Download 3rd grade - FLOWERS: Reproductive plant parts

3rdgrade-FLOWERS:Reproductiveplantparts
objective:Studentswilllearntoidentifykeypartsofaflowerbydissectingrealflowers
inthegardensuchaspetuniasandnasturtiums.Theywillunderstandtherolesthose
partsplayinplantreproduction:howfertilizedflowersproduceseeds.
supplies:enoughexamplesofperfectflowers(bothmaleandfemaleparts)suchas
petunias,fuchsias,nasturtiums,etc.forstudentstodissectaloneorinpairs.
time:45min
5minoverview:generalplantknowledge
Gaugestudentpriorknowledge:whyareplantsimportant?Whatdotheydoforus
humans?Whatdowecallapersonwhostudiesplants?(botanist–botanyisthestudy
ofplants).Holdupaplantyankedoutofgroundandaskaboutplantpartsandtheir
purpose:
roots–dowhat?anchorplant/absorbnutrients&water
stem–supportsplant,holdsitupright(stability)
leaves–photosynthesis–energyfromsun
flower–makesseeds(reproduction)
whatisaseed?–babyplant(embryoinside)
(Kory)10-15min:tourofflowersingarden
Takestudentsonashortwalkthroughgardenandpointoutdifferentkindsofflowers–
promptquestions:whydotheyalllookdifferent?Dotheyallhavethesameparts?No–
somearesimple(justoneflower)andsomearecomposite(lotsofminiflowersinside),
someareperfect(havemaleandfemaleparts)andsomeimperfect(onlyoneorother
sex).Let’slookatexamplesofeach!
1.(Sandy)ShowstudentsaMirabilisor4O’Clockflowerwhichisasimpleflower–it
makesjust1seed!Nowlookatasunflowerandexplainthateachsunflowerheadis
madeupofmanysmallflowers-acompoundflower-withrayfloretsontheoutside
anddiscfloretsinthecenter.Breaktheflowerintwoandletthemexaminetheinside.
Showthemseedsforming.Marigoldsarealsocompoundflowers.Seemanyseeds!
http://www.backyardnature.net/fl_marig.htm.
http://www.ehow.com/how_8591681_describe-parts-sunflower.html
http://urbanext.illinois.edu/gpe/case4/c4facts1a.html
http://www.ehow.com/facts_4798758_parts-sunflower.html
2.(Kory)Showstudentssquashorbegoniaflowers–theyareimperfect-Imperfect
flowershaveeithermaleorfemalepartsbutnotboth–theymustcrosspollinateto
makeseeds!Squashplantsmakebothkindsofflowers.Ifthesameplantcross
pollinatesyougetapumpkin–butwhathappenswhenapumpkincrosseswitha
zuchinni?Yougetaweirdzumpkin!That’shownewvarietiesappearinnature!
http://www.gardeningknowhow.com/edible/vegetables/squash/female-male-squash-blossoms.htm
“Begonia plants are monoecious, with unisexual male and female flowers occurring
separately on the same plant; the male contains numerous stamens, and the female has a
large inferior ovary and two to four branched or twisted stigmas.”
Somefruitandnuttreesareeithermaleorfemalesoyoumustplanttwotreestomake
suretheycancrosspollinateeachotheroryouwon’tgetanyfruit!Showstudentsthe
hopsplant–thisonlyhasthefemaleflowers–notmale!Sonoseedsproducedinthis
garden!https://en.wikipedia.org/wiki/Hops
http://fruitandnuteducation.ucdavis.edu/generaltopics/AnatomyPollination/Flower_Anatomy/
3.(Sandy)ShowstudentssomeexamplesofPerfectflowers(liketomatoor
nasturtiums)whichhavebothmaleandfemalepartsinthesameflower–thesecanself
pollinate!Let’slookmorecloselyattheirparts.
15-20min:dissectingflowers
(Kory&Sandy)Drawadiagramoffloweronwhiteboardorsidewalkorschoolbrickwall
andwhiledrawingaskstudentstolabelpartsandtalkaboutthepurposeofthoseparts:
Petals–showycolorfulpart–attractspollinators
Sepals–likegreen‘leaves’ofthefloweratbase
Pistil(femalepart)includes:
Ovary–hasovules(eggs)insidethatwillbecomeseedsoncefertilized
Style–longtubethatholdsthestigma–pollengrainstraveldowntofertilizeovary
Stigma–stickypartattopofpistilthatpollensticksto
Stamen(malepart)includesboth:
Filament–skinnylongthreadthatholds/supportstheAnther
Anther–haspollenontop
(Sandy&Korybreakclassinto2groups)
Studentseachreceiveanasturtiumflower(ifenoughtogoaround!Ortheyworkin
pairs)andtoldtheseareedibleflowers.Demonstratehowtobreakapartandfindall
parts.Studentsdissecttheirnasturtiumsandiftheycanidentifyallthepartstheymay
eatwhatthey’vedissected–nasturtiumshaveapepperyflavor!Seeifstudentscanfind
nasturtiumseedsformingontheplantsingarden.ORstudentseachreceiveapetunia
flower(notedible!)todissect.
**Expansion**
Onpicnictables,layoutvariousexamplesofdifferentseedshapes,eachseedtypeona
plate–Theseseedswerealltheresultoffertilizedflowers!Askstudentstorecalltheir
seeddispersalknowledgeandaskthemtoguesshoweachseeddispersesandhowthey
know–someseedsmightdisperseinmultipleways!
Alsolayoutbookorprintswithpicturesofoldbotanicaldrawingsofcrosssectionsof
plantsshowingflowersandseeds.Explaintostudentsthatbeforetherewerecamerasor
film,scientistsalsohadtobeartists!TellthemthestoryoftheHarvardMuseumGlass
flowershandblownbytheBlaschkas–awaytopreservebotanicalspecimenstheway
youmightseestuffed(taxidermy)animalsinmuseumstoo.
Referencebook:ThePlantHuntersbyAnitaSilvey(atButterfieldLibrary!)
http://www.amazon.com/The-Plant-Hunters-Stories-Adventures/dp/0374309086
http://hmnh.harvard.edu/glass-flowersANDhttps://en.wikipedia.org/wiki/Glass_Flowers
CompositeFlowers-Sunflowers