What is a Plant? 1. Multicellular 2. Eukaryotic 3. Cell walls of cellulose 4. Carry out...
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Transcript of What is a Plant? 1. Multicellular 2. Eukaryotic 3. Cell walls of cellulose 4. Carry out...
What is a Plant?What is a Plant?
1. Multicellular1. Multicellular
2. Eukaryotic2. Eukaryotic
3. Cell walls of 3. Cell walls of cellulosecellulose
4. Carry out 4. Carry out photosynthesisphotosynthesis
5. Store 5. Store energyenergy as as starchstarch
6. Autotrophic6. Autotrophic
ADAPTATIONS TO SURVIVE ON LANDADAPTATIONS TO SURVIVE ON LAND
1.1. To prevent water loss, many plants have–To prevent water loss, many plants have–
A. A. Waxy cuticle Waxy cuticle – thick layer for protection– thick layer for protectionB. B. Stomata Stomata – Open during day; close at night; – Open during day; close at night;
regulated by guard cells regulated by guard cells
2. 2. LeavesLeaves are specialized for are specialized for photosynthesisphotosynthesis
*Shape to trap light energy *Shape to trap light energy
*Gas exchange occurs here*Gas exchange occurs here
Organ of photosynthesis
is the leaf!
What is theorganelle?
3. Specialized roots for 3. Specialized roots for absorption of water absorption of water and minerals and minerals
4. Specialized 4. Specialized stemstem for for transporting transporting materials materials
5. Reproduction on lands needs to occur 5. Reproduction on lands needs to occur with little or no water with little or no water
****MANY PLANTS PRODUCE SPORES
****AND SOMEPRODUCE SEEDS
Evolution of Plants
• Using the following words, put them in order of how you think they evolved….
EVOLUTIONARY PERSPECTIVE OF EVOLUTIONARY PERSPECTIVE OF DEVELOPMENTDEVELOPMENT
OF PLANT TYPES:OF PLANT TYPES:
ALGAE ALGAE MOSSES MOSSES FERNS FERNS
CONE-BEARING CONE-BEARING FLOWERINGFLOWERING
TWO MAIN CATEGORIES OF TWO MAIN CATEGORIES OF PLANTS :PLANTS :
1. NONVASCULAR1. NONVASCULAR 2. VASCULAR2. VASCULAR
Examples of Nonvascular Plants -Examples of Nonvascular Plants -
LIVERWORTS
MOSSES
No vascular tissue!No vascular tissue!
Water moves by osmosisWater moves by osmosis
Low-growingLow-growing
Include 3 Main Groups:
A. Ferns(Seedless)
B. Gymnosperms (Seeds in cones)
C.Angiosperms (Seeds in flowers)
A. XYLEM - Cells in tubes that transport water and minerals
B. PHLOEM - Tubes that transport food
SugarsActively transported; water also moves(By osmosis)through the phloemfrom the SOURCE to the (Place thatstores or uses sugars) SINK
**PRESSURE FLOW HYPOTHESIS
Movementof water
Movementof sugar
Sugarmolecules
Source cell
Sink cell
Phloem Xylem
Phloem Transport
Vascular Plants Include 3 Main Groups:
A. Ferns(Seedless)
B. Gymnosperms (Seeds in cones)
C.Angiosperms (Seeds in fruits, Produce flowers)
A.Ferns –
Seedless Vascular plants
Require water for sperm to swim to egg
Leaves calledfronds
B. Gymnosperms
Vascular plants
Produce seeds on scales called cones
“Naked seeds”
***Water not neededfor reproduction
Pollen grain contains gametophyte and sperm!
Carried to female cone by wind, water, insects, ... (Pollination)
****Pollen grows tube to join egg
(fertilization) forming seed
Life cycle of gymnosperm
Most produce seeds in woody
cones
Female (seed)and
Male (pollen)cones
Seed coat
Embryo
Storedfood supply
Seed
Wing
A
B
The Structure of a Seed
AFTER FERTILIZATION
Zygote becomes an EMBRYO (Diploid sporophyte)
COTYLEDONS – Seed leaf of embryo
SEED COAT – Protects embryo
Advantages of Seeds
*Food supply for growing plant*Protection by seed coat*Provides less competition with “parents”*Water not needed for fertilization
Largest Group of Gymnosperms are the Conifers
Needle – Like leaves help retain water
Flexible branches and needles so they don’t
break with the weight of snow!
