Cẩm nang tự ôn và luyện thi sinh học phần 2

dm nang tij On vS luy$n thi Siiih hgc - Phung Duy £)6ng COCHfeBlfeNDI TOM TAT Cty TNHH MTV DWH Khang Vigt b) Dot bie'n gen phat sinh luc ADN nhan doi va dffdc tai ban qua cd che' tff ChiTcfng I Pf|^ NOI DUNG Ve mat di truyen ngiTdi ta chia bien di hai loai la bien di khong di truyen (thiTdng bien) va bien di di truyen (bien di to hdp, dot bien) Thifcfng bie'n a) Trong qua trinh kieu gen hinh kieu hinh chiu anh hurdng cua moi tru'dng Hien tu'dng mot kieu gen co the phan iJng nhi?ng kieu gen khac nhiyng moi tru'dng khac duTdc goi la su" mem deo kieu hinh (thi/dng bien) Do mem deo cua mot kieu gen di/dc xac dinh bang so' kieu hinh CO the CO cua kieu gen d6 Sir mem deo c6 diTdc la c6 su" tuT dieu chinh cua cd the de thich nghi vdi su" thay doi cua moi triTdng b) M o i kieu gen chi c6 the dieu chinh kieu hinh cua minh pham vi nhat dinh goi la mufc phan iJng cua kieu gen MiJc phan iJng kieu gen quy djnh kieu hinh la ket qua tu"dng tac gii?a kieu gen ydi moi triTdng, moi triTdng quy dinh kieu hinh cu the cua kieu gen miJc phan iJng c) Thirdng bien khong di truyen, nhu^ng nhd no cd the c6 kha nang thich i^ng vdi nhifng bien doi cua moi tru'dng mot gidi han nhat dinh Trong san xuat ngufdi ta da van dung siT mem deo kieu hinh de tang nang suat vat nuoi, cay b^ng ki thuat san xuat hdp li ThiTdng bien c6 vai tro gian tiep cung cap nguyen lieu cho qua trinh tie'n hoa Big'n dj to h(;p ^ a) Bien di to hdp la sir to hdp lai vat cha't di truyen cua bo me qua qua trinh sinh san hiJu tinh Chung phat sinh cd che phan l i doc lap, to hdp tu" cua cdc cap NST tirdng dong (xay giam phan va thu tinh) v^ cd che hoan vi gen (xay qua trinh trao doi doan) b) Dot bic'n gen la nguyen lieu sd cap, qua giao pho'i da tao v6 so bien di to hdp la nguon nguyen lieu thi? cap cua qua trinh tien hoa va chon giong Dot bien Dot bien la nhffng bien doi vat chat di truyen (gen NST) The dot bien la ca the mang dot bien da bieu hien tren kieu hinh cua cd the 3.1 DQt bien gen a) Dot bien gen la nhffng bien doi cau true cua gen thffdng lien quan den mot cSp nucleotit (dot bien diem) nhiT: ma't, them, thay the cap nuclcotil tao cdc alen mdi, lam thay doi tan so alen va phan kieu gen cua quan the Nhffng tan so dot bien doi vdi moi gen rat tha'p (tff 10"^ - lO"*) ncn toe thay doi raft cham Vai tro chu yeu cua dot bien gen la tao nguon nguyen lieu sd cap chu yev cho qua trinh tie'n hoa va chon giong ^hSn doi cua A D N : Cac tac nhan gay dot bie'n d hoac ngoai cd the (tac nhSn l i , hoa, bazd dang hiem, virut,, ) hoac cac roi loan sinh l i , sinh hoa te j5^o da lam bie'n doi cau true cua gen dan de'n sai lech khung doc ma di truyen, hoac lam roi loan qua trinh tff nhan doi cua ADN dan tdi cap doi nham (Vi du: B U - A), lien ket sai (Vi du: Timin cung mot mach A D N lien ket vdi nhau), tao cac dang tien dot bie'n Cac dang t i l n dot bie'n c6 the dffdc cac enzim sffa chffa hoac tiep tuc nhan doi theo mau lap sai, lam phat sinh dot bie'n gen Ngoai ra, tac nhan gay dot bie'n c6 the lam cd che phien ma bi nham Ian dS'n sai sot ban phien c) Dot bie'n lam thay doi cau true cua gen d i n den thay