Tit 1, Tun 1 son: 20/8/2008 Chng I. CHUYN HA VT CHT V NNG LNG

Ngy

A. CHUYN HA VT CHT V NNG LNG THC VT BI 1: VN CHUYN CC CHT TRONG CY I. MC TIU BI HC 1. Kin thc: Qua bi ny HS phi : - M t c cu to ca r thch nghi vi chc nng hp th nc v ion khong - Trnh by c c ch hp th nc v ion khong ca r cy, phn bit c s khc nhau - nh hng ca cc tc nhn mi trng i vi qu trnh hp th nc v ion khong 2. K nng - Pht trin k nng quan st v phn tch tranh v - Rn luyn t duy phn tch- tng hp, k nng hp tc nhm v lm vic c lp 3. Thi , hnh vi - Thy c mi c th TV tn ti v pht trin lun lun cn c s hp th nc v ion khong - Thy c mi quan h thng nht gia cu to v chc nng

II. PHNG TIN GING DY - Tranh phng to hnh 1.1, 1.2, 1.3 SGK., sgk, sgv, sch tham kho III. PHNG PHP GING DY - Hi p - tm ti b phn - Quan st tranh- tm ti b phn. - Thuyt trnh - ging gii - Hot ng nhm IV.TRNG TM: - c im thch nghi hnh thi ca r TV trn cn i vi s hp th nc v cc ion khong. - C ch hp th nc v ion khong V. TIN TRNH GING DY 1. n nh lp( 1) 2. Kim tra bi c (4) Gio vin khng kim tra bi c m gii thiu khi qut chng trnh sinh hc 11. 3.Bi ging: 35 Gio vin yu cu hs khi qut v chng trnh sinh hc lp 10: Sinh hc t bo Ti sao t bo c xem l mt c th sng? HS: N1: V t bo c nhng c trng ca c th sng. GV: c trng c bn nht l kh nng trao i cht vi mi trng. Vy c th thc vt thc hin qu trnh trao i cht vi mi trng ntn? TG HOT NG CA GV HOT NG CA HS

NI DUNG CH

10 Hot ng 1

HS quan st tranh v 1 v 2 sgk

I. R L C QUAN HP T NC V ION KHANG

1. Hnh thi c r:

GV cho hs quan st hnh 1.1 v 1.2

- R chnh, r bn, lng ht, min ST ko di, nh ST. c bit min lng ht c lng ht rt R bao gm: r pht trin chnh, r bn, l N? M t cu to bn ngoi ca h r mt s TV - Min lng ht vi ht, min ST k cn? s lng lng ht nh ST. c bi rt nhiu. min lng ht c lng lng ht r pht trin GV Nhn xt v kt lun T ? c im cu to no ca r thch nghi vi chc nng ht nc?

- R cy lun pht 2. R cy pht trin v hng c nhanh b mt h

T?Mi quan h gia ngon nc trong t v s phy trin ca h r? GV b sung: S pht trin ca h r th hin kh nng thch nghi rt cao vi iu kin nc trong mi trng : nhng cy mc trong mt t c nc th r pt vi rng v su va phi. ngc li trong mt khan him nc th su v rng. Cy c lc mc su 10m ht nc ngm N? B phn no ca r thch nghi vi chc nng ht nc v mui khong? T? S lng lng ht nhiu c ngha g?

ngun nc.

th

- Cy trn cn h th nc v ion khong ch yu min lng ht

Nhn xt v kt lun GV nu hin tng thc t: Cy la sau khi cy HS kt hp vi 4 tun c h r vi tng chiu di gn 625km v hnh1.2 tr li : tng din tch b mt tip xc 285m2, ch yu l Qua lng ht. tng s lng tb lng ht. h la s lng lng ht ca 1 cy c th t 14t ci(la m en) T? TB lng ht c cu to thch nghi vi chc nng ht nc v mui khong nh th no?

