Comparing Cells from Different
Parts of the Plant
Advanced Plant and Soil Science
(c) (14) (a)
specialization of plant structures & functions
Basic Parts of the Plant
 Roots
 Stems
 Leaves
 Flower
http://www.phschool.com/science/biology_place/biocoach/plants/basic.html
Functions of Roots
1. Anchor Plant
2. Absorb water and
minerals
3. Translocate water
and minerals to stem
4. Store Food
http://www.sparknotes.com/biology/plants/plantstructures/section2.rhtml
Functions of Stems
1. Translocate water,
minerals and food
to the leaves
2. Support the leaves
and display them to
light
3. Store Food
http://science.howstuffworks.com/dictionary/plant-terms/stem-info.htm
Functions of Leaves
1. Make food through photosynthesis
2. Provide site of gas exchange
3. Store food
http://texastreeid.tamu.edu/content/howToID/
Functions of Flowers
1. Contain organs for specialized
sexual production
2. Produce seeds and fruit
http://organicgardeningmagazine.info/flower-diagram/
Root Types
 Primary Roots
 Lateral or Secondary Roots
 Adventitious Roots
 Fibrous Roots
 Tap Roots
 Storage Roots
 Aerial Roots
Primary Root
 Definition: the first root produced by a germinating
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seed
Arises from the radicle of the seedling, which grows to
form lateral roots
Axial Structure
No Nodes and internodes
Limited area near the root tip
Lateral or Secondary Roots
 Definition: roots that grow horizontally away from the
primary root.
http://www.biologie.uni-hamburg.de/b-online/library/webb/BOT311/Roots/LateralRoots.htm
Adventitious Roots
 Definition: Roots developed from the stem that
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replace the primary root after it dies at an early stage.
These roots are equal in size
Give rise to lateral roots
Develop in places other than nodes
Can form cuttings and rhizomes
Do not undergo secondary growth
Fibrous Roots
 Definition: root structures in which the primary and
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lateral roots develop equally so that there is not a
definite taproots.
Many finely branched secondary roots
Primary root is short lived
Do not branch profusely, are shallow and spread
horizontally cannot provide strong anchorage
Main root system of monocots
Shallow roots cover a large are
 More effective absorption of water and minerals
 Roots hold the soil to prevent erosion
Tap Roots
 Definition: continuation of the primary root.
 Ideal for anchorage
 Penetration is greater for water
 Storage area for food made by photosynthesis
 Bares many branches
 Remains underground
 Usually found in dicots
http://homepage.smc.edu/hodson_kent/plant_growth/Angiosperms/ID/basics.htm
Storage Roots
 Definition: structures which are used for food storage.
 Swollen portions of primary roots or lateral roots
 Usually involves secondary growth in which the
secondary xylem or phloem become filled with food
reserves
http://www.ibguides.com/biology/notes/plant-structure-and-growth
Aerial Roots
 Definition: short roots that
grow horizontally from the
stems
 Fasten the plant to a support
 Function as prop roots or
anchorage
 More common in tropics
http://home.howstuffworks.com/growing-orchids1.htm
What are roots composed of?
 Root cap
 Apical meristem
 Region of elongation
 Region of differentiation
 Xylem
 Phloem
 Root hairs
http://extension.oregonstate.edu/mg/botany/roots.html
Definitions
 Root cap: covers the apical meristem and protects it from
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damage.
Apical meristem: region of active cell division; the
growing point of the plant.
Region of elongation: cells here grow longitudinally which
causes the root to grow longer.
Region of differentiation: the region of mature primary
tissues which is an area of active water and mineral
absorption.
Xylem: transports water and nutrients upward.
Phloem: transports carbohydrates and sugars downward.
Root hairs: increase surface area and aid in absorption.
Root Hairs
 Definition: tiny one celled
hair like extensions of the
epidermal cells located near
the tips of the roots where
vascular tissues have formed.
