lecture 3: plant anatomy and...
TRANSCRIPT
![Page 1: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/1.jpg)
Plant anatomy
![Page 2: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/2.jpg)
From smallest to largest plants
![Page 3: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/3.jpg)
What is plant anatomy?
• ANATOMY: study of the structure of
organisms… looking at cells, tissues
![Page 4: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/4.jpg)
• How can water
move from
the ground
all the way
to the top
of a 100 m
tall redwood
tree?
![Page 5: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/5.jpg)
Plant Anatomy: Cells
• Plant cells are basic building blocks
• Can specialize in form and function
• By working together, forming tissues, they can
support each other and survive
• Levels of organizationatoms > molecules > cells > tissues > organs > whole plant > pop.
![Page 6: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/6.jpg)
Plant Tissues Types
All plant organs (roots, stems, leaves) are
composed of the same tissue types.
There are three types of tissue:
• 1. Dermal – outermost layer
• 2. Vascular – conducting tissue, transport
• 3. Ground – bulk of inner layers
![Page 7: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/7.jpg)
1. Dermal tissue
• Epidermis is the outermost layer of cells
• Like the “skin” of animals
• In stems and leaves,
epidermis has cuticle,
a waxy layer that prevents
water loss.
• Root epidermis has root hairs, for
water and nutrient absorption
![Page 8: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/8.jpg)
2. Vascular tissue
• Transports water and organic materials (sugars)
throughout the plant
• Xylem – transports water and
dissolved ions from the root
to the stem and leaves.
• Phloem – carries dissolved sugars
from leaves to rest of the plant
![Page 9: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/9.jpg)
Xylem• Transports water and dissolved minerals
• Tracheids: long, thin tube like structures
without perforations at the ends
• Vessel elements: short, wide tubes perforated at
the ends (together form a pipe, called vessel).
• Both cells have pits (thin sections) on the walls
Tracheids Vessel elements
![Page 10: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/10.jpg)
Xylem cells
• Xylem cells are dead!
• They are hollow cells
and consist
only of
cell wall
![Page 11: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/11.jpg)
Phloem
• Cells that transport organic materials (sugars)
• Phloem cells are ALIVE! (unlike xylem)
• However, they lack
nucleus and
organelles
![Page 12: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/12.jpg)
Phloem: transports sugars
• Phloem composed of cells called sieve tube
members (STM)
• Companion cells join sieve tube members, are
related, and help to load materials into STM
• End walls of STM have large pores called
sieve plates
Sieve tube member
Companion cells
Sieve plates
![Page 13: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/13.jpg)
3. Ground tissue• Makes up the bulk of plant organs.
• Functions: Metabolism, storage and support.
Root Stem Leaf
![Page 14: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/14.jpg)
Plant OrgansOrgans: tissues that act together to serve a
specific function
• Roots
• Stems
• Leaves
Dermal
Vascular
Ground
Dermal
Vascular
Ground
Dermal
Vascular
Ground
![Page 15: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/15.jpg)
Functions of plant organs:
• ROOTS: Anchorage, water/nutrient absorption
from soil, storage, water/nutrient transport
• STEMS: Support, water/nutrient transport
• LEAVES: Photosynthesis (food production)
![Page 16: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/16.jpg)
ROOTS
• ROOTS “the hidden half”
• Functions of roots:
• Ancorage
• Absorption of water & dissolved minerals
• Storage (surplus sugars, starch)
• Conduction water/nutrients
![Page 17: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/17.jpg)
Anatomy of a root
epidermiscortex
vascular
![Page 18: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/18.jpg)
Root Epidermis• Outermost, single layer of cells that:
– Protects (from diseases)
– Absorbs water and nutrients
• ROOT HAIRS: tubular extensions
of epidermal cells.
• Increase surface area of root,
for better water/nutrient
absorption
![Page 19: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/19.jpg)
Root Hairs: water and mineral
absorption
Root hairs
increase surface
area for better
absorption
![Page 20: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/20.jpg)
Root Cortex• Stores starch, sugars and other substances
![Page 21: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/21.jpg)
Root Ground tissue
• In roots, ground tissue (a.k.a. cortex)
provides support, and
often stores sugars and starch
(for example: yams, sweet potato, etc.)
Hey!
I yam
what I
yam,
man!
You’re not a
yam, you’re a
sweetpotato!
cortex
![Page 22: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/22.jpg)
STEMS
• Above-ground organs (usually)
• Support leaves and fruits
• Conduct water and sugars
throughout plant (xylem and phloem)
![Page 23: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/23.jpg)
Stem anatomy
• Dermal, ground and vascular tissues…
pith
cortexepidermis
Vascular
bundles
![Page 24: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/24.jpg)
Types of Stems
Monocot stem Dicot stem Root
![Page 25: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/25.jpg)
Types of stems
• Herbaceous vs. Woody stems
![Page 26: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/26.jpg)
Tissues of stems
• Epidermis (Dermal tissue type)
• Provides protection
• Has cuticle (wax) prevents water loss
• Trichomes (hairs) for protection, to release
scents, oils, etc.