doi cau true cua protein, lam thay doi chffc nang cua no Hau qua phu thuoc vao loai dot bie'n, vao vi tri xay dot bie'n, vao sff thay doi chffc nang cua protein, vao sff to hdp gen va dieu kien moi trffdng (gia tri thich nghi cua mot dot bie'n c6 the thay doi t&y to hdp gen va dieu kien moi trffdng) ;• d) Bieu hien cua dot bie'n gen: + Dot bie'n giao tuT qua thu tinh di vao mot hdp tff Neu la dot bien troi se dffdc bieu hien ngay, neu la dot bien Ian thi khong bieu hien (vi bi gen troi tffdng ffng la'n at) qua giao phoi dot bie'n Ian dffdc Ian rong quan the Khi gap to hdp dong hdp thi no mdi bieu hien kieu hinh + Dot bien tien phoi dffdc bieu hien tren kieu hinh cua cd the mang dot bie'n + Dot bie'n xoma, neu la dot bie'n troi se bieu hien d mot phan cd the tao nen the kham in u;'/r HHi:j'i r; + Trong qua trinh kieu gen dot bie'n hinh kieu hinh chiu sff tffdng tdc gen va chiu anh hffdng cua moi trffdng 3.2 DQt bien cau triic NST a) Dot bie'n cau true NST la nhffng bien doi cau true cua NST, thffdng lien quan den mot doan NST nao bi mat, dao, lap, hoac chuyen vi tri dan den letm hong cac gen, lam mat can bkng gen va tai cau true lai cac gen tren NST nen thffdng c6 hai cho t h i dot bie'n Tuy vay, chung cung gop phan tao nen nguyen lieu cho qua trinh tie'n hoa va dffdc ffng dung de loai bo gen xau, chuyen gen (tff NST sang NST khac hodc loai sang loai khac), xac dinh vi tri cfia gen tren NST, lam tang cffcfng hodc bat boat gen, b) Dot bien cau true NST phat sinh luc NST nhan doi, cac tac nhan gay 30t bie'n lam cho NST bi dfft, gay (doan bi dfft c6 the mat, dao, chuyen) hoac lam cho NST trao doi doan khong can (dan den lap doan) C^m nang ti; an va luygn thi Sinh hoc - Phung Duy DS'ng 3.3 Bgt bien so'lMng NST (lech bgi, da boi) * Dot bien lech boi (dl hoi) a) Dot bien lech boi la bien doi so lU'Ong xay d mot hay mot so cap NST srctng dong O sinh vat \\idng boi c6 cac dang chinh nhiT:" the khong (2n - 2), thg ot (2n - 1), the mot kep (2n - - 1), the ba (2n + 1), the ba kep (2n + 1+ 1), ihe boo (2n + 2), the bon kep (2n + + 2) Hj b) Dot bien lech boi phat sinh liic NST phan li, tac nhan dot bien lam cho mot hoac mot so NST khong phan h: + Trong giam phan: Tao giao tu* thiTa hoSc thieu mot vai NST roi qua thu tinh tao cac the lech boi: Vidu: ( n + I ) x n - > n + (theba) (n + 1) X (n + 1) -> 2n + (the bon) hoac 2n + + (the ba kep) + Trong nguyen phan: tao te bao lech boi, hinh the kham c) Dot bien lech boi lam mat can b3ng cua toan bo he gen nen cac the lech boi khong song dU'cfc, hoac giam siJc song, giam kha nang sinh san tiiy loai Tuy vay, dot bien lech boi cQng gop phan cung cap nguyen heu cho qua trinh tien hoa va dtfcfc iJng dung de xac dinh vi tri cua cac gen tren NST * Dot bien da hoi (tvC da boi, df da boi) a) Dot bien da boi la bien doi lam tang mot so Ian bo NST ddn boi (n) cua loai va Idn hdn 2n Te bao da boi c6 so liTcfng ADN tang gap boi, nen qua trinh sinh tong hdp cac chat hffu cd xay manh me Vi vay cd the da boi c6 te'bao to, cd quan sinh diTdng Idn, sinh tru'dng va phat trien khoe, chohg chiu to't Cac the da boi le hau nhiT khong c6 kha nang sinh giao tuT binh thiTdng, