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Water and Land as Habitats for Plants. Aquatic Plants. Terrestrial Plants. Under land surface, evaporates quickly above surface. Water. Close to each cell. On or under surface. Minerals. Close to each cell. Gases. Dissolved at low concentrations. Plentiful in air. Aquatic Plants.
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Water and Land as Habitats for Plants Aquatic Plants Terrestrial Plants Under land surface, evaporates quickly above surface Water Close to each cell On or under surface Minerals Close to each cell Gases Dissolved at low concentrations Plentiful in air
Aquatic Plants Terrestrial Plants Support Provides buoyancy and support Much less support for parts in air More light available Cuts out some wavelengths and lowers intensity Light Changes more rapid, wider extremes Little fluctuation, slow change Temperature
Aquatic Plants Terrestrial Plants Reproduction Gametes swim to other plants Water seldom available for swimming gametes Offspring Dispersal Water carries offspring to new locations Offspring dispersed through various methods (seldom water)
Terrestrial Plant Anatomy Roots STEMS LEAVES
Plants moved from water to land but there were challenges along the way… Adaptation Challenge Getting water and minerals into the plant Roots
Major Functions of Roots Absorption Transport of materials Storage of materials Anchorage
Fibrous root Taproot
All of these things add to the Surface Area which allows for more water to be absorbed Meristem area where new cells are added to a plant, increasing its length
Fibrous root Taproot
Terrestrial Plant Adaptations Adaptation Challenge Getting water and minerals into the plant Roots Moving water and food within the plant Vascular tissue
Phloem “Ph”lows “Ph”ood DOWN!!!! Xylem carries H2O & minerals UP
Vascular tissue Bundles of xylem and phloem are found in roots, stems and leaves of vascular plants
Adhesion Water “sticks” to other molecules
- Cohesion – Water “sticks” to water + Adhesion – Water “sticks” to other molecules (Starts the process) + - - - + + + Transpiration – Water loss from a plant leaf + + +
Vascular tissue Bundles of xylem and phloem are found in roots, stems and leaves of vascular plants
2 main types of vascular plants • Gymnosperms – cone bearing plants • Pine trees and fir trees • Angiosperms – flowering plants • Any tree, bush or plant that produces a flower
Within the Angiosperms, there are two plant groups, the Monocots and the Dicots. The distinction between these two groups is not always clear, but some general trends are outlined on then next slide
MonocotsDicots Floral Arrangement 3's 4's and 5's Leaf Venation Parallel Net Vascular bundles Scattered Ring Roots Fibrous Taproot Growth Primary only Primary and Secondary Examples: Grass, Palm, Oaks, Roses, Orchid Sunflowers
Terrestrial Plant Adaptations Adaptation Challenge Getting water and minerals into the plant Roots Moving water and food within the plant Vascular tissue Plant body support Vascular tissue
Major Functions of STEMS Support Transport Storage
MERISTEMS – Regions of cell division @ tips of plant • PRIMARY GROWTH - growth in length of plant • SECONDARY GROWTH - Growth in thickness of plant
Terrestrial Plant Adaptations Adaptation Challenge Getting sunlight for photosynthesis Leaves
LEAVES • Most are thin & flat (surface area to volume ratio) • Take in sunlight & CO2
Terrestrial Plant Adaptations Adaptation Challenge Getting sunlight for photosynthesis Leaves Getting gas for photosynthesis and cellular respiration Stomata
STOMATA pore that allows CO2 to enter and H2O & O2 exit. Transpiration – Loss of H2O by plant > 90% of H2O is lost Through stomata GUARD CELLS open & close the stomata Some plants in dry climates will regulate when the stomata is open to minimize water loss
Terrestrial Plant Adaptations Adaptation Challenge Getting sunlight for photosynthesis Leaves Getting gas for photosynthesis and cellular respiration Stomata Preventing evaporation from plant surface Cuticle
Cuticle– waxy layer • Prevent H2O loss
Terrestrial Plant Adaptations Adaptation Challenge Coordinating growth patterns and environmental response Hormones Getting sperm to egg without water Pollen
Plant Reproduction Sexual Asexual Sperm from one plant fertilized the eggs of another plant of the same species Sperm (pollen) carried by wind, insects, animals, etc. New combination of DNA in offspring A plant reproduces by itself. There is no combining of DNA Runners (roots), leaves, self-pollination Offspring = genetically identical to parent plant Clones!
Female Parts Carpel Stigma Style Ovary Male Parts Stamen Filament Anther
Terrestrial Plant Adaptations Adaptation Challenge Coordinating growth patterns and environmental response Hormones Getting sperm to egg without water Pollen Airborne spores then seeds Dispersing new individuals to suitable locations