Kingdom: Plantae
Post on 23-Feb-2016
39 Views
Preview:
DESCRIPTION
Transcript
Kingdom: Plantae
What is a plant?
• Multicellular• Eukaryotic• Cell wall made of cellulose• Develop from multicellular embryos• Carry out photosynthesis• Contain chlorophyll a and b to trap
sunlight.
Life Cycle of Plants• Plant life cycles have
2 alternating phases, a diploid (2n) and a haploid (n) phase, known as alternation of generations.
HaploidDiploid MEIOSIS
Spores(N)
Sporophyte Plant (2N)
Gametophyte Plant (N)
FERTILIZATION
Sperm(N)
Eggs(N)
What plants need to survive?
• Sunlight• Water and minerals• Gas exchange (stomata)• Transport of water and nutrients (xylem
and phloem)
Groups of Bryophytes
• This group lacks vascular tissue therefore it uses diffusion and osmosis to obtain nutrients.
• Mosses Which do not have true roots instead have rhizoids.
• Liverworts• Hornworts
Seedless Vascular Plants
Comparing Spore-Bearing Vascular Plants
CharacteristicsWatertransportation
Structure
Club MossesBy vasculartissue
Look like miniature pine trees; scalelike leaves
HorsetailsBy vasculartissue
True leaves, stems, and roots
FernsBy vasculartissue
Creeping or underground rhizomes (stems); fronts (leaves); some have no roots or leaves
Seed PlantsComparing Features of Seed Plants
FeatureSeeds
Reproduction
Examples
Gymnosperms Angiosperms
Bear their seeds on cones
Can reproduce without water; male gametophytes are contained in pollen grains; fertilization occurs by pollination
Conifers, cycads, ginkgoes, gnetophytes
Bear their seeds within flowers
Can reproduce without water; male gametophytes are contained in pollen grains; fertilization occurs by pollination
Grasses, flowering trees and shrubs, wildflowers, cultivated flowers
are categorized as
that completetheir life cycle in
that completetheir life cycle in
that completetheir life cycle in
Concept Map
Plants
Annuals Biennials Perennials
1 growingseason 2 years
More than2 years
Monocots Dicots
Seeds
Leaves
Flowers
Stems
Roots
Single cotyledon
Parallel veins
Floral parts often in multiples of 3
Vascularbundlesscattered throughout stem
Fibrous roots
Two cotyledons
Branched veins
Floral parts often in multiplesof 4 or 5
Vascularbundlesarranged ina ring
Taproot
Comparison ofMonocots and Dicots
Seed Plant Structures
include
includes includes includes
includes includes
Plant Tissues
Dermaltissue
Meristematictissue
Vasculartissue
Groundtissue
Epidermalcells Xylem Phloem Parenchyma
cellsCollenchyma
cellsSchlerenchyma
cells
Tracheids Vesselelements
Sieve tubeelements
Companioncells
Plant Tissue Systems• Dermal Tissue: consists of epidermal cells that
cover the outer surface.• Vascular Tissue: specialized transport cells1. Xylem: carries water and nutrients up from the
roots. (tracheids and vessel elements)2. Phloem: carries sugars down from leaves
(sieve tube elements and companion cells)• Ground Tissue: contains photosynthesizing
cells and cells that help make plants strong.
Plant Growth
• Meristems are clusters of cells at the tips of roots and stems that are responsible for the growth throughout a plant’s life.
• The new cells produced are called meristematic tissue.
• Apical meristems are located at the tip or end of the root and stem that produces new cells by the process of mitosis.
RootsEpidermis
Ground tissue(cortex)
VascularCylinder
Cross Section of Plant Root(magnification: 40x)
Ground tissue (cortex)
Epidermis
EndodermisVascular cylinder
Root hairs
Phloem
Xylem
Apical meristem
Root cap
Zone of maturation
Zone of elongation
Endodermis
Function and Types of Roots• The roots job is absorb water and
nutrients form the soil and anchor the plant in the ground.
• Types:1. Taproot a long root that extends deep
into the ground.2. Fibrous root: branching root help prevent
topsoil erosion.3. Some plants have both types of roots.
Leaf Structure
Veins
XylemPhloem
Vein
Cuticle
Epidermis
Palisademesophyll
Epidermis
Stoma
Guardcells
Spongymesophyll
Leaf Function
• Stomata: gas exchange• Guard cells: open and close the stomata• Mesophyll: contain cells that carry out
photosynthesis.
Transpiration• The pull of water
from the roots to the leaves of the plant
Factors that increase transpiration:
1. Increase temperature
2. Increase wind3. Decreased humidity
Sugar Movement in Plants
Movementof water
Movementof sugar
Sugarmolecules
Source cell
Sink cell
Phloem Xylem
Reproduction with Cones
Reproduction with Flowers
FilamentAnther
StigmaStyle
Ovary
Carpel
PetalSepalOvule
Stamen
Stamens: the male portionOf the flower1. anther: produces pollen2. filament
Carpel (Pistil): female Portion of the flower.1. ovary: contains the ovules.2. stigma: sticky tip that pollen attaches to.3. style: creates the Pollen tube that allowsPollen to reach the eggs.
Haploid (N)
Diploid (2N)
MEIOSIS
FERTILIZATION
Cycle of an Angiosperm
Ovule
Anther (2N) Pollen grains (N)(male gametophyte)
Pollentubes
Haploid cell(N)
Embryo sac (N)(female gametophyte)
Egg cellSperm
Pollen tubeEndosperm nuclei
Endosperm(3N)
Zygote(2N)FruitSeed coat
Endosperm
Embryo(2N)Seedling (2N)
(new sporophyte)
Maturesporophyte
Ovary
Style
Stigma
Comparing Wind-pollinated and Animal-pollinated Plants
CharacteristicsPollination method
Relative efficiency of pollination method
Plant types
Reproductive organs
Adaptations that promote pollination
Wind-pollinatedPlantsWind pollination
Less efficient
Mostly gymnosperms and some angiosperms
Cones
Pollination drop
Animal-pollinated PlantsVector pollination
More efficient
Angiosperms
Flowers
Bright colors, sweet nectar
Wind vs. Animal Pollination
Seed Dispersal
• Animals: sweet, fleshy fruits (blueberries) • Wind and water: lightweight, allowing them
to be carried by air or float in water. (tumbleweeds)
Seed Germination
Plant Hormones• Chemical substances that control a plant’s
patterns of growth and development, and the plant’s responses to environmental conditions.
• Auxin: stimulate cell elongation• Gibberellins: increase size of stems and
fruit• Cytokinins: stimulate cellular division • Ethylene: Stimulate the ripening of fruit.
Auxin and phototropism
Control Tipremoved
Opaquecap
Clearcap
Opaque shiedover base
Highconcentration
of auxin
Lowconcentration
of auxin
Auxin production of the shaded side of plant causes it to Bend towards the light.
Auxin and Gravitropism
Auxin causes stems to grow up and roots to grow down in Response to gravity.
Apical meristem
Lateral buds
Apical meristem removed
Auxins produced in the apical meristeminhibit the growth of lateral buds.
Without the inhibiting effect of auxinsfrom the apicial meristem, lateral budsproduce many branches.
Auxin and Branching Apical Dominance
Auxin-like Weed Killers
• High concentrations of auxins inhibit plant growth.
• Scientists have engineered herbicides like 2,4-D that mimic the hormone auxin and thus kill weeds.
Plant Reponses
• Phototropism: response to light• Gravitropism: response to gravity• Thigmotropism: response to touch
PhotoperiodismMidnight
NoonLong Day
Midnight
NoonShort Day
Midnight
NoonInterrupted Night
Short-Day Plant Long-Day Plant
Photoperiodism:Is reponsible for The timing ofSeasonalActivities such asFlowering and growth
The response To flowering Is controlled byThe amountOf darkness thePlant receives
Winter Dormancy
• As cold weather approaches, deciduous plants turn off photosynthetic pathways, transport materials from leaves to roots, and seal off leaves from the rest of the plant.
Adaptations
• Chemical defenses: manufacture compounds that have a powerful effect on animals. Ex. Aspirin, tobacco
• Epiphytes: Grow on trees to reach sunlight.
• Succulents: reduces leaves, extensive roots, thick stems. (cacti)
• Carnivorous Plants: digest insects.
top related