T?Vi nhng loi thc vt khng c lng ht th xc gia r vi mi r cy hp th nc v ion khong bng cch no? trng, to iu kin cho qu trnh Gv gi hs tr li: trao i cht. VD cy thng, si...trn r chng c nm r bao bc. nh c nm r m cc cy hp th nc v ion khong d dng v nc v ion khong cn dc hp th qua TB r cn non(cha b suberin ho) T? Vi nhng loi cy sng trong mi trng nc

- R m su, la rng v st lin t hnh thnh nn s lng khng l ht cc lng ht b mt tip xc t gip cy hp c nhiu n -Tng din tch tip mui khong

th qu trnh hp th nc v mui khong din ra nh th no? T? Mi trng c nh hng n s tn ti v pht trin ca lng ht nh th no? ng dng ny nh th no trong trng trt?

- TB lng ht c thnh tb mng, thm cutin, c A ln.

- TB lng ht c thnh tb mng, khng thm cutin. Hot ng 2 GV chuyn : Nc v ion khong c vn chuyn vo t bo lng ht theo c ch no? GV yu cu HS nghin cu SGK v tr li cu hi: N? Dng di chuyn ca nc nh th no? GV hon thin T? C ch ny gi l g? GV Nhn xt v kt lun: T? iu kin cho c ch vn chuyn nc xy ra l g? GV Nhn xt v b sung: Cn c s chnh lch th nc gia t( mi trng dinh dng ) vi t bo lng ht: * Do qu trnh thot hi nc l ht nc ln pha trn lm gim lng nc trong t bo lng ht

* Nng cc cht tan trong t bo r cao. Yu cu HS nghin cu SGK v tr li cu hi : HS vn dng ken thc thc t tr li: N? Cc ion khong di chuyn vo t bo lng ht theo nhng c ch no? - Cy thu sinh th r t pt, khng c GV hon thin: lng ht, nc c hp th qua khp b T? iu kin xy ra qu trnh hp th ion mt ca r thn l. khong l g? - Trong mt qu u GV Nhn xt v kt lun: trng, qu acid hay thiu oxi th lng ht s tiu bin. v vy nu Treo tranh v hnh 1.3SGK hng dn HS quan trong trng trt nu st v yu cu HS cho bit: ta bn nhiu phn T? S xm nhp ca nc v cc ion khong t t qu th cy b ho vo mch g ca r bng nhng con ng no? v d b cht. nguyn nhn l do M t c th tng con ng? mt qu u trng lng ht tiu bin nc khng T? ai Caspari c vai tr g? cung cp .... GV hon thin: ai Caspari c vai tr iu chnh dng vn chuyn cc cht vo trung tr. Hot ng 3:

II C CH H TH NC V ION KHONG R CY.

1 Hp th nc ion khong t Yu cu HS nghin cu SGK v thc hn lnh HS nghin cu ni vo t bo lng III.1SGK: dung SGK tr li: N? K ra nhn yu t ngoi cnh nh hng n lng ht v qua gii thch s nh hng ca mi - Nc di chuyn t mi trng nhc trng i vi qu trnh hp th nc v ion trng trong mi khong r cy.? trng t sang mi a. Hp th n V? Bin php c s dng trong nng nghip trng u trng

hoc trong vic chm sc cy cnh to iu kin trong t bo lng cho cy ht nc v ion khong? ht. - Gi l c ch thm thu.

+ C ch: S nhp ca nc t vo t bo lng theo c ch th

* Gio dc mi trng: V? Vai tr ca nc i vi i sng thc vt? V? nhim mi trng t, nc s nh hng nh th no n r cy?

+ iu kin: C chnh lch th n gia t( hoc m - Phi c s chnh trng dinh d lch th nc gia v t bo lng h bn trong v bn ngoi mi trng.

