Download Unit 5: Plant Science

Unit 5: Plant Science
Mr. Nagel
Meade High School
Warm Up
• What significant roles do plants perform on
Earth? How do you know?
• Name two modern issues that could be
interrelated with plants.
IB Syllabus Statements
• 9.1.1
– Draw and label plan diagrams to show the distribution of tissues in the
stem and leaf of a dicotyledonous plant.
• 9.1.2
– Outline three differences between the structures of dicotyledonous and
monocotyledonous plants.
• 9.1.3
– Explain the relationship between the distribution of tissues in the leaf
and the functions of these tissues.
• 9.1.4
– Identify modifications of roots, stems and leaves for different functions:
bulbs, stem tubers, storage roots and tendrils.
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http://click4biology.info/c4b/9/plant9.htm
Damon, Alan, et al. Pearson Baccalaureate: HL Biology. Pearson, 2007. 238-246.
Print.
Hierarchy
• Organize and describe the following terms:
– Level 1
• Non-vascular land plants
• Seedless Vascular Plants
• Seeded Vascular Plants
– Level 2
• Gymnosperms
• Angiosperms
– Level 3
• Dermal Tissue
• Ground Tissue
• Vascular Tissue
Hierarchy
• Level 1
• Non-vascular land plants
– No conducting tissue; small and grow close to the ground
» Ex: Mosses, Liverworts, and Hornworts
• Seedless Vascular Plants
– Well-developed vascular tissue; no seed production
» Ex: Horsetails, Ferns, Club Mosses, and Whisk Ferns
• Seeded Vascular Plants
– Most living plants are in this group; extensive vascular system
• Level 2
• Gymnosperms
– Have seeds that do not develop within an enclosed structure
• Angiosperms
– Have seeds that develop within a protective structure
• Level 3
• Dermal Tissue
– Outer protective covering protects against physical agents and pathogenic
organisms; prevents water loss and may be specialized for various purposes
• Ground Tissue
– Thin-walled cells that function in storage, photosynthesis, support and secretion
• Vascular Tissue
– Xylem and Phloem carry out long-distance conduction of water, minerals, and
nutrients within the plant, while providing support.
Plan Diagrams
Root Tissue
Stem Tissue
Leaf Tissue
Mono vs. Di
Monocots
Dicots
Embryo
One cotyledon
Two cotyledons
Veins
Parallel venation in
leaves
Netlike venation in leaves
Flowers
3 flower parts or
multiples
4 or 5 flower parts or
multiples
Vascular
System
Vascular bundles
arranged throughout
stem
Vascular bundles
arranged as a ring in the
stem
Root
System
Mainly fibrous
Taproot (main root) with
surrounding fibers
Pollen
One opening on pollen
grain
Three openings on pollen
grain
Cotyledon: Leaf that emerges from a seed.
Homework
Consider the LEAVES, ROOTS, and
STEMS of various plants. Consider the
variation that exists in these structures as
you go from plant to plant.
• Identify FOUR observed differences in
each ‘organ’, with examples to support
your observations.
– Produce a simple bubble map to organize
your thoughts.
Warm Up
• Compare and contrast Monocots with
Dicots on three characteristics.
• Identify the three main groupings that all
plants fall into. Provide an example of
each.
• What roles do the xylem and phloem play
in the plant?
IB Syllabus Statements
• 9.1.4
– Identify modifications of roots, stems and leaves for different functions:
bulbs, stem tubers, storage roots and tendrils.
• 9.1.5
– State that dicotyledonous plants have apical and lateral meristems.
• 9.1.6
– Compare growth due to apical and lateral meristems in dicotyledonous
plants.
• 9.1.7
– Explain the role of auxin in phototropism as an example of the control of
plant growth.
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•
http://click4biology.info/c4b/9/plant9.htm
Damon, Alan, et al. Pearson Baccalaureate: HL Biology. Pearson, 2007. 238-246.
Print.
Plant Organ Mods - Roots
• Roots
– Prop roots
• Thick adventitious roots that grow from the lower part of the
stem to brace the plant.
• Ex: Corn
– Storage roots
• Specialized cells within the root store large quantities of
carbohydrates and water.
• Ex: Carrot, Beet
– Air roots (pneumatophores)
• Produced by plants that live in wet places, these roots extend
above the soil or water surface and facilitate oxygen uptake.
• Ex: Mangrove, Cyprus tree
– Buttress roots
• Large roots that develop near the bottom of trees to provide
stability.
