the ovule
• Pollination – transfer of pollen from the anther
to the stigma
• Cross-pollination – transfer of pollen from the
stamen to the stigma of one flower to a flower
on another plant
• Self-pollination – transfer of the pollen to the
stigma of a flower on the same plant
Additional Flower and Fruit Terms
• Corolla – all auxiliary parts of the flower not
including reproductive organs
– Collective term for all petals of a flower
• Calyx – external, usually green or leafy part of a
flower
– Collective term for all sepals of a flower
• Receptacle – enlarged tip of stem on which a flower
is borne
• Fruit serves as protection for seeds
• Function of fruit is to help with seed dispersal
Types of Fruits
• Pome – fleshy fruit which has a central core
that usually has 5 seeds and is surrounded by a
thick outer layer.
– Ex: apples, pears
• Drupe – fleshy fruit which has one seed
enclosed in a hard, stony material
– Ex: plum, peach, cherry
Types of Fruit
• Berry – entire ovary that is fleshy and often
juicy with thin skin
– Ex: tomato, grape
• Modified Berry – like a berry but with a tough
covering
– Grapefruit, cucumber
Types of Fruits
• Aggregate fruit – compound fruit of many tiny drupes
clustered on a single receptacle
– Ex: blackberry, raspberry
• Accessory fruit – small and hard, scattered over the
surface of the receptacle. The edible part forms an
enlarged receptacle with seeds usually on the outside
– Ex: Strawberry
• Multiple fruit – compound fruit formed from several
flowers in a cluster
– Ex: pineapple, mulberry
REVIEW OF FUNCTIONS!
What are the
functions of these
plant parts?
Functions of Leaves
• Photosynthesis-manufactures food in green plants
which is the beginning of the food chain for all living
things
• Photosynthesis is the process by which carbon dioxide
and water in the presence of light are converted to
sugar and oxygen
Functions of Stems
• Translocation-moves water and minerals from
roots up to the leaves and move food from the
leaves down to the roots
• Supports branches, leaves, flowers, fruits and
seeds
Functions of Roots
• Absorption-take water and
nutrients from the soil and
conduct them to the stem
• Anchor the plant and hold it
upright
• Store food for plant use
• Asexual reproduction in some
plants
Functions of Flowers
• Produce seeds used for
sexual reproduction
• Attract insects for pollination
(Pollination is the transfer of
pollen from anther to
stigma.)
• Produce fruit to protect,
nourish and carry seeds