- Vai trd sinh If cua ABA.
PHIEU HOC TAP
-HS nam duoc khai nipm vd tinh hudng dpng cua thuc vat Phan bipt dugc hudng ddng ducfng va hudng dpng am.
PHIEU HOC TAP
Hudng da't
Hudng sang
Thi nghiem
Bat mpt hat dau mdi nay mam d vi trf n^m ngang.
- Dat nghieng hoac Op
chau cay mdi nay mam
- Dung mpt hpp km khoet Id nhd 5 bdn canh. chup Vcio chau cay mdi nay mam. - Dung mpt hpp kin vdi nhiing mid'ng chSn ngang dugc khoet Id so le rdi chup vao chau cay mdi nay mam.
Ket qua
- Re cong xudng dat cdn than cong Idn tren.
- Ngon udn cong va quay len tren
-Nggn cay hUdng vd phfa nguon sang.
Giai thich
- Van dpng hudng dat theo chi^u lUc hiit cDa trgng luc trai da't !a do sU phan bd dien va auxin khdng deu 6 2 mSt r l . MSt tren co lugng auxin thfch hgp cho su phan chia keo dai t^ bao la r i cong xudng dS't (Ri cd hUdrig dat duong)
- Ham lugng auxin d mat dudi cOa chdi nggn nhieu hon d mat tren.t^ bao phan chia, keo dai nen chdi nggn quay len tren (Chdi nggn c6 hudng dat am).
- Lugng auxin phan bd khong deu.
- Auxin van chuyen chO dpng vd phfa it anh sang.
- Lugng Auxin nhieu kich thfch sir keo dai cDa te bao.
- Axit Indolaxetic xam nhap vao vach td bao 232
lam ddt cac vach ngang cCia xenlulS lam cho td' bao dan dai ra.
{Hudng sang duong)
Hoqt dpng cua GV - GV cho HS quan sat hinh
23.3 SGV trang 115 va yeu
cin.
+ MO ta thi nghiem.
+ Nhan bi^t dang hudng dpng.
+ Giai thfch thi nghipm.
* Lien he: Trong thuc tiln
san xuat, ndng dan cin cd
bipn phap ky thuat nko dd cay phat uidn td't.
- GV yeu dn HS Uinh
bay thf nghipm vd tfnh hudng nude, ke't qua thf nghiem (adsbygoogle = window.adsbygoogle || []).push({});
- GV hdi; tai sao re cd hmh lugn sdng?
Hoqt ddng cua HS
- Cac nhdm sfir dung ki^n thlie d phieu hgc tap de tra Idi, giai thich.
- Yeuc^u:
+ Dang hudng dpng: tfnh hudng dat am.
+ Do su phan bd ciia Au xin.
- HS neu dugc cac bipn phap:
+ Xen ke cac loai cay. + Mat dp thfch hgp.
+ Trdng cay Uong nha kfnh.
- HS nghien cihi SGK trang 93 va quan sat hinh 23.3 ttang 93 de tta Idi.
- HS van dung kie'n thiie d hoat dpng 1 rdi ttao ddi nhdm dd tta Idi.
Yeu cin neu ducrc:
+ Rd, than mgc dung
hudng khi hat nay mim.
Npi dung
2. Hudng nudc * Thi nghiem:
- Gieo hat vao chau thung
Id hay tren ludi thep ed bOng am, tteo nghieng.
* Ke't qud
Re cd hinh lugn sdng.
Hoqt dpng cua GV
- GV giang giai bd sung
ki^n thlie.
Hoqt ddng cua HS
- GV yeu c^u:
+ Trinh bay thf nghipm vd hudng hoa cua rd.
+ Tra Idi cau hdi: so sanh su khac nhau giiia 2 chau cay ttdng trong d^t d hinh 23.4.
+ Do b6 mat chau va ludi thep cd chd thung nen rd len qua dd tim ngudn nude sau dd re van mgc diing hudng.
