Thiết kế bài giảng sinh học 12 (tập 1) phần 2

ChiTdng III
^
Dl TRUYEN HOC QUAN THE

Bai 16
CAU TRUC DI TRUYEN CUA QUAN THE
I. IVIUC TIEU
1. Kie'n thiirc
- HS giai thfch dugc thd nao la mdt qudn the sinh vat cung cdc dac trung di
truydn cua qudn the.
- HS bidt each tinh tdn sd alen va tdn sd kidu gen cua qudn the.
- HS chi ra dugc xu hudng thay ddi cdu true di truydn cua qudn thd tu thu
phdn va giao phd'i gdn.
2. KT nang
Ren mdt sd ki nang:
- Phan tich, suy luan, khdi quat.
- Van dung li thuyet vao thuc tidn.
il. CHUAN B!
GV chudn bi mdt sd bai tap vd di truyen qudn the dd HS lam cung cd If
thuydt.
III. HOAT OONG DAY - HpC
1. Kiem tra
GV yeu cdu HS trinh bay kien thflc ve qudn the da hgc d ldp 9.
2. Trong tam
Khai quat hoa xu hudng thay ddi thanh phdn kieu gen cua qudn the tu thu
phdn.
179


3. Bai mdi
Hogt dpng 1

TIM Hlfiu QUAN THE
Muc tieu:
- HS ndm dugc khai niem qudn thd, vdn gen.
- HS trinh bay dugc cac dac didm dac trung cua qudn thd.
- HS bidt each tfnh tdn sd alen, kidu gen trong qudn thd.
Hogt dpng cda GV
- GV neu mdt sd vf du
va yeu cdu HS nhan bidt
qudn the sinh vat va giai
thfch.
Vf du 1: Tap hgp cdc cd
the cd chep, ca me, cd
didc cung sd'ng trong
mdt ao.
Vf du 2: Cdc ca the
chudt ddng sdng tren
ddng lua.
Vf du 3: Rittig cay thdng
Da Lat.

Hogt dpng cda HS

Npi dung
1. Dinh nghia quan the

- HS van dung kidn thflc
da hgc de nhan bidt:
Qudn the la vf du 2 va vf
du 3 vi day la tap hgp
cac ca the cung loai

cung chung sd'ng tren
mdt khu vuc nhat dinh.
- HS cd the dua them vf
du vd qudn the nhu ddi
cg Phu Thg, riing cay
dude Ca Mau...

- GV hdi: Qudn thd la - HS khai quat kidn - Qudn thd la mdt td
thflc.
chflc cua cac ca thd cung
loai, sdng trong ciing
- GV nhan xet, bd sung
mdt
khoang khdng gian
kidn thflc.
xac dinh, d vao mdt thdi
diem xac dinh va cd kha
nang sinh ra cdc thd he
con cai dd duy tri gidng
ndi.
180


Hogt dpng cda GV

Hogt dpng cda HS

Npi dung
- Qudn the la dan vi tdn
tai cua lodi.

- GV dua vdn dd:
Tai sao ndi qudn thd la
mgt td chflc cua cac ca
the cung loai?
- GV ggi y HS phan tfch
HS van dung kidn thflc
vfdu.
tra ldi.
+ Mdt long ga tam + Ldng ga chi la mdt
hoang d chg.
nhdm ca the cung loai
+ Mgt chudng thd trdng. dugc nhdt chung.
+ Chudng thd: khdng cd
mdi quan he qua lai.
+ Td chflc d qudn the tflc
la cac ca the cung loai
cd mdi quan he qua lai,
dac biet la quan he sinh
san.
2. Dac trimg di ltruyen
- GV neu cau hdi: Qudn - HS van dung kidn thflc ciia quan the
the cd nhflng dac trung sinh hgc ldp 9 tra ldi.
CO ban nao? Cho vf du.
Dac trung cua qudn the
la: Ti le gidi tfnh, thanh
phdn nhdm tudi, mat do
qudn thd.
- GV ddn ddt: Ngoai
nhflng dac trung ca ban

tren, qudn thd cdn cd dac
trung vd di truydn.
- GV yeu cdu HS:

181


Hogt dpng cda GV

Hogt ddng cda HS

Ndi dung

+ Nghien cflu SGK trang
68 muc I.
+ Neu dac trung di
truydn cua qudn thd.
- HS boat ddng ca nhan.
- HS chi ra dac didm vd
vdn gen, vd thanh phdn
kidu gen cua qudn thd.
- GV nhan xet, ddnh gid
va giang giai, giup HS
hoan thien kidn thflc vd
dac trung di truyen qudn
the.

