Transcript Plants Spring

Plant Structure & Function
Mrs. Griffin
Photosynthesis Review
• Cross Section of Leaf
Photosynthesis Review
• Equation?
Light
– 6H2O + 6CO2 ----------> C6H12O6+ 6O2
• What do plants give us?
• Site for gas exchange?
– Stomata
Introduction to Plants
• Multicellular or unicellular?
• Carry out photosynthesis using the
green pigments chlorophyll a and b
• What do plants need to survive?
– Sunlight, H2O & minerals, gas exchange
movement of water and nutrients
Early Plants
• The first plants evolved from
organisms much like the green algae
living today
– Photosynthetic pigments
– DNA sequence, close relationship
– Fossils- similarities to today's mosses
Bryophytes
• Mosses & their relatives are generally
called bryophytes, or NONVASCULAR, plants.
• Depend on water for reproduction
• Why non-vascular?
• Draw water up by
osmosis
Mosses, liverworts, hornworts
Seedless Vascular Plants
• Fossil evidence shows ~420 million
years ago moss-like plants were
joined w/ other plants species
• These new plants were the 1st to have
a transport system w/ vascular tissue
• What is the function of vascular
tissue?
– Transport water & nutrients
Vascular Tissue
• Tracheids are the key
cells in xylem, the
transport system that
carries water upward
from roots
• Phloem, second
vascular tissue that
transports nutrients
and carbohydrates
produced by
photosynthesis.
• Transpiration?
Seed Plants
• Over 1 million years plants with the
capability to form seeds became the most
dominant group of photosynthetic
organisms on land.
Seed Plants
• Gymnosperms
bear their seeds
directly on the
surface of cones
• Angiosperms,
“flowering plants,”
bear their seeds
w/in a layer of
tissue that protects
the seed
Angiosperms: Flowers & Fruits
• Angiosperms, “enclosed seed,”
develop unique reproductive organs
known as flowers
• Flowers contain ovaries, which
surround and protect the seeds
• Fruit- a wall of tissue surrounding the
seed
Flowering Parts
Stigma
Anther
Style
Pollen
Ovary
Filament
Ovules
Sepal
Petal
Stamen
Pistil
Diversity of Angiosperms
• Incredibly diverse group….
• Categories provide a way of organizing
diverse angiosperms
• Two classes w/in angiosperms:
monocotyledons (monocots) &
dicotyledonae (dicots)
• Names for the number of seed leaves, or
cotyledons in the plant embryo.
Diversity of Angiosperms
• Monocots have one seed leaf, and
dicots have two
• Cotyledon is the 1st leaf or 1st pair of
leaves produced by the embryo of a
seed plant
Characteristics of Monocots & Dicots