Download File - Classes with Mrs. Sheetz

Kingdom Plantae: Introduction,
Structure, and Function
Intro
• Trees, grasses, flowers, ferns, and mosses
• Primary producers on earth:
-contribute oxygen, carbon fixation
> 250,000 species
• Botany: the study of plants
• Classified by their structure
• Structure: see figure 24.2.1 on page 508
• Organelles: see figure 24.2.2 on page 508
Characteristics:
• Cell wall:
-made of cellulose
• Primary cell wall:
-first cell wall made, surrounded by a layer of
pectins
-forms middle lamella
• Secondary cell wall:
-woody plants
-adds more structural support
-contains lignins
• Plasmodesmata
-small channels that connect plant cells to one
another (share nutrients & water)
Vascular and Nonvascular Plants
• Vascular plants:
-use a system on interconnected tubes to
transport water and nutrition
-examples: trees, flowers, grasses, bushes, etc.
Xylem: transport water & minerals from roots to
rest of the plant
Phloem: transports glucose (nutrition) from
photosynthesis to all parts of the plants
• Nonvascular plants:
-grow in moist environments, small in size
-no tube network, use diffusion
-examples: mosses, liverworts, and hornworts
General Plant Reproduction
• Reproduce by spores, seeds, both, or neither
• Used to classify plants
• Spore
-small, one cell, no protective coating
• Seed
-larger, multicellular, protective coating
-contain embryo + endosperm
Monocots & Dicots
Three General Plant Tissue Types
• Parenchyma: unspecialized tissue, found
throughout the plant
• Collenchyma: thicker primary cell walls,
provide structural support
• Sclerenchyma: thick secondary cell walls, fill
with lignin and become wood
Vegetative organs: roots, stem, leaves
Reproductive organs: flower, cone, etc.
Meristem Tissue:
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Specialized tissue where growth takes place
Tips of roots and stems
Apical meristem = growth in length
Lateral meristem = growth in girth
Roots
• Anchor plant; absorb water and minerals from
the soil
• Two types of root systems:
taproot – one main root
fibrous – many roots of equal size
• Layers:
Epidermis, cortex, endodermis, pericycle
Vascular cambium: contains xylem & phloem
Stem
• Leaves or branches form at the nodes
• Monocot vs. Dicot (page 518)
Bark
• Layers: inner bark, cork cambium, outer bark
• Outermost protective layer of woody stems
• Growth rings: rings of dead xylem cells; tell
age, health, climate
Leaves
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Primary photosynthetic organ of plant
exchange gas, absorb sunlight
Monocot: veins run parallel
Dicot: veins are netted
• cuticle: waxy covering, limits
water loss
• Guard cells close the stomata (openings) to
limit water loss
Importance of Water in Plants
• Necessary for photosynthesis, turgor pressure,
hydrolysis, and transport
• Turgor pressure: keeps stems upright and
leaves full
– Water is drawn into the central vacuoles by
osmosis
Nastic movements: movement due to changes in
plant’s environment as a result of changes in turgor
pressure.
Water and Transportation
• Critical for transport of nutrients and food
throughout the plant
• Cohesion-tension theory:
water molecules “stick” together
• Translocation: movement of
glucose from leaves to rest
of plant