V? Lm g bo v cy xanh?

b. Hp th ion khong + C ch:

- Theo c ch ch ng v th ng. - C ch ch chuyn ngc c Graien nng - C s chnh lch tn nng lng

- C ch th t t c nng cao vo TB lng ni c nng thp hn

nng ion khong + iu kin: gia mi trng bn ngoi v bn - C s chnh l trong t bo lng

ht Hoc cn s dng nng lng ATP ( Ch ng)

nng ion kho gia mi trng trong v bn ng bo( th ng)

HS quan st tranh v v nghin cu SGK tr li cu hi : - Nc v ion khong t t v mch g theo hai con ng:

- C s dng n lng ATP( ch ng)

2. Dng nc v ion khong i t vo mch g c

S xm nhp c nc v cc ion khong t t v + Con ng gian mch g ca r bo: i theo khng 2 con ng: gian gia cc TB v khng gian - Con ng gia gia cc b si bo: i theo kh xenlulz trong gian gia cc TB thnh TB khng gian gia b si xenlulz + Con ng t bo trong thnh TB cht: i xuyn qua t bo cht ca cc -Con ng t b TB cht:i xuyn qu bo cht ca cc

III NH H CA CC T NHN MI TRNG VI QU TR HP TH N V ION HS nghin cu KHONG R SGK v tr li cu CY.

hi

Cc nhn t ngo cnh nh p su - Cc nhn t ngoi thm thu ca d cnh nh p sut dch t, pH, thm thu, PH. thong(O2) ca nh hng n th nc v cc khong r cy

Ngoi ra r cy cng nh hng ngc li mi trng thng qua qu trnh h hp r : Gii phng CO2 v hp th O2, thi cc dch tit cha cc axit, vitamin lm ci bin mi trng t HS vn dung kin thc thc t tr li cu hi: - Vai tr: + L nguyn liu cho QH + L nguyn liu ca cc phn ng ho sinh - Mi trng t v nc nhim gy tn thng lng ht

r cy, nh hng n s ht ncv khong ca thc vt. - Tham gia bo v mi trng t v nc. - chm sc, bn phn v ti tiu hp l. V. CNG C: 1. BT4:Hy chn p n ng nht cho cc cu sau: Cu1- S ht khong th ng ca TB lng ht ph thuc vo: A. hot ng trao i cht ion B. cung cp nng lng D. hot nh thm thu B. chnh lch nng

Cu2- S ht khong ch ng ca TB lng ht ph thuc vo: A. graien nng cht tan C. trao i cht ca TB lng ATP VI. DN D: Tr li cu hi trong sgk. Lm bi tp sch bi tp. c bi tip theo. B. hiu in th mng D. tham gia ca nng

Tit 2, Tun 1 Ngy son: 26/8/2008 BI 2: VN CHUYN CC CHT TRONG CY I. MC TIU BI HC 1. Kin thc: Qua bi ny HS phi : - M t c cc dng vn chuyn cht trong cy bao gm : + Con ng vn chuyn.+ Thnh phn ca dch c vn chuyn + ng lc y dng vt cht di chuyn. 2. K nng - Pht trin k nng quan st v phn tch tranh v - Rn luyn t duy phn tch- tng hp, k nng hp tc nhm v lm vic c lp 3. Thi , hnh vi -Xy dng thc quan tm v tm hiu nhng vn thc tin trong nng nghip II. PHNG TIN GING DY -S dng tranh v v cu to ca mch g, mch ry, cc con ng ca dng mch g v mch ry, cc con ng ca dng mch g v mch ry, s lin h gia hai con ng . (Tranh v bi 2 SGK). Phiu hc tp III. PHNG PHP GING DY - Hi p - tm ti b phn- Quan st tm ti b phn.- Thuyt trnh - ging gii-Hot ng nhm IV.TRNG TM:

Cc dng vn chuyn vt cht :+ Dng mch g v Dng mch ry V. TIN TRNH GING DY 1. n nh lp( 1) 2. Kim tra bi c (4) BT1. 1-R thc vt trn cn c c im hnh thi g thch nghi vi chc nng tm ngun nc, hp th nc v ion khong? Hy phn bit c ch hp th nc vi c ch vi c ch hp th ion khong r cy? Gii thch v sao cy trn cn b ngp ng lu s cht? 3.Bi ging: 35 * t vn :(1)BT1: R cy c chc nng hp th nc v ion khong nhng nc v ion khong i vo v vn chuyn i ln thn, l, hoa , qu bng nhng con ng no?

