CAU TRUC NHIEM SAC THE
1. Tim hieu ve dot bie'n cau true NST
- Khdi niem: dot bidn cdu tnic NST la nhiing bidn ddi trong cau triic
Hogt dpng cua GV
- GV neu yeu cdu:
+ Quan sat tranh hlnh vd cac dang dot bidn cdu tnic NST.
+ Hoan thanh cdc ndi dung phidu hgc tap.
- GV ke phidu hgc tap len bang de chiia bdi.
- GV cd thd tidn hanh nhu sau:
+ Ggi nhdm ghi kdt qua len bang.
+ Chidu phidu hgp tap ciia mgt so nhdm.
- GV nhan xet, danh gia va thdng bao ddp dn -> ldp theo ddi, bd sung.
Hogt dpng cua HS
- HS hoat ddng nhdm:
+ Ca nhan nghien ciiu SGK nhan biet kidn thiic.
+ Trao ddi nhdm thdng nhdt y kidn vd cac ndi dung va ghi phidu hgc tap.
- Dai dien nhdm ghi kdt qua len bang.
- Ldp theo ddi phidu hgc tap ciia nhdm khdc va trao ddi, nhan xet.
- Cdc nhdm theo doi ddp an va tu sua chiia.
Npi dung
ciia NST. Thuc chdt la su sdp xdp lai khd'i gen tren NST.
- Nguyen nhan: Tac nhan li hod, sinh hgc va rdi loan chiic nang ciia NST.
2. Cac dang dot bien ca'u triic NST
DAP AN PHIEU HOC TAP
\ . Noi
\ . dung Dang \ . dot bie'n \ . Mat doan
Lap doan
Oao doan
Chuyen doan
Khai niem
- Mat doan la dang dot bien lam mat di mot doan nao do cua NST
- Lap doan la dang dot bien lam cho mpt doan nao do cua NST lap lai mot hay nhieu lan
- La dang dot bien lam cho mot doan NST nao do dirt ra roi dao ngupc 180° va ndi lai
- La dang dot bie'n dan den sU trao ddi doan trong 1 NST hoac giira cac NST khong tuong ifng
Dac diem
- Lam giam so lupng gen tren NST - Lam mat can bang gen
- Tang chieu dai cCia NST
- Tang sd lUdng gen tren NST
- Mat can bang gen tren he gen
- Thay ddi trinh tU phan bd cac gen tren NST, thay ddi hoat dpng cOa gen
- Mpt sd gen tren NST nay dupc chuyen sang NST khac dSn den lam thay ddi nhom gen lien ket
Hau qua, vai tro
- Gay che't hoac giam SLfc sdng
VD: 6 ngudi mat doan NST 21 gay ung thU mau
- Gay dot bie'n mat' doan de loai bo gen khong mong mudn tren NST d mpt sd cay trdng
- Khong gay hau qua nghiem trpng - Tao nhieu gen mdi trong qua trinh tien hoa
- Tang hay giam cudng dp bieu hien cCia tfnh trang VD: Lua mach lap doan NST lam tang hoat tinh cua enzim amilaza, ung dung trong san xua't bia - Giam kha nang sinh san
- Tao ngudn nguyen lieu cho qua trinh tien hoa
- Co the gay chet, mat kha nang sinh san - Vai tro trong qua trinh hinh thanh lo^i mdi
- Chuyen nhom gen mong mudn tU NST cOa loai nay sang NST cua loai khac
Hogt dpng cda GV - GV yeu cdu HS tra ldi cau hdi:: Vi trf diit gay khdc nhau tren NST trong cac dot bidn cdu triic NST lieu cd gay nen nhirng hau qua khac nhau cho the dot bie'n hay khdng?
- GV neu van de: Ngay nay con ngudi da gay dot bidn cdu triic NST va sir dung dot bidn nhu the nao?
- GV sir dung thdng tin bd sung dd giang giai.
Hogt dpng cUa HS - HS van dung kidn thiic phidu hgc tap tra ldi:
Vi tri diit gay khdc nhau tren NST trong cac dot bidn cdu triic NST se gay hau qua khac nhau eho the dot bidn.
- HS van dung kidn thiic thuc td va tu lieu suu tdm de thao luan va neu dugc.
+ Con ngudi chu ddng gay dot bidn mat doan, lap doan va chuyen doan.
+ Loai bd gen xdu, tang cudng do bidu hien ciia cac gen quy.
Npi dung
4. Kiem tra danh gia
- GV yeu cdu HS tdm tdt kidn thiic ciia bai hgc - HS tra ldi cau hdi trdc nghiem
Cau 1. Ngudi ta cd the nhin thdy NST rd nhat d ki giiia ciia qua trinh phan bao la do
a) NST dan dai
c) NST nhan ddi thanh NST kep.
b) NST ddng xodn cue dai.
d) NST dan thanh hang d mat phang xfch dao cua thoi vd sdc.
Cau 2. Su bidn ddi vi trf gen tren NST la do a) Dot bidn cdu triic NST.
b) Trao ddi cheo ddng ddu giiia 2 crdmatit ciia mdt NST kep.
c) Trao ddi cheo ddng ddu giiia 2 crdmatit thudc hai NST tuong ddng.
d) Ca a, b, c.
Cau 3. Mdt det d rudi gidm la do:
a) Trao ddi cheo khdng ddu gen 16A tren NST X cua rudi cdi.
b) Trao ddi cheo khdng deu gen 16A tren NST X cua rudi due.
c) Lap doan 2 ldn tren NST X.
d) Dao doan 2 ldn tren NST X.
Cau 4. d ngudi, benh ung thu mau la do a) Cap NST 21 cd 3 chide
b) Cap NST 21 bi mdt mdt doan c) Cap NST 21 bi lap mgt doan d) Cap NST 21 khdng phan li
Cau 5. Dang dot bidn nao sau day thudng gay chdt hoac lam giam siic sdng a) Chuyen doan nhd c) Lap doan
b) Mat doan d) Dao doan 5. Dan do
- Hgc bai tra ldi cau hdi SGK.
- On kien thiic dot bidn NST (Sinh hgc 9).
- Suu tdm tu lieu vd dot bidn NST.
Bai 6
turn * 9
DOT BIEN SO LlXdNG NHIEM SAC THE