A few are DECIDUOUS (Lose their leaves at
same time) so are dormant in winter
Most are EVERGREEN so can carry on
photosynthesis as soon as spring arrives
Grow tall because of wood tubes (tracheids) that
support water and dissolved minerals
Are these xylem or phloem???
**Bark reduces water loss
WHAT ARE ANGIOSPERMS?
VASCULAR PLANTSVASCULAR PLANTS
PRODUCE FLOWERSPRODUCE FLOWERS
DEVELOP SEEDS IN DEVELOP SEEDS IN FRUITS FRUITS WHICH HELPS PROTECT EMBRYOWHICH HELPS PROTECT EMBRYO
TWO CLASSES OF ANGIOSPERMS:
1. Monocots• One seed leaf in embryo
• Includes grasses, orchids, lilies, palms
•Parallel veins in leaves
• Flower parts in multiples of three
2. Dicots
• Two seed leaves in embryo
• Most flowering plants
• Leaves with netted veins
• Flower parts in multiples of four
or five
Monocot vs. Dicot
MonocotMonocot DicotDicot
CotyledonsCotyledons
(seed leaves)(seed leaves)
Mono=1Mono=1 Di=2Di=2
Leaf VeinsLeaf Veins ParallelParallel BranchedBranched
Flower Parts Flower Parts (#petals, (#petals, stamen, stamen, carpels, etc)carpels, etc)
Always in Always in multiples of 3multiples of 3
(ex. 3, 6, 9)(ex. 3, 6, 9)
In multiples of In multiples of 4s and 5s4s and 5s
RootsRoots fibrousfibrous Tap rootTap root
Monocot or Dicot????
Monocots vs. Dicots
Absorption
Support; transport
Photosynthesis
Contain xylem and phloem
Two types of root systems:
A. TAPROOT SYSTEM – Large central roots, Ex: Carrot! (most dicots)
1. Roots
B. FIBROUS ROOT SYSTEM – Highly branched (Most monocots)
ROOT HAIRS increase surface area for absorption
ROOT CAP - Covers tip of the root and protects it
MERISTEM – Growth area just behind the root tip
~Was this primary or secondary growth?
Epidermis
Ground tissue(cortex)
VascularCylinder
Cross Section of Plant Root(magnification: 40x)
Ground tissue (cortex)
Epidermis
Endodermis
Vascular cylinder
Root hairs
Phloem
Xylem
Apical meristem
Root cap
Zone of maturation
Zone of elongation
Endodermis
Structure of a Root
2. STEMS
Two kinds –
A. HERBACEOUS – Flexible vascularbundles scattered
B. WOODY –
Rigid
Havegrowthrings of vasculartissue thatdetermine age
Wood Bark
Cork
Cork Cambium
Phloem
Vascular Cambium
Xylem: Sapwood
Xylem:Heartwood
Layers of a Tree Trunk
Contains old, nonfunctioningxylem that helpssupport the tree
Contains active xylem that transports water and minerals
Produces new xylem and phloem, which increase the width of the stem
Transports sugars produced by photosynthesis
Produces protective layer of cork
Contains old, nonfunctioning phloem that protects the tree
3. LEAVESA. SIMPLE – One leaf blade attached to stem
B. COMPOUND – Divided leaf blade attached to stem
PETIOLE – stalk that attaches leaf to stem
Cross Section of a Typical Leaf
MESOPHYLL – Ground tissue full of chloroplasts
PHLOEMXYLEM
GUARD CELLSTOMA
Epidermis
Cuticle
Guard cell
Stomata
Structure of a leaf: STOMATA
Structure of a Flower
1. SEPALS –
Leaflike; green; arranged in circle beneaththe petals
*Protectsthe ovary!
*Protects theFlower whileDeveloping!
2. PETALS –
Leaf-like and colorful to attract insects!
3. STAMEN – MALE!
Male part made of ANTHER and FILAMENT
Anther: produces pollen (sperm!)
Filament: stalk that supports the anther
4. PISTIL/CARPEL – FEMALE!
Female part made of sticky STIGMA (where pollen grains land), STYLE (transports sperm to egg), and OVARY which contains OVULES with eggs inside
COMPLETE FLOWER – Has all four
organs
INCOMPLETE FLOWER –
Lacks one or more organs
What is this picture missing?
FilamentAnther
StigmaStyle
Ovary
Carpel
PetalSepal
Ovule
Stamen
The Structure of a Flower
POLLINATION –
Transfer of pollen from the stamen to the pistil
Adaptations for Pollination that Attract Particular Animals:
1. Nectar2. Petal Color3. Scent
Types of Pollination
1. SELF-POLLINATION – Stigma receives pollen from the same plant
2. CROSS-POLLINATION2. CROSS-POLLINATION – – • POLLEN FROM ONE PLANTPOLLEN FROM ONE PLANT IS CARRIED TO STIGMA OF IS CARRIED TO STIGMA OF ANOTHER OF SAME TYPE OF ANOTHER OF SAME TYPE OF PLANT PLANT
• ALLOWS FOR EXCHANGE OFALLOWS FOR EXCHANGE OF GENETIC MATERIALGENETIC MATERIAL
After the pollen grain lands on the stigma, the pollen tube cell grows a tube to the ovary.
The two spermcells move through thetube intothe ovule
-One sperm joinswith the egg in theOvule.
-The other spermjoins with the central cell (2N) toform the endosperm (3N).
This process is called double fertilization!!!
Seed Formation
After fertilization occurs, the flower dies and the seed develops.
Ovule becomes the seed coat which protects the embryo.
The zygote divides becoming the embryo.
The 3N central cell develops into the endosperm which is food-storage tissue.
Fruits
The ovary develops into
the fruit!
Parts of a Seed
Fruits can be dry (Nuts and grains)or
Fleshy (Oranges, Peaches Tomatoes, Squash,…)
***Fruits protect the seeds and aid in dispersal***
Seed Germination
Seeds remain dormant until conditions are right for development and growth!
****GERMINATION – Development of the seed into a new plant!
Water, oxygen, and warm temperatures are Needed!
Root appears first, then the stem,
and finally the leaves
Growth and Development
Plants respond to stimuli from the environment This process is called TROPISM
POSITIVE TROPISM – growth towards the stimulusNEGATIVE TROPISM – growth away from the stimulus
PHOTOTROPISM – Response to light GRAVITROPISM –
Response to gravity
THIGMOTROPISM – Response to touch
PLANT HORMONES
HORMONES – Chemicals made in one part of an organism that cause a change somewhere else
*Produced in ROOTS!
AUXINS – Growth hormones; cause cells to elongate, inhibit growth of sidebranches
Control Tipremoved
Opaquecap
Clearcap
Opaque shiedover base
Highconcentration
of auxin
Lowconcentration
of auxin
Auxins and Phototropism
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.
Apical Dominance
TAKS Review1. How are chloroplasts and mitochondria
alike?a. Get energy directly from the sunb. Found in humansc. Found in plantsd. Responsible for energy conversions
2. Plants give off oxygen in what process?a. Photosynthesisb. Aerobic respirationc. Chemosynthesisd. Anaerobic respiration
TAKS Review Cont….1. Production of Carbon Dioxide and sugar2. Production of Oxygen and sugar3. Exposure to light4. Breakdown of protein5. Intake of carbon dioxide6. Intake of oxygen
Three of the statements above are stages in photosynthesis. Select and arrange in order 3 stages of photosynthesis. a. 3-4-1b. 4-3-2c. 3-5-2d. 3-6-1
TAKS Review Cont….4. What are the function of stomata?
a. sugar production
b. protection
c. gas exchange
d. water storage
5. What is the function of xylem? Phloem?
a. transport water; transport food
b. transport food; transport water