HOT NG CA GV Hot ng 1:

HOT NG CA HS

NI DUNG CHNH

Da vo kin thc hc lp 6: cho bit - Dng mch g v dng mch * Dng mch g(dng i ln) trong cy c nhng dngvn chuyn vt ry. chuyn nc v ion khong t cht no? vo n mch g ca r ri ti dng ln theo mch gc trong lan to n l v nhng ph khc ca cy. GV:Nhn xt v kt lun * Dng mch ry( dng i xu vn chuyn cc cht hu c t t bo l chy xung cung l cc c quan s dng hoc d tr. I. DNG MCH G

Cho HS quan st cc dng mch g v dng mch ry.

1. Cu to ca mch g.

HS t chc hot ng nhm. - V pht phiu HT. Yu cu HS nghin HS nghin cu SGK v hon cu SGK v hon thin yu cu trong thin yu cu. C i din tr phiu HT li:

Mch g gm cc t bo cht l qun bo v mch ng. Cc t cng loi ni k tip vi nhau cch: u ca t bo ny gn v u ca t bo kia thnh nhng ng di.

N? Cu to ca mch g ? GV Nhn xt v kt lun T? Trong cu to ca mch g c cc l bn. Vy tc dng ca l bn l g? Gv Nhn xt v kt lun T? Mch g c nhng c im no thun li cho qu trnh vn chuyn nc v mui khong? *B sung : - Lc cn thp nh cu to ng rng (t bo cht) v thnh t bo mch g c linhin ho bn chc chu c p sut nc.Thng gia cc t bo mch g l con ng vn chuyn ngang. N? Thnh phn ca dch mch g?

* Mch g c cu to thun l s di chuyn ca dng nc v ion khong t r ln l nh c to ng rng( t bo cht) v th Gm cc t bo cht l hai loi t bo c linhin ho bn ch qun bo v mch ng. chu c p sut nc. - To li i cho dng vn chuyn ngang.

2.Thnh phn ca dch mch

T? Lm th no dng mch g vn chuyn ngc chiu trng lc t r ln cao hng chc mt nh cy su, thng, si..? Quan st hnh 2.3 em c nhn xt g? - GV cho Hs quan st H2.4 v hin tng

3. ng lc y dng mch g HS nghin cu SGK v tr li cu hi. -Nc, ion khong v cc axit c., amit, vitamin, hoocmon tng hp r.

git. Theo em nguyn nhn no lm xut hin tng git.

a. Lc y( p sut r)

GV hon thin: Ban m cy ht nhiu nc, nc c chuyn theo dng mch g ln l v thot ra ngoi. Nhng trong nhng m m t, m khng kh cao gy bo ho hi nc, nc thot ra khng bin thnh hi thot ra ngoi nh ban ngy. Do nc li thnh git ni c l kh khng, ngoi ra do cc phn t nc c lc lin kt vi nhau to sc cng b mt hnh thnh nn git nc. + Yu t th hai c tc dng nh lc ht a dng nc i ln l g? GV Nhn xt v kt lun T? Nh u dng mch g c lin tc trong cy? GV gii thch r hn v s tn ti ca lc lin kt gia cc phn t nc v vi vch mch dn qua hin tng git hnh cu u mt cc ng nh git Hot ng 2 GV yu cu HS quan st tranh H2.5 SGK phng to v tr li cu hi : N?Cu to ca mch ry? Nhn xt v kt lun :

-Nc, ion khong v cc axit ( hin tng git cc cy m hu c., amit, vitamin, l mm) hoocmon c tng hp r. - Trong cy lun c mt lc y do p sut r to nn gip y dng nc i ln.

- Nhn xt: Do nc thot ra v ng li trn u l.