• Ex: Fig tree
Plant Organ Mods - Stems
• Stems
– Bulbs
• Vertical, underground stems consisting of enlarged bases of
leaves that store food.
• Ex: Onion
– Tubers
• Horizontally growing stems below ground that are modified as
carbohydrate-storage structures.
• Ex: Potatoes
– Rhizomes
• Horizontal stems that grow just below the surface to allow plant
spreading.
• Ex: Ginger
– Stolons
• Horizontal stems growing above ground that allow plant to
reproduce asexually.
• Ex: Strawberry plants
Plant Organ Mods – Leaves
• Leaves
– Tendrils
• Structures that coil around objects to aid in support and climbing
(sometimes modified stems).
• Ex: Pea plants produce tendrils from leaves
– Reproductive leaves
• Produce tiny plants along the leaf margins that fall to the ground
and take root in the soil.
• Ex: Kalanchoe plants
– Floral leaves / bracts
• Colored modified leaves that surround flowers and attract
insects for pollination.
• Ex: Poinsettia
– Spines
• Reduce water loss, may be associated with modified stems that
carry out photosynthesis.
• Ex: Cacti
Meristems
• What are they?
• What type of cells are similar in animals?
• What is different about a meristem as
compared to these animal cells?
Meristems
• Two types
– Apical
• Primary growth
• Root tips and stems (length)
• Herbaceous, non-woody stems and roots
– Lateral
• Secondary growth
• Increased thickness of plants (width)
• Woody plants (shrubs, trees)
– Vascular cambium  secondary vascular tissue
produces secondary xylem on the inside (wood
component) and secondary phloem on the outside
– Cork cambium  bark produces cork cells of outer bark
Phototropism
• Define phototropism.
• What hormone is responsible for this
behavior?
• What parts of the plant exhibit high levels
of this hormone?
• Is the hormone produced in greater
quantities or redistributed within the plant?
• How do high concentrations of this
hormone facilitate growth TOWARD a light
source?
HW Questions
• Why would girdling (the removal of bark
and vascular cambium in a narrow ring all
the way around a tree) result in the death
of the tree?
• If you remove the apical meristem from a
dicotyledonous plant, what would be the
effect on further plant growth?
• Of what value are tubers, a type of stem
modification, to the survival of the plant
species?
Transpiration
• http://www.sciencemag.org/site/feature/mi
sc/webfeat/vis2005/show/transpiration.swf
http://alex.edfac.usyd.edu.au/Methods/HSIE/Ayca/untitled/xerophyt.htm
Warm Up
• Name three environmental factors that will
increase the rate of transpiration.
• What plant part/feature has the most direct
influence on the rate of transpiration?
• What is the purpose of root hairs?
IB Syllabus Statements
• 9.3.1
– Draw and label a diagram showing the structure of a dicotyledonous animalpollinated flower.
• 9.3.2
– Distinguish between pollination, fertilization and seed dispersal.
• 9.3.3
– Draw and label a diagram showing the external and internal structure of a named
dicotyledonous seed.
• 9.3.4
– Explain the conditions needed for the germination of a typical seed.
• 9.3.5
– Outline the metabolic processes during germination of a starchy seed.
• 9.3.6
– Explain how flowering is controlled in long-day and short-day plants, including the
role of phytochrome.
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http://click4biology.info/c4b/9/plant9.htm
Damon, Alan, et al. Pearson Baccalaureate: HL Biology. Pearson, 2007. 256-261.
Print.
Anatomy of a Flower
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Sepals
Petals
Anther
Filament
Stigma
Style
Ovary
Anatomy of a Flower
• Sepals
– Protect developing flower while in the bud
• Petals
– Colorful to attract pollinators
• Anther
– Part of stamen which produces ‘male’ pollen
• Filament
– Stalk of stamen that holds up anther
• Stigma
– Sticky top of carpel (pistil) where pollen lands
• Style
– Part of carpel that supports
• Ovary
– Base of carpel where ‘female’ sex cells develop
Birds and the Bees…
• Pollination
– Process of pollen being placed on the female
stigma
– Leads to…
• Fertilization
– Male and female sex cells unite to form a
diploid zygote
– Leads to…
• Seeds! (inside juicy fruit)
Seeds
• Require oxygen, water, and appropriate
temperature
Light-sensitive Plants
Plant Type
Flowering and light
Examples
Long-day
Radishes, spinach, and
lettuce
Short-day
Poinsettias,
chrysanthemums, and
asters
Day-neutral
Roses, dandelions, and
tomatoes