 Increase surface area
 Absorb water and minerals
from soil
http://www.esu.edu/~milewski/intro_biol_two/lab_5_roots_leaves/zea_root_hairs_high_magnif.html
Specialized Stems
 Corm
 Bulb
 Tuber
 Crown
 Spurs
 Rhizomes
 Stolon
http://www.infovisual.info/01/015_en.html
Corm
 Ex. Gladiolus, crocus
 Underground
 Solid, fleshy, scale covered
http://www.tutorvista.com/content/biology/biology-iii/angiosperm-morphology/underground-stem-modifications.php
Bulb
 Ex- tulips, lilies, onions
 Layers of fleshy scales that overlap each other
 Underground stem
http://www.tutorvista.com/content/biology/biology-iii/angiosperm-morphology/underground-stem-modifications.php
Tuber
 Ex- potato, caladium
 Food storage area
 Short, thick underground stem
http://withfriendship.com/user/crook/tuber.php
Crown
 Ex- African Violets, fern
 Closely grouped stems or plantlets
 Just above ground or just below
http://www.thegardenhelper.com/ubb/ultimatebb.php/topic/28/50.html
Spurs
 Ex- pear and apple trees
 Short stems found on woody plant limbs adapted for
increased production of fruits
http://extension.oregonstate.edu/mg/botany/stems4.html
Rhizomes
 Ex- iris, lily of the valley
 Underground stems
 Produce roots on the lower surface and extend leaves
and flower shoots above the ground
http://maryloudriedger2.wordpress.com/2011/11/01/a-rhizomatic-sunday/
Stolon
 Ex- strawberry, airplane plant
 Stem that grows horizontally above the soil surface
http://floridagrasses.org/Grass%20Biology.htm
Tissues of the Leaf
 Epidermis
 Mesophyll layer
 Veins or vascular layer
http://micro.magnet.fsu.edu/cells/leaftissue/leaftissue.html
Epidermis
 Cuticle
 Waxy substance covers the leaves and stems
 Waterproof layer that keeps water in plants
 Stomata
 Openings in the epidermis
 Exchange of gases
 Guard Cells
 Two cells located on each side of stomata
 Open and closes stomata
http://sbi3u1tdoust.edublogs.org/2010/06/01/
monocots-and-dicots/
Mesophyll Layer
 Palisade mesophyll
 Primary site of photosynthesis
 Spongy mesophyll
 Contains air and chloroplasts
 Site of photosynthesis and gas
exchange
Veins or vascular bundles
 Located in spongy mesophyll
 Phloem tissues conduct food from
photosynthesis to rest of plant
 Xylem tissues conduct water and
minerals up to cells in leaves and stems
Parts of a Flower
 Peduncle
 tip of the stalk where the flower begins
 Receptacle
 starts at the peduncle and acts as a base to
which all other parts of the flower are
attached
Parts of a Flower
 Sepals
 Outer covering of the flower bud
 Protects the stamens and pistils when flower is in bud
stage
 Collectively called calyx
 Petals
 Inner whorl of leaves
 Protects stamen and pistils
 Attracts pollinating insects
 Known collectively as the corolla
Male Reproduction: Flower
 Stamen
 Male organs
 The number per flower varies
 Composed of two parts:
 Anther- produces pollen
 Filament- supports the anther
Female Reproduction: Flower
 Pistil
 Female organs
 There can be one or more
 Three parts:
 Stigma- holds the pollen grains and is sticky
 Style- connects the stigma to the ovary
 Ovary- enlarged portion at base of pistil and produces ovules
which develop into seeds
http://www.sparknotes.com/biology/plants/plantstructures/section5.rhtml
References
 Comparison of Root, Stem and Leaf Structure and Function in Dicots. (n.d.).
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Welcome to Hillfield Strathallan College. Retrieved May 21, 2012, from
http://www.hsc.on.ca/moffatt/bio3a/plantphys/rootstem.html
Primary Root Structure and Development . (n.d.). EEOB. Retrieved May 21,
2012, from www.eeob.iastate.edu/classes/bio454/docs/404root104.pdf
Root Structure and Function. (n.d.). Botanical Science . Retrieved May 21,
2012, from
www.cartage.org.lb/en/themes/sciences/botanicalsciences/plantsstructure/RootsS
tructure/RootsStructure.htm
Root System. (n.d.). BIO. Retrieved May 21, 2012, from
www.nios.ac.in/srsec314newE/PDFBIO.EL6.pdf
The Structure of Plants . (n.d.). The Structure of Plants . Retrieved May 21,
2012, from
homepage.smc.edu/hodson_kent/plant_growth/Angiosperms/ID/basics.htm
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