![Page 27: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/27.jpg)
Stem Vascular tissue
• Vascular bundles – composed of both
xylem and phloem
• Xylem
– Conducts water
– Support
• Phloem
– Conducts food
– Support
Vascular
cambium
![Page 28: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/28.jpg)
Vascular cambium
• Occurs in woody stems
• Vascular cambium located in the middle of
the vascular bundle, between xylem and
phloem
![Page 29: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/29.jpg)
Vascular tissue: Trees
• Vascular tissue is located on the outer layers
of the tree.
wood
phloem
xylem
bark
Vascular
cambium
![Page 30: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/30.jpg)
Vascular tissue forms rings in trees
• Annual rings: xylem formed by the
vascular cambium during one growing
season
• One ring = one year
![Page 31: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/31.jpg)
History of the tree: annual rings
1489: Tree is planted
by Native American
1492: Columbus lands in
the Americas
1620: Pilgrims land
in Plymouth, Mass.
1776: Declaration
of US independence
1861: Start of
Civil War
1969: Man
lands on Moon
1917 & 1945: Tree
Survives two World
Wars
1971: Birth Year
of the IDIOT
who cut down
this tree!!!
Dendrochronology : tree time-keeping
![Page 32: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/32.jpg)
LEAVES:
• ‘Photosynthetic factories’ of the plant…
• Function: Photosynthesis – food
production for the whole plant
• Blade: Flat expanded area
• Petiole: stalk that connects
leaf blade to stem, and
transports materials
BLADE
![Page 33: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/33.jpg)
Leaf Anatomy
• Leaf anatomy is correlated to photosynthesis:
Carbon dioxide + Water sugars + oxygen
dermal
ground
vascular
dermal
![Page 34: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/34.jpg)
Leaf epidermis
• Is transparent – so that sun light can go through.
• Waxy cuticle protects against drying out
![Page 35: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/35.jpg)
Leaf epidermis
• Stomata open and close, by the guard cells.
• Lower epidermis: stomata with guard cells
– for gas exchange (CO2, H2O in; O2 out)
![Page 36: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/36.jpg)
Leaf vascular tissue
• VEINS vascular tissue of leaves.
• Veins are composed of xylem (water transport)
phloem (food transport)
and bundle sheaths,
cells surrounding the
xylem/phloem for
strength & support
![Page 37: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/37.jpg)
Leaf Mesophyll
• Middle of the leaf (meso-phyll)
• Palisade (long columns below epidermis;
have lots chloroplasts for
photosynthesis)
Spongy parenchyma
(spherical cells)
with air spaces around,
(for gas exchange)
![Page 38: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/38.jpg)
Plant water transport
• How can water move from
the ground
all the way
to the top
of a 100 m
tall redwood
tree?
![Page 39: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/39.jpg)
Water transport in plants:
• The same way we drink soda
from a straw!
• Water’s great
cohesive forces (molecules
sticking to each other)
and adhesive forces
(attaching to walls of xylem cells)
![Page 40: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/40.jpg)
Transpirationfor water transport in the xylem
• Evaporation of water in the leaves
(through stomates) generates the ‘sucking
force’ that pulls adjacent water molecules
up the leaf surface
![Page 41: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/41.jpg)
Water transport (cont.)
• Like a long chain, water molecules pull each
other up the column.
• The column goes from roots leaves.
• What’s amazing is that the
water moves up by using the sun’s
evaporative energy…
• Plants control transpiration by opening/closing
stomata
![Page 42: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/42.jpg)
Plant Hormones
• Chemical compounds produced by plants
• Effective at very low concentrations
• Five major hormone groups are:
1. Auxins
2. Gibberellins
3. Cytokinins
4. Abscisic Acid
5. Ethylene
![Page 43: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/43.jpg)
1. AUXINS• Promote cell growth
• Involved in
gravitropism
and phototropism
• Control fruit development
![Page 44: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/44.jpg)
2. Gibberellins
• Promote stem elongation
3. Cytokinins• Promote cell division and
organ differentiation
4. Abscisic Acid• Promotes seed dormancy
• Causes stomata closing
![Page 45: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/45.jpg)
5. ETHYLENE
• Gaseous hormone,
very simple formula (C2H4)
• Ethylene promotes
fruit ripening!
Air Ethylene
![Page 46: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/46.jpg)
“One rotten apple spoils the barrel”
• Why?
Probably due to ethylene!
Rotten apple producing
lots of ethylene!
• Autocatalytic
• As a response to injury
![Page 47: Lecture 3: Plant anatomy and physiologyswampteacher.weebly.com/.../0/5/0/90502337/plant_anatomy.pdfPlant Anatomy: Cells • Plant cells are basic building blocks • Can specialize](https://reader034.vdocument.in/reader034/viewer/2022042305/5ed10e6188fb5b013b527392/html5/thumbnails/47.jpg)
Avocado ripening…
• Place in a paper bag, with a ripe banana!