Ndidung
- Ca nhan nghien cilu SGK (adsbygoogle = window.adsbygoogle || []).push({});
va hmh 23.4 trang 93. - Yeu e^u neu dugc. + Cach bd tti thf nghipm. + Su phat tridn ciia rd khac nhau.
* Ket luan:
Tinh hudng nudc duong la ph^n ling sinh ttudng theo ngudn nudc.
-- Nude ddng vai ttd nhu tac nhan kfch thfch cua mdi trudng dlin ddn phan ling hudng nude.
- Trong long da't rd vuon kha xa len loi vao cac khe hd ciia d& hudng vd phfa ngudn nude dd ISy nudc. 3. Hudng hoa
* Thi nghiim:
- Dat hat nay m^m uen
ludi sat mat ditt ciia 2 chau thf nghipm.
- Chau I dat vao giOa mpt binh xdp dung phan bdn (dam, lan..).
- Chau 2: dat vao giua mpt binh xdp dung hoa ch^t dpc
Hoqt dpng cua GV
- GV yeu cin HS riit ra kit
luan vd tinh hudng hoa cua thuc vat.
- GV thdng bao them vd tinh hudng tiep xiic.
Hoqt dpng cua HS
- HS khai quat kieh thiic
Npi dung
- Chau 1: re phat ttien va
hudng ve phfa binh x6p chiia phan bdn.
- Chau 2: ri phat tridn ttanh xa cac hoa chat dpc hai.
* Ket luan:
- Re hudng tdi ngudn cha^t
cin thie't cho su sdng te" bao
(hudng hoa duong). - Re tranh xa hoa chai gay dpc hai cho te' bao (hudng hoa am).
Hoqt dpng 3: Tim hieu vai trd hifdng dpng trong ddi sdng thuc vat
Muc tieu:
- HS chi ra vai trd tfch cue ciia hudng dpng trong ddi sd'ng ciia cay.
- HS chi ra dugc bipn phap dng dung hudng ddng ciia thuc vat trong san xuSLt.
Hoqt dpng cua GV - GV neu cau hdi thao
luan: (adsbygoogle = window.adsbygoogle || []).push({});
+ Cac kidu hudng dpng cd
f nghia nhu th^ nao ddi vdi
ddi sdng thuc vat?
+ Trong san xu^t cin cd
bipn phap ki thuat nao dd cay trdng phat ttidn?
- GV nhan xet danh gia y kidn cua cae nhdm.
- GV yeu c^u HS khai quat kieh thlie.
Hoqt dpng cua HS
- HS ttao ddi nhdm.
- Van dung cac kien thlie d hoat dpng 2.
- Lien he thuc t^: lien quan tdi cac kidu hudng dpng. - Dai dipn nhdm tra Idi -> ldp nhan xet bd sung.
Npi dung
* Vai trd hudng dpng ddi
vdi ddi sdng thue vat.
Hoqt dpng cua GV
* Cung c6':
- La'y VI du dd phan bipt hudng ddng ducfng va hudng dpng am.
- Auxin anh hudng d^n van dpng hudng sang va hudng dat nhu th^ nao?
Hoqt dpng cua HS
- HS cd thd la'y vi du ling
dung v^ hudng dpng ttong
thuc ti
Npi dung
- Cac kidu hudng dpng
giiip cay thich ling vdi su thay ddi ciia di^u kien mfli ttudng de sinh trudng phat tridn.
* tfiig dung ttong san xuSft; - Tudi nude va bdn phan hgp If tao dieu kipn cho bd rd phat ttidn.
- Mat dp cay ttdng phii hgp.
- Khdng lam dung hoa chSt dpc hai vdi cay ttdng.
.
- v^ (adsbygoogle = window.adsbygoogle || []).push({});
Ke't lu$n chung: HS doc
ket luan SGK ttang 94
IV. KIEM TRA DANH GIA
- HS cd thd lam bai tap trdc nghipm sd 4 trang 94.
- Tra Idi cau hdi: Thd nao la hudng dpng? Phan bipt hudng dpng am va hudng ! dpng ducfng.
V. DAN DO
- Hgc bai tra Idi cau hdi SGK.