T? So snh cu to ca mch ry v mch g? GV hon thin T? Phn tch s ph hp gia cu to v chc nng vn chuyn nc ca mch ry? GV Nhn xt v kt lun GV yu cu HS quan st H2.5 v 2.6 cho - Lc ht to ra do thot hi nc. bit: N? ng lc ca dng mch ry l g? Nhn xt v kt lun T? Mi lin h gia dng mch g v dng mch ry trong thn cy? GV nhn xt, b sung v hon thin kin thc. * HS quan st tranh hnh, nghin cu SGK , tho lun v tr li cu hi ca GV. - Nh c lc lin kt gia cc phn t nc v vi thnh mch g

b. Lc ht do thot hi nc

c.Lc lin kt gia cc phn nc vi nhau v vi thnh mch g.

II.DNG MCH RY.

- Gm cc t bo sng l t bo 1.Cu to : ng ry v t bo km.

- Mch g gm cc t bo cht - Gm cc t bo sng l ng r v t bo km.Cc ng ry ni ( lc cn thp) vi nhau thnh ng di t l xu r. - Mch ry gm cc t bo sng, t bo km giu ti th l ni cung cp nng lng ATP cho hot ng vn chuyn ch ng ca t bo .

- Do s chnh lch v p sut 2.Thnh phn ca dch mch thm thu gia c quan ngun ry: v c quan d tr. - Saccarz, cc axit amin, - Hai qu trnh tuy ngc hoocmn thc vt, cc hp ch chiu nhng c mi quan h hu c, mt s ion khong (nh cht ch v b sung ln nhau. K)

3. ng lc ca dng mch r

- L s chnh lch p sut thm thu gia c quan ngun(l) v quan cha (r)

V. CNG C: 1. Hy chn p n ng nht cho cc cu sau Cu 1 :Ni nc v mui khong ho tan khng i qua trc khi vo mch g ca r: a. Kh khng b. T bo biu b m e. t bo lng ht c. t bo ni b d. t bo nhu

Cu 2. Qu trnh thot hi nc ca cy s b ngng khi: a. a cy ra ngoi sng ti d. ti nc cho cy b. Bn phn cho cy c. a cy vo trong

Cu 3.Trong iu kin no sau y sc cng trng nc (T) tng: a. a cy vo trong ti b.a cy ra ngoi sng c. Ti nc cho cy d. Ti nc mn cho cy e. Bn phn VI. DN D:

- Ghi nh ni dung tm tc trong khung. SGK .

- Hc bi v tr li cu hi trong

- So snh mch g v mch ry v cc im ging nhau v khc nhau?

Tit 3, Tun 2 Ngy son: 30/8/2008 BI 3: THOT HI NC I. MC TIU BI HC 1. Kin thc: - Trnh by vai tr ca qu trnh thot hi nc i vi i sng thc vt - M t c im ca l thch nghi vi qu trnh thot hi nc qua l. - Trnh by c c ch iu tit ng m ca kh khng, v cc tc nhn nh hng n qu trnh thot hi nc 2. K nng - Pht trin k nng quan st v phn tch tranh v - Rn luyn t duy phn tch- tng hp, k nng hp tc nhm v lm vic c lp 3. Thi , hnh vi - Thy c tm quan trng ca nc i vi i sng thc vt v sinh gii ni chung - To nim hng th v say m mn hc. Gio dc thc bo v mi trng. II. PHNG TIN GING DY

- S dng Hnh 3.1, 3.2, 3.3, 3.4 SGK III. PHNG PHP GING DY - Hi p - tm ti b phn - Quan st tm ti b phn. - Thuyt trnh - ging gii -Hot ng nhm IV. TIN TRNH GING DY 1. n nh lp( 1) 2. Kim tra bi c (4) Cu 1: Chng minh cu to ca mch g thch nghi vi chc nng vn chuyn nc v cc ion khong t r ln l? Cu 2: iu no sau y phn bit gia s vn chuyn trong mch g v mch ry a. vn chuyn trong mch g l ch ng,cn trong mch ry th khng b. qu trnh thot hi nc c trong mch ry,cn trong mch g th khng c. mch ry cha nc v cc cht khong,mch g cha cht hu c d. mch g chuyn vn theo hng t di ln trn,mch ry th ngc li e. mch g chuyn ng t ngun n sc cha,mch ry th khng. 3.Bi ging: 35 * t vn :(1) Nhng nghin cu v thc vt cho thy rng ch c khong 2% lng nc hp thu vo c th thc vt dng tng hp nn cc cht hu c. Vy 98% lng nc cn li mt khi c th TV bng

qu trnh no? C quan no m nhn nhim v ny? C ch xy ra nh th no?(N2). Bi hc hm nay s tm hiu v vn ny:

HOT NG CA GV HOT NG CA HS NI DUNG CHNH - Yu cu HS nghin cu HS nghin cu SGK, nghin I. VAI TR CA QU TRN SGK kt hp vi quan st cu tranh v v tr li cu hi THOT HI NC H3.1 v tr li cu hi sau:

T? S thot hi nc l c - To ng lc ht, gip vn ngha g cho dng vn chuyn cc cht trong mch chuyn nc, cc ion khong v cc cht tan khc t r n g ? mi c quan khc. - Nhn xt v b sung: - C s khuch tn ca CO2 -L ng lc u trn ca dn GV b sung:Trong qu vo l qua kh khng. mch g gip vn chuyn n trnh thot hi nc th l lun trng thi thiu nc - To iu kin thun li cho cc ion khong v cc cht tan khc t r n mi c quan kh thng xuyn trong t bo. qu trnh quang hp ca TV din ra thun li, Gip h nhit trn mt t ca cy. to mi Do THN lm ng lc trng lin kt cc b phn c cho s ht nc lin tc t ca l cy cy, to cng cho thc vt t t vo r gi l ng lc tho. u trn. T? Cng vi qu trnh thot hi nc qua kh khng th c dng vn chuyn ca cht kh no vo l? ngha sinh hc ca kh ny? Nhn xt v KL: - Ngoi ra thot hi nc cn c ngha g khi cy b chiu sng lin tc ngoi nng? Nhn xt v kt lun

- Nh c s thot hi nc kh khng m ra cho kh CO2 khu tn vo bn trong l n c lp, ni thc hin qu trnh qu hp

- Thot hi nc c tc dng b v cc m, c quan, l cy kh b t nng, duy tr nhit th hp cho cc hot ng sinh l x ra bnh thng

.II. THOT HI NC QU

Hot ng 2: Trnh by th nghim ca Gar (1859). V Yu cu HS nghin cu Bng 3 tr li cu hi sau:(T chc hot ng nhm)

L

Hc sinh hot ng theo nhm, nghin cu SGK v tr li cc cu hi: HS c i din nhm tr li cc cu hi:

T? S gia tng khi lng ca CaCl2 sau th nghim - L l c quan m nhn chc nng thot hi nc v s thot chng t iu g? hi nc xy ra c hai mt N? Nhng s liu no cho ca l cy. php khng nh s lng - Mt trn ca hu ht cc l c kh khng c vai tr quan t kh khng hn mt di v trng trong s thot hi hm lng nc thot ra mt nc ca l cy? di cng nhiu hn so vi mt trn.

1. L l c quan thot hi n GV Nhn xt v kt lun : Hs ghi chp ni dung chnh:

T? V sao mt trn ca l - S thot hi nc xy ra theo cy on khng c kh hai con ng l: qua kh -Cu to ca l thch nghi vi khng nhng vn c s thot khng v qua cutin nng thot hi nc V: hi nc? + L c nhiu kh khng lm Gi : Mt trn khng c nhim v thot hi nc kh khng nhng vn c qu trnh thot hi nc chng + S lng kh khng mt tr t s thot hi nc xy thng t hn mt di v c ra qua cutin. tng cutin che ph hn ch mt nc. T? Da vo s liu hnh 3.3 v nhng iu va tm hiu ??? HS lng tng + S thot hi nc cn xy ra cho bit nhng cu trc qua tng cutin no tham gia vo qu trnh thot hi nc? * Qu trnh thot hi nc xy

GV b sung: Cng thot hi nc qua b mt l gim theo dy ca tng cutin ( l non tng cutin mng s thot hi nc din ra mnh, l trng thnh gim dn v l gi tng ln do s rn nt ca tng cutin. GV nhn mnh s thot hi nc ch yu xy ra qua kh khng. Yu cu HS quan st t bo kh khng H3.4 SGK. V cho bit: N? T bo kh khng hnh dng nh th no? Thnh t bo c c im g?(N2) GV b sung: T bo kh khng cha nhiu tinh bt v lc lp c nhim v lm tng p sut thm thu ca t bo kh khng n d hut - C dng hnh ht u nc vo gy ra s ng m Thnh ngoi mng v thnh kh khng. trong dy GV cho HS quan st th nghim: Dng hai ng cao su mng c mt thnh dy v mt thnh mng. Cho hai thnh dy p vo nhau. Dng nc hoc thi khng kh vo.

qua kh khng v qua tng cuti

2.Hai con ng thot hi n Qua kh khng v qua cutin.

* c im cu to t bo kh khng:

Gm 2 t bo hnh ht u qua mt vo nhau v thanh trong d hn thnh ngoi.

T? Nhn xt hin tng g xy ra? T? V sao xy ra hin tng trn? Vy khi m ti kh ny th hin tng g xy ra?

HS quan st

GV Nhn xt v kt lun : y cng chnh l c ch gy ra s m v ng ca kh khng. T? C ch ny c th trnh by nh th no? V? Hy gii thch hin tng git?

HS tr li:

* C ch ng m kh khng

- Xut hin khe h gia hai ng cao su. - Do thnh mng cng nhanh ko thnh dy cong theo lm xut hin khe h. - Hai ng cao su xp li lm khe h nh li.

Hot ng 3: Yu cu HS nghin cu SGK v tr li cu hi: Yu t no nh hng n tc THN ?

Mp trong ca thnh t bo d cn mp ngoi rt mng do t bo trng nc th mp ng dn nhanh hn lm t bo kh khng un cong v l kh m thot nc ra ngoi. Ngc li mt nc, t bo xp nhanh, m ngoi co nhanh hn lm khp kh hn ch thot hi nc

T? S ng hay m kh khng li ph thuc vo yu HS tr li t no? HS chp ni dung chnh. T? Nhng tc nhn no nh hng n qu trnh thot

III. CC TC NHN NH HNG N QU TRNH THOT HI NC.

hi nc?

GV: Nc: l nhn t iu khin s ng m kh khng.

S thot hi nc mnh hay y ph thuc vo s m ca kh khng v do hm lng nc t t bo kh khng quyt nh.

* Cc nhn t chnh nh hng HS nghin cu SGK v tr li qu trnh thot hi nc l: n nh sng: kh khng m khi cu hi ca GV: cy c chiu sng nh sng, nhit , cc ion kho - Cc ion khong nh K+ lm tng s thot hi nc. Hot ng 4 Yu cu HS nghin cu SGK v tr li cu hi: N? Th no l s cn bng nc? N? Kt qu so snh gia A v B cho thy iu g? Nhn xt v kt lun : - S m kh khng cng to th lng nc thot ra cng nhiu. -Ph thuc vo hm lng nc c trong t bo kh khng.

- C cc nhn t: Nc, nh IV. CN BNG NC V sng, nhit , cc ion khong, TI TIU HP L CHO C gi. TRNG

HS ghi chp

* Cn bng nc c tnh b so snh lng nc do r ht v v lng nc thot ra.

V? Ti sao phi ti nc cho cy trng mt cch hp l? V? Mun ti tiu hp l cho cy trng ta cn phi lm g? GV Nhn xt v kt lun

* m bo chocy sinh tr pht trin bnh thng phi t tiu hp l cho cy.

* Gio dc mi trng:

- Cn bng nc l s so snh gia lng nc do r ht vo (A) v lng nc thot ra (B) +A=B, m ca cy nc, cy pht trin bnh thng. +A>B, m ca cy tha nc, cy pht trin bnh thng +A