Transcript Kingdom Plantae Curriculum Expectations Don`t Copy - hills

Kingdom Plantae
Overview
• Autotrophic Eukaryotes
• First group of truly multi-cellular
organisms
– Allows for specialization and organization of
structures!
– Cells Tissues Organs Organ Systems
• Organized into Divisions rather than
phyla
– 12 major divisions
Evolution
• Believed to have evolved from a freshwater
green alga
– Similarities:
• contain chlorophyll a and b
• store carbohydrates as starch
• have cell walls of cellulose
• Major evolutionary advancements include
the development of:
–
–
–
–
embryo protection
vascular tissue
seeds
flowers
Evolution – cont’d
• Fig. 29.1
Reproduction - Terminology
• Haploid (1N)
– half chromosome
count
• Diploid (2N)
– full chromosome
count
• Mitosis
– generates identical
cells
• Meiosis
– divides diploid cells to
haploid cells
• Spore
– haploid cell
– develops into a sexcell producing
structure
• Gamete
– haploid “sex cell”,
– will fuse with another
gamete
• Zygote
– First cell formed after
fusion (fertilization)
– Diploid
Characteristic Reproduction
Alternation of Generations
• ALL plants exhibit two multicellular
stages in life cycle
– Gametophyte
• Haploid (1N)
• Gamete producing stage (mitosis)
– Gametes fuse 2N zygote  sporophyte
– Sporophyte
• Diploid (2N)
• Spore producing stage (meiosis)
– Spores are 1N  develop into gametophyte
Alternation of generations
cont’d
• Fig. 29.2
Alternation of Generations cont’d
• Different plants exhibit variations of
the generalized life-cycle
– Dominant phase changes
• primitive plants = gametophyte dominant
• advanced plants = sporophyte dominant
– Only phase capable of forming vascular tissue
Alternation of Generations cont’d
Size of the gametophyte versus the sporophyte
Fig. 29.3
Bryophytes - Overview
• Non – Vascular Plants
• Lack vascular tissue
• specialized tissues or organs for transport of water
and nutrients
• Do not have true roots, stems, or leaves
• Gametophyte is the dominant generation
– Sporophyte is attached to the gametophyte
and derives nourishment from it
– Sperm must swim to egg for fertilization
• Representative Organsims
– Mosses, hornworts and liverworts
Bryophytes cont’d
• Turn and talk to your neighbour...
– What impact would these
characteristics have on the growth and
development of these plants?
Bryophytes – cont’d
• Must live in a moist environment
– Rely on diffusion and osmosis for
nutrients
• Limits the ability of the organism to
grow to a large size
– All plant parts must have direct access
to nutrients and water
Bryophytes – Structure
• Simplified plant structure
– No true organs.
• Rhizoids
– Root like filaments
• Limited anchoring
• Limited absorption
Bryophytes – Structure
• Stalk
– Elongated cells
– Helps with the osmosis of water
between cells
• Leaf-like appendages
– Large flat structures
• not a true leaf
Liverwort, Marchantia
• Fig. 29.4
Moss life cycle
• Fig. 29.5
Bryophyte Reproduction
• Asexually – fragmentation
• Sexually -
Sphagnum Moss
• AKA - Peat Moss
• Fuel source
– Can be cut into 'bricks' and used for
heating.
– Newfoundland has large peat resources
– Over millions of years peat is
compressed and forms coal
Sphagnum Moss
• Has high absorption capabilities
– Used in gardening, oil spills and diapers
• Antiseptic properties
– Very low pH
– Used as wound dressing in WWI
Vascular Plants
Vascular Plants
• Tracheophytes
– Land dwelling plants
– Have specialized structures for the
transport of nutrients and water
• Vascular Tissue!
• Artificially divided into two major
groups,
– Seedless vascular plants
– Seed plants
– Official division is into many more groups.
Division Pteridophyta
• Seedless Vascular Plants
– Representative Organisms - Ferns
Pteridophytes
• Pioneer Plants (with mosses)
– Able to grow in adverse conditions
• Bare rock, or limited soil
• Highly acidic soil, after forest fires
– Often first multi-cellular organisms to
grow in an area
• Help to create growing conditions for other
plants
Pteridophyte Structure
• Fronds
– Leafy portion
• Rhizomes
– Barely visible stem
– Grows horizontal to
surface
• Roots
• Fiddleheads
– Early stage of new
fronds
Pteridophyte
Asexual Reproduction
• Fragmentation
– Several clumps of fronds result from
one plant
– If the Rhizome connecting them is split,
each clump will survive
Pteridophyte
Sexual Reproduction
• Alternation of
Generations
• Spores produced
under fronds in
structures called
sori
Pteridophyte
Sexual Reproduction
• Gametophyte
• Gametophyte with
early development of
sporophyte
Fern life cycle
• Fig. 29.11
Vascular Seed Plants
Overview
• Plants that reproduce using seeds
• Evolutionary advantage
– Seed contains a sporophyte embryo
and stored food
• Allows survival until conditions are
favorable for germination
Overview
cont’d
• Two main groups
– Gymnosperms
• gymno = naked; sperma = seed
• ovule not completely enclosed by diploid tissue
– seeds develop on the surface of the sporophyte
– Angiosperms
• angio = vessel, receptacle, container
• ovule completely enclosed within diploid
sporophyte tissue (ovary) which becomes a
fruitseeds
Gymnosperms –
Representative Organisms
• Conifers
– Spruce, Cedar
– Grow in all climate zones
and on all continents
except Antarctica.
– Economically important
• Pulp and paper
• Gnetophytes
– Ephedra is only species
in N. America
– Adapted to hot
temperatures
Gymnosperms –
Representative Organisms
• Gingkophytes
– One surviving speciesGingko biloba, the
maidenhair tree
– Fleshy seeds give off foul
odor
– Resistant to pollutionoften used in
ornamental plantings
– Used in herbal remedies
• Cycads
– Resemble palms or ferns
– Pollen or seed cones
grow on top of long
vertical stem
– Plentiful in Mesozoic era
at the time of dinosaurs
Gymnosperms - Structure
• Generally Evergreen
– Don’t drop leaves each year
• Leaves
– Thin, needle-like
– Have thick waxy outer coat
• Roots
– Shallow roots
– Cover wide area
Conifer- Reproduction
• Conifers are dioecious
– Generate both male and female cones
• Exhibit heterospory
– Two types of spores , which produce female (♀)
and male (♂) gametophytes
– Pollen grains = ♂ gametophyte
– Pollination – deposition of pollen on a ♀
gametophyte
– Pollen tube – sperm pass through pollen tube to
reach ovule
• No water required as it is in previous groups
– ♀ gametophyte develops within ovule
Pine life cycle
• Fig. 29.12
Conifers- Adaptations
• Adapted to cold, dry weather
• Pollen cones and seed cones are
adaptations to land
• Needle-shaped leaves have small
surface area-decreases water loss
– Also have a thick cuticle and recessed
stomata
• Wood is used in construction and for
making paper
• Resins are used for production of
chemicals