- GV cd thd dua vf du:
+ Qudn thd 1:
0,5AA + 0,2Aa + 0,3aa

+ Qudn the 2:
0,25AA + 0,5Aa +
0,25aa
- GV ddn dat: Vdn gen
cua qudn thd khd xdc
dinh chfnh xdc nhung cd
thd nhan bidt dugc qua
tdn sd alen, thanh phdn
kidu gen.
182

- Qudn thd cd vdn gen
dac trung.
+ Vdn gen la tap hgp
cac alen cd trong qudn
thd d mdt thdi didm xac
dinh.
+ Dac didm vdn gen la
tdn sd alen va tdn sd
kieu gen.
- Mdi qudn thd cd cdu
true di truydn (thanh
phdn kidu gen) ri6ng.


Hoat ddng cda GV

Hogt ddng cda HS

Ndi dung

- GV y6u cdu HS
+ Nghien cflu SGK trang
68,69.
+ Trinh bdy each tfnh
tdn sd alen va tdn s6' ciia
kidu gen.

- GV dua bai tap van
dung dd HS tfnh tdn sd
alen va tdn sd cua loai
kidu gen vd y6u cdu HS
khai quat each tfnh
chung.

- HS boat ddng ddc lap
vdi SGK.
- HS trinh bay each tfnh
tdn sd alen cua gen vd
tdn sd ciia loai kidu gen
trong qudn thd.
- Ldp theo doi -> nhan
xdt, bd sung.
- HS khai quat cdng
thflc tinh tdn sd alen.. di
xac dinh vdn gen cua
qudn thd.

* Cach tfnh tdn sd alen
Tdn sd alen ciia mdt gen

nao dd bang ti 16 gifla sd
lugng alen dd tren tdng
sd alen cua cac loai alen
khac nhau cua gen dd
trong qudn thd tai mdt
thdi didm xac dinh.
* Cach tinh tdn sd kidu
gen
Tdn sd cua mdt loai kidu
gen nao dd dugc tfnh
183


Hogt dpng cda GV

Hogt dpng cda HS

Ndi dung

bdng ti 16 gifla sd cd the
cd kidu gen dd tr6n tdng
sd ca the trong qudn thd.
* Ciing cd: GV yeu cdu
HS lam bai tap cho bidt
dbd:
- Kidu gen AA quy dinh
long den.
- Kieu gen Aa quy dinh
long lang.
- Kieu gen aa quy dinh

ldng vang.
Trong tdng sd 1200 con
bd cua trai chan nudi cd
432con bd long den, 576
con bd ldng lang, sd cdn
lai la ldng vang
+ Tfnh tdn sd tuong dd'i
cua alen A, a.
+ Tfnh tdn sd kieu gen.

- HS tfnh dugc tdn sd
alen A la 0,6 va tdn so
alen a la 0,4.
- Tdn sd cua kidu gen
la:
AA = 0,36
Aa = 0,48
aa = 0,16

•

Hogt dpng 2
TIM Hl£u CAU TRUC DI TRUYEN CUA QUAN TH^ TI/THU PHAN VA
QUAN Tui GIAO PHOI GAN
Muc tieu:
- HS neu dugc xu hudng thay ddi thanh phdn kidu gen cua qudn the tu thu
phdn va giao phd'i can huydt.
- HS bidt van dung If thuyet dd giai thfch cdc hien tugng thuc td.
Hogt dpng cda GV
- GV yeu cdu HS:

+ Hoan thanh bang 16
SGK trang 60.
184

Hogt dpng cda HS

Npi dung
1. Qu^n the tu thu
phdn


Hogt dpng cda GV
+ Rut ra nhan xet vd xu
hudng thay ddi thanh
phdn kidu gen cua qudn
the.
- GV ggi y:
+ Tfnh tl le kidu gen di
hgp (Aa) trong tdng sd
kieu gen d tflng thd he,
+ So sanh ti 16 kidu gen
di hgp d cac thd he.

Hogt dpng cda HS

Npi dung

- HS boat ddng ddc lap.
- HS van dung quy luat
cua Menden de xdc dinh

ti 16 kidu gen ddng hgp
va di hgp d cac thd he
theo ggi y cua GV.
- HS trao ddi nhdm
thd'ng nhdt y kidn vd xu
hudng thay ddi thanh
phdn kieu gen cua qudn
thd dd la:
+ Tdn so kidu gen di hgp
giam ddn tfl 100% ->
50% ^ 25%.
+ Tdn sd kidu gen ddng
hgp tang ddn tfl 0% -»
50% ^ 75%.
- GV nhan xet, ddnh gid
va giup HS khai qudt
kidn thflc.

- Thanh phdn kieu ^en
ciia qudn thd cay tu thu
phdn qua cdc thd he thay
ddi theo hudng tang ddn
tdn sd kidu gen ddng
hgp tfl va giam ddn tdn
sd kidu gen di hgp.
185


Hogt ddng cda GV

Hogt ddng cda HS

Ndi dung
- Cdng thflc tdng quat:
+ Tdn sd kidu gen di hgp
tfl la: (1/2)"
+ Tdn sd kidu gen ddng
hgp tfl trdi = tdn sd kidu
gen ddng hgp tfl lan
1-(1/2)2
2

- GV bd sung kidn thflc:
Trong qudn thd cay tfl
thu phdn ddn ddn hi6n
tugng thoai hod, lam
giam nang sudt va chdt
lugng san phdm. Nguyen
nhan la do sd kidu gen
ddng hgp tang va gen
lan cd didu kien bidu
hien.
2. Qu^n the giao phdi
g^n

- GV hdi:
+ Thd nao la giao phdi
gdn? Cho vf du.
+ Hau qua giao phd'i gdn
Idgi?

- HS van dung kidn thflc
thuc tddd tra ldi.
- HS neu vf du vd giao
phdi gdn b loai vat nudi
trong gia dinh hoac trang
trai nhu ga, vit, bo,
trau...
- HS khai quat kidn
thflc.

- GV nhan xet, ddnh gid
va giup HS hoan thi6n
kidn thflc.
186

- Khai ni6m:
Giao phd'i gdn la hidn
tugng cac ca thd cd ciing


Hogt ddng cda GV

Hogt ddng cda HS

Npi dung
quan he huyet thd'ng
giao phd'i vdi nhau.
- Dac didm:
Giao phd'i gdn lam bidn

ddi cdu true di truyen
cua qudn thd theo hudng
tang tdn sd kidu gen
ddng hgp va giam tdn sd
kieu gen di hgp.

- GV neu vdn dd:
Nhan xet vd mflc dd da
dang di truydn trong
qudn thd tu thu phdn va
giao phdi can huyet

- HS van dung kidn thflc
trao ddi trong nhdm
thdng nhdt y kidn.
- Y6u cdu n6u dugc:
+ Trong qudn the tu thu
phdn va giao phdi can
huydt thi tl 16 kieu gen di
hgp giam.
+ Do khdng cd su ddi
mdi vd vat chdt di truyen
ddn ddn giam su di
truydn cua qudn the.

- GV hdi: Tai sao luat
hdn nhan va gia dinh lai
cdin khdng cho ngudi cd
ho hang gdn (trong vdng
3 ddi) kdt hdn vdi nhau?

- HS tra ldi dugc:
+ Ngudi cd hg hang gdn
kdt hdn, khi giao phdi
cac gen lan xdu cd ca
hdi bidu hien d trang thai
ddng hgp tfl va thd hien
kidu hinh xdu.
187


Hogt dpng cda GV

Hogt dpng cua HS
+ Con chdu dd mde di
tat, sflc sd'ng kem.

Npi dung

- HS cd the hdi: Tai sao
trong chan nudi va trdng
trgt ngudi ta vdn tidn
hanh giao phd'i can huydt
va tu thu phdn.
- Ldp trao ddi de tra ldi
thdc mde cua ban.
- HS tra ldi: Con ngudi
cd the tao dugc gidng cd
kidu gen ddng hgp bieu
hien tfnh trang tdt.
- Md rdng: GV hdi - HS trao ddi nhanh

trong chan nudi va trdng trong nhdm va tra ldi
trgt lam the nao dd giam dugc.
su thodi hod va tang do + Vdi cay trdng nen tidn
da dang di truydn cua hanh giao phan.
gidng?
+ Vdi ddng vat can lai
gidng.
4. Kiem tra danh gia
- GV yeu cdu HS nhdc lai kidn thflc ca ban cua bai.
- HS lam bai tap trdc nghiem.
Cau 1. Trong 1 qudn thd tu phd'i thi thanh phdn kieu gen cua qudn thd co
xu hudng
a) Phan hod thanh cac ddng thudn cd kidu gen khdc nhau.
b) Ngay cang phong phu, da dang kidu gen.
c) Tdn tai chu ydu d trang thai di hgp.
d) Ngay cang dn dinh vd tdn sd cdc alen.
Cau 2. Qudn the sdc cd 1500 con, trong dd sd sdc ldng nau ddng hgp tfl la
1050 con, sdc ldng nau di hgp tfl la 150 con. Bidt tfnh trang long do gen gdm 2
188


alen quy dinh, tac ddng cua chgn lgc ttr nhien la khdng dang kd. Tdn sd tuong
ddi cua mdi alen trong qudn the la
a) A = 0,75, a = 0,25
c) A = 0,3, a = 0,7
b) A = 0,6, a = 0,4
d) A = 0,36, a = 0,64
5. Dan do
- Hgc bai, tra ldi cau hdi SGK.
- Lam them bai tap trong sach bai tap sinh hgc 12 trang 49, 50.

Bai 17
CAU TRUC DI TRUYEN CUA QUAN THE
(Tiep theo)
\. IVIUC TIEU
1. Kien thurc
- HS hidu dugc thd nao la qudn the ngdu phd'i.
- HS giai thfch dugc trang thai can bang di truydn cua mdt qudn the.
- HS neu dugc cdc didu kien cdn thidt dd mdt qudn the sinh vat dat dugc
trang thai can bang di truyen ve thanh phan kidu gen dd'i vdi mdt gen nao dd.
- HS lieu dugc y nghia cua dinh luat Hacdi - Vanbec.
2. KTnang
Ren mdt sd kT nang:
- Phan tfch, suy luan giai quydt van de.
- Tfnh toan xac sudt.
- Van dung If thuye't vao thuc tidn.
II. CHUAN Bj
- Tu lieu lien quan ddn cdu true qudn thd.
- Bai tap.
189


- Cdng thflc vd cdu true di truydn cua qudn thd tu phdi.
X - la tdn sd tuong ddi cua kidu gen ddng hgp tfl trdi (AA)
y - la tdn sd tuong ddi cua kidu gen di hgp tfl (Aa)
z - la tdn sd tuang ddi cua kidu gen ddng hgp tfl lan (a a)
+ Tl 16 cac kidu gen trong qudn the la:
X AA: y Aa: zaavdix + y + z = h
+ Ndu qudn thd tu phd'i khdi ddu cd cdu true di truydn la
p: X AA: y Aa: z aa

Sdthe
hetu
phoi

1

Tl le mdi kieu gen trong quin the

a)'^

aa

AA

Aa

1

X+

z*y-(^]

L-i
2

•y

2

2

3

•y

{^'•^

x+

[^r-^

X+

^
2

z+ y -

[2]'

y-(lj.y
\-^
2

fir

4

yx+ —

[-2]'
2

III. HOAT OONG DAY - HOC
1. Kiem tra
- GV yeu cdu HS lam bai tap.
Cho bidt cdc qudn thd cd ti 16 cac kidu gen nhu sau
pi: 45% AA: 40% Aa: 15% aa
p2: 39% AA: 52% Aa: 9% aa
p3: 65% AA: 0% Aa: 35% aa
190

n

•y

z^

'2


Tinh tdn sd mdi alen trong mdi qudn thd?
Gia sfl sd lugng ca thd cua mdi qudn thd b Fl ddu la 2000 thi sd cd the b
mdi kidu gen la bao nhieu?
Dap an: A = 0,65
a = 0,35

Kidu gen

AA = 845

Aa = 910
aa = 245

2. Trpng tam
Hidu ro trang thai can bdng di truydn qudn thd.
3. Bai mdi
Mo bai: GV ddn ddt: b tidt trudc HS da dugc tim hieu cdu true di truydn
ciia qudn thd tu thu phdn va qudn thd giao phd'i gdn, tidt hgc nay nghien cihx
cdu true di truydn cua qudn thd ngdu phd'i (qudn thd giao phdi).
Hoat ddng 3
TIM HI^U CAU TRtiC DI TRUYEN CUA QUAN T H £ NGAU

PH6I

Muc tieu:
- HS ndm dugc khai ni6m qudn thd ngdu phdi.
- HS hidu dugc trang thai cdn bdng ciia qudn thd ngdu phd'i.
- Tha'y dugc y nghia cua dinh luat Hacdi - Vanbec.
- HS bidt giai bai tap vd cdu true di truydn qudn thd.
Hogt ddng cda GV

Hogt ddng cda HS

Ndi dung
1. Qu^n the ngiu phoi

- Dd hinh thanh khai ni6m
qudn thd ngdu phd'i GV n6u
cau hoi:

a) Khdi niem

+ Qudn thd ngdu phdi la
gi? Cho vfdu?
+ Qudn thd ngdu phdi khac
vdi qudn thd giao phdi gdn
nhu thd ndo?
191


Hogt dpng cda GV

- GV nhan xet, danh gia va
giup HS hoan thien kidn
thflc.

- GV yeu cau HS:
+ Nghien ciiu SGK ve qudn
the ngdu phd'i d ngudi
(trang 71).
+ Cho bidt su khac nhau
qudn the ngdu phd'i d ngudi
va d ddng vat.
192

Npi dung

Hogt dpng cda HS
- HS boat ddng ca
nhan.

- HS nghien cflu SGK
trang 71 muc I.
- HS ke't hgp kidn thflc
sinh hgc d bai trudc va
sinh hgc ldp 9 tra ldi
dugc.
+ Khdi niem qudn the
ngdu phd'i.
+ Vf du: Giao phd'i gifla
gidng ga ri vdi ga tam
hoang, lgn i Mdng Cai
vdi lgn Dai bach.
+ Qudn the ngdu phd'i
cd nhieu td hgp gen
mdi ban.
- Dai dien HS trinh
bay —> ldp nhan xet, bd
sung.

Qudn the sinh vat dugc
ggi la ngdu phd'i khi
cac ca the trong qudn
thd lua chgn ban tinh
dd giao phdi mdt each
hoan toan ngdu nhien.
•


Hogt dpng cda GV

Hogt dpng cda HS

Npi dung

HS boat ddng nhdm.
+ Ca nhan nghien cflu
SGK.
+ van dung hieu bidt
xa hdi va kidn thflc
thuc td.
+ Thao luan trong
nhdm thdng nhdt y
kidn.
- Yeu cdu neu dugc:
+ Ngdu phd'i d qudn the
ngudi dua tren nhflng
tieu chf do con ngudi
dua ra mang tfnh nhan
van.
+ Ngdu phd'i d qudn the
ddng vat mang tfnh ban
nang.
- Dai dien nhdm tra ldi
—> ldp nhan xet va bd
sung.
- GV nhan xet, ddnh gid va
ddn ddt chuydn ndi dung ve
dac didm di truydn cua
qudn the ngdu phd'i.
- GV hdi: Qudn the ngdu

phd'i cd nhiing dac didm di
truyen gi?
- GV ggi y:
+ Tai sao qudn the ngdu
phdi cd nhieu bidn di td
hgp?

b) Ddc diem di truyen
cua qudn the ngdu
phdi

193


Hogt dpng cda GV

Hogt dpng cda HS

Npi dung

+ Tai sao qudn the ngau
phd'i duy tri dugc su da
dang di truydn?
- HS boat ddng ddc
lap.
+ Nghien cflu SGK
trang 71 muc 1.
+ van dung co chd tao
bidn di td hgp nhu:
Phan li ddc lap, td hgp

ttr do cua cdc NST, su
trao ddi cheo va td hgp
tu do cua cac giao tfl
trong thu tinh.
+ Td hgp gen hay cap
gen tdt dugc phat tan
trong qudn thd va dugc
truyen cho thd h6 con
chau thdng qua ngdu
phdi.
- Dai dien HS trinh
- GV nhan xet, danh gia va bay —> ldp nhan xet.
y6u cdu HS khdi qudt kidn
thflc.
HS thao luan nhanh
trong nhdm rdi khai
quat kidn thflc vd cac
dac didm di truydn cua
qudn the ngdu phdi.

194

- Trong qudn thd ngdu
phd'i cac cd thd cd kidu
gen khdc nhau kdt ddi
vdi nhau mdt each
ngdu nhien tao n6n mdt
lugng bidn di di truyen
rdt ldn -> lam nguyen
lieu cho qua trinh tidn

boa va chgn gidng.


Hogt dpng cda GV

Hogt dpng cda HS

- GV yeu cdu HS: N6u vf
du the hien sir da dang di
truyen trong qudn thd ngdu
phdi.

- HS nghien cflu vf du
SGK trang 71 vd tdn sd
cua cac kidu gen quy
dinh nhdm mau d
ngudi.
- HS phan tfch dugc:
+ O ngudi cd 4 nhdm
mdu (A, B, AB, O).
+ Gen quy dinh nhdm
mau cd 3 alen khac
nhau va cd thd tao ra 6
loai kidu gen khac
nhau.
+ Trong quan the 1 gen
cd thd cd nhidu alen
khac nhau va sd lugng
gen d sinh vat la rat ldn
^> Qudn the ngdu phdi

cd rdt nhidu bidn di td
hgp.

- GV dua bai tap: Qudn thd
giao phdi cd thanh phdn
kidu gen 9/16 AA: 6/16
Aa: 1/16 aa.

Npi dung
- Quan the ngdu phd'i
cd thd duy tri tdn sd
cac kieu gen khac nhau
(da dang di truydn)
trong qudn thd mdt
each khdng ddi trong
nhirng didu kien nhdt
dinh.

2. Trang thai can
bang di truyen ciia
quan the
a) Khdi niem trgng
thdi cdn bdng qudn
the ngdu phdi

195


Hogt dpng cda GV
Xac dinh thanh phdn kieu

gen cac the he tidp theo.

Hogt dpng cda HS

Npi dung

- HS van dung cdng
thflc dd tfnh dugc
Tdn so alen
A = 12/16, a = 4/16
Thd he tidp sau
144/256 AA: 96/256
Aa: 16/256 aa
hay 9/16 AA: 6/16 Aa:
1/16 aa
- GV yeu cau HS: So sanh - HS nhan bidt dugc
thanh phdn kieu gen d cac thanh phdn kieu gen
cua qudn thd d thd he
thd he.
xudt phat va thd he sau
khi cd ngdu phdi la nhu
nhau.
- GV khang dinh: Qudn
the tren la qudn the can
bdng.
- GV neu cau hdi:

- HS nghien cflu SGK
The nao la trang thai can trang 72 muc 2 kdt hgp
bang qudn the?

bai tap de tra ldi.
- GV nhan xet, danh gia va
giup HS hoan thien kidn
thflc.
Mdt qudn thd dugc ggi
la dang d trang thai can
bdng di truyen khi ti le
cac kidu gen (cdn ggi
la thanh phdn kieu gen)
196


Hogt dpng cda HS

Hogt dpng cda GV

Npi dung
cua qudn the tuan theo
cdng thflc sau
p2+2pq+q2=l
+ p la tdn so alen trdi
(p2 la tdn sd kieu gen
ddng hgp trdi)
+ q la tdn so ciia alen
lan
(q2 la tdn sd kidu gen
ddng hgp lan)
+ 2pq la tdn sd kieu
gen di hgp

GV ddn ddt: Trang thai
bdng di truydn dugc
nha khoa hgc nghien
trong dd ndi bat la
Hacdi- Vanbec.

can
cac
cflu
cua

b) Dinh ludt Hacdi- GV y6u cdu HS nghien - HS khdi quat kidn Vanbec
* Ngi dung dinh luat:
cflu SGK trang 72 rdi phat thflc.
Trong
mdt qudn the ldn
bieu ndi dung dinh luat
ngdu phd'i, ndu khdng
cd cai ydu td lam thay
ddi tdn sd alen thi
thanh phdn kieu gen
cua qudn the se duy tri
khdng ddi tfl thd he nay
sang thd he khdc theo
ddng thflc
p2 + 2pq+q2=l
p2AA + 2pqAa + q2aa
=1
197

Hogt dpng cda GV

Npi dung
Hogt dpng cda HS
* Didu kien cua dinh
- GV dat vdn dd: Cd phai - HS cd the du doan:
luc nao qudn the cung d + Qudn the ludn d luat Hacdi-Vanbec.
trang thai can bdng?
trang thai can bang.
- GV giang giai:
+ Qudn thd cd the mdt
+ Trang thai can bdng can bdng.
Hacdi-Vanbec khdng chi
gidi ban cho trudng hgp
mdt gen cd 2, alen ma cd
the md rdng cho trudng
hgp mdt gen cd nhidu alen
trong qudn thd.
+ Qudn thd can bdng di
truydn cdn cd cac didu
kien.
- GV yeu cdu HS nghien
cflu SGK va phan tfch cdc
didu kien can bdng di
truyen qudn the.
- HS khdi quat kidn - Qudn thd phai cd
kfch thudc ldn.
thflc.
- Cdc ca thd trong qudn

thd giao phdi vdi nhau
mdt cdch ngdu nhien.
- Cac ca the cd kieu
gen khac nhau phai cd
sflc sdng va kha nang
sinh san nhu nhau.
- Khdng cd ddt bidn,
khdng cd CLTN.
- Qudn the phai dugc
each li vdi qudn the
khac (khdng cd du
nhap gen).

198


Hogt dpng cua GV
- GV bd sung:

Hogt dpng cda HS

Npi dung

+ Mdt qudn thd trong tu
nhien rdt khd dap dug dugc
cdc didu kien tu nhien.
+ Tdn sd alen va thanh
phdn kidu gen lien tuc bi
bidn ddi.
- GV neu vdn dd: Dinh - HS trao ddi nhdm.

* Y nghia cua dinh luat
luat Hacdi-Vanbec cd y + Dua vao bai tap dd Hacdi-Vanbec
nghia nhu thd nao?
chi ra dugc gia tri thuc
tidn va If thuydt cua
dinh luat.
+ van dung dinh luat
xac dinh thanh phdn
kidu gen cua qudn thd
va trang thai can bdng
di truydn qudn thd.
- Dai dien HS tra ldi
-^ ldp nhan xet.
- GV nhan xet va giup HS
hoan thien kidn thflc.

- Y nghia thuc tidn:
Tfl tdn sd cac cd thd cd
kidu hinh lan, cd thd
tinh dugc tdn sd cua
alen lain, alen trdi cung
nhu tdn sd cua cac loai
kidu gen trong qudn
the.
- Y nghia If luan:
+ Phan anh dugc trang
thai can bang di truyen
trong qudn the.

199

Hogt dpng cda GV

Hogt dpng cua HS

- GV bd sung kidn thflc:
Dinh luat Hacdi-Vanbec
cdn ban chd: Dd la dinh
luat nay mdi giai thfch
dugc hien tugng can bdng
thanh phdn kidu gen trong
qudn thd, ma chua giai
thfch dugc trang thai ddng
ciia qudn the do qua trinh
dot bidn va qua trinh chgn
lgc, da lam cho tdn sd
tuang dd'i cua cdc alen bi
bidn ddi.
- GV yeu cdu HS lam bai - HS van dung kidn
tap d muc V SGK trang 73. thflc vd can bdng di
truyen qudn thd dd tfnh
tan so cac alen va thanh
phdn kidu gen cua qudn
thd.
- van dung todn xdc
sudt de cap vg chdng
cd con bi b6nh bach
tang
A = 0,99, a = 0,01

AA = 0,980
Aa = 0,0198
aa = 0,001
Xdc sudt dd cd con bi
bach tang la 0,00495.
- GV nhan xet va giang
giai nhu sach GV trang 77.
200

Npi dung
+ Giai thfch dugc su
duy tri dn dinh qudn
thd qua thdi gian dai
trong tu nhien.


4. Kiem tra danh gia

- GV yeu cdu HS nhdc lai kidn thflc cua bai- HS cd the lam bai tap trdc
ngiem.
Cau 1. Dinh luat Hacdi-Vanbec phan anh didu gi?
a) Sir bidn dgng cua tdn sd cac alen trong qudn the.
b) Sir khdng dn dinh cua cac alen trong qudn the.
c) Su can bang di truyen trong qudn the giao phd'i.
d) Su bidn ddng cua tdn sd cdc kidu gen trong qudn thd.
Cau 2. Trong mdt qudn the ngdu phd'i da can bdng di truydn thi tfl ti le
kieu hinh cd the suy ra
a) Vdn gen cua qudn thd.
b) Tdn sd cua cdc alen va ti 16 cdc kidu gen.
c) Thanh phdn cac gen alen dac trung cua qudn the.

d) Tfnh dn dinh cua qudn the.
Cau 3. Trong mdt qudn the giao phd'i cd ti 16 phan bd cac kidu gen d thd he
xudt phat la: 0,64BB + 0,32Bb + 0,64b = 1, tdn sd cua alen B, b la
a) B = 0,64, b = 0,36
b)B = 0,2, b = 0,8
c)B = 0,4, b = 0,6
d)B = 0,75, b = 0,25
5. Dan do

- Hgc bai tra ldi cau hdi SGK.
- On tap kidn thflc vd quy luat di truydn Menden, phuong phdp lai d sinh
hoc 9.

201


ChiTdng IV
LTNG DUNG Dl TRUYEN HOC

Bails
CHON GIONG VAT NUOI VA CAY TRONG D^A
TREN NGUON BIEN DI TO HdP
IK'

I. MUC TIEU
1. Kien thiirc

- HS giai thfch dugc co chd phat sinh bidn di td hgp.
- HS giai thfch dugc thd nao la uu thd lai, ca sd khoa hgc cua uu thd lai,
cung nhu phuang phap tao uu thd lai.

2. KT nang

Ren mdt sd ki nang:
- Phan tfch, khdi quat.
- Van dung If thuydt vao thuc tidn.
- Khai thdc thdng tin.
II. CHUAN Bj
- Tranh hinh SGK phdng to.
- Tranh hinh mdt sd gidng cay d dia phuang, tu lieu cua HS.
- Cud'n sach: "450 gidng cay trdng mdi cho nang sudt cao" cua tdc gia
Giao su Tidn sT Dudng Hdng Dat.
- Thdng tin vd phdt hien gen lun - co sd cho tao gidng chju tham canh cao
va nang sudt cao.
+ Sfl dung cdc gen lun dd tao ra cac gidng lua mi, lua gao lun va nfla lun co
tidm nang nang sudt cao.
+ Ngudi md ra ky nguy6n sfl dung gen lun vao tao gidng la nha khoa hgc
N.Borlaug (giai thudng Nobel nam 1970). Ong da tao ra hang loat cac gidng
202


lua mi cao san bdng lai tao gifla gidng lua mi lun Morin 10 (ngudn gdc Nhai
Ban) vdi cac gidng lua mi khac.
+ Vien lua qudc td IRRI ddng vai trd chu dao trong tao gidng lua gao mdi
kidu nfla lun.
+ Gidng lua IR8 do IRRI tao ra do lai gifla gidng lua Peta ngudn gdc tfl
Inddnexia va gidng lua lun Dai Loan.
+ Gidng IRI cho nang suat cao, thfch nghi vdi nhidu vung trdng lua tren the
gidi.
+ Hdu hdt cac gidng lua trdng trong san xuat d nudc ta tfl nhflng nam 1970
de'n nay, du la gidng tao ra trong nudc hay nhap va chgn lgc tfl gidng nudc

ngoai deu dugc tao ra tren cac ngudn gen lun va nfla lun, cho nang sudt cao ban
ban cac gidng lua truyen thdng.
III. HOAT DONG DAY - HOC
1. Kiem tra
- Phat bidu ndi dung dinh luat Hacdi-Vanbec, didu kien nghiem dung va y
nghia cua dinh luat.
- Thd ndo la trang thai can bdng di truyen ciia qudn the? Cho vf du.
- HS chfla bai tap sd 2 SGK trang 73.
2. Trong tam
Uu thd lai.
3. Bai mdi
Md bai:
- GV yeu cdu HS trinh bay flng dung di truydn hgc vao ddi sd'ng va san
xudt.
- GV dua vao y kidn cua HS ddn ddt vao bai hgc.
Hogt dpng 1
TAO GIONG THUAN DUA T R 6 N NGUON BifiN DI TO HOP
Muc tieu:
- HS bidt each tao ddng thudn dua tren ngudn bidn di td hgp.
- HS thdy dugc uu nhugc diem cua phuang phdp nay.
203