III. HOAT DONG DAY HOC 1 Kiem tra
3. Bai mdi Md bai:
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 D U A 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.
Hogt dpng cua GV
- GV hdi:
+ Bidn di td hgp la gi? + Co chd phat sinh bidn di td hgp?
- GV ddn ddt HS tim hidu each tao gidng thudn dua tren ngudn bidn di td hgp.
- GV y6u cdu HS:
+ Phan tfch hinh 18.1 SGK trang 76.
+ Khai quat each tao gidng thudn dua tr6n ngudn bidn di td hgp.
Hogt dpng cda HS
- HS van dung kidn thflc
tra ldi dugc.
+ Bie'n di td hgp la su td hgp lai vat chat di truyen vdn cd cua bd me.
+ Co chd: Dua tr6n su phan li ddc lap, td hgp ngdu nhien ciia cac alen.
- HS hoat ddng nhdm. - Cd nhan nghien ciiu so dd lai, nhan bidt each tao td hgp gen mong mud'n. - Van dung quy luat di truyen Menden dd phan tfch.
- Thao luan nhdm thd'ng nha't y kie'n.
Ndi dung
* Cach tao gidng thudn
dua tren ngudn bidn di td hgp.
Hogt dpng cga GV
i - GV nhan xet, danh gia va giiip HS hoan thien kidn thflc.
* Lien he: GV yeu cdu HS trinh bay each tao gidng Ilia lun nang suat cao IR8 va each cai tidn gidng lua nay.
- GV nhan xet va sfl dung thdng tin vd gidng Ilia IR8 dd bd sung kidn thflc.
Hogt dpng cda HS - Yeu cdu neu dugc:
+ Gidng thudn mang td hgp gen ddng nhat (AABBCC).
+ Giao pha'n va tu thu pha'n (tfl P -> F4).
+ Dua ddn cdc gen mong mud'n vao cung td hgp gen dua tren su phan li ddc lap va td hgp ngdu nhien cua cac alen. - Dai dien HS trinh bay —> ldp nhan xet bd sung.
- HS boat ddng ddc lap. - HS trinh bay tr6n so dd hinh 18.2.
Npi dung
Kdt luan:
+ Tao ra cac ddng thudn chung khdc nhau.
+ Lai gidng va chgn lgc ra td hcrp gen mong mud'n.
+ Tidn hanh giao phd'i gdn hay tu thu phdn de tao ra cac gidng thudn chiing.
Hogt dpng cda GV - GV neu yeu cdu:
HS chi ra nhflng uu, nhugc diem cua each tao gidng thudn dua tren ngudn bidn di td hgp.
Hogt dpng cda HS
- GV nhan xet, danh gia
va bd sung kien thflc.
* Md rdng: GV giang giai.
- Gidng lua thudn nfla lun tuy cho nang suat cao nhung ddi hdi tham canh cao, sfl dung nhidu phan bdn, nudc tudi. - Gidng lua lun mdn cam vdi sau benh ddn de'n tang lugng thudc bao ve thuc vat gay d nhidm mdi trudng.
- HS van dung kidn thflc thuc td dd tra ldi.
- HS cd the neu dugc: + Khd duy tri gidng thudn.
+ Cac gen thudng phan li trong qua trinh giam phan.
Noi dung
* Uu didm cua cdch tao
gidng thudn dua txtn
ngudn bidn dj td hgp. - Dd tim ra td hgp gen mong mudn.
- Khdng ddi hdi kT thuat phflc tap.
* Nhugc didm:
- Mat nhidu thdi gian va cdng sflc dd danh gia tihig td hgp gen.
- Khd duy tri gidng mdt each thudn chung.
Hoat ddng 2
TAO GI6NG C 6 i/u TH£' LAI CAO
Muc tieu:
- HS hidu dugc khai niem uu thd lai.
- HS ndm dugc co sd di truyen va phuong phdp tao uu the lai. - HS n6u dugc uu, nhugc didm cua uu thd lai.
Hogt dpng cda GV - GV dua vf du di HS
hinh thanh khai niem uu thd lai.
P (Jd.thuan 1 x ?d.thuan 2 (Kilu gen (Kieu gen
AA) BB) F1 Sflc sdng hon bin bd me => ggi la uu thd lai. - GV ddn ddt: Uu thd lai dua tr6n co sd khoa hgc nao? Hogt dpng cda HS
- HS theo ddi va phan
tfch vf du => khai quat kidn thflc. - HS cd the dua vf du minh hoa. - HS nghien cflu SGK muc 2 trang 77.
- Phan tfch gia thidt sieu trdi.
+ Kieu gen dj hgp con lai cd nhieu dac diem tdt.
Npi dung
1. Khai niem
- Uu thd lai la hien tugng con lai cd nang suat, sflc chd'ng chju. kha nang sinh trudng va phat tridn cao vugt trdi so vdi cdc dang bd me. - Uu thd lai bidu hien cao nhdt d Fl sau dd giam ddn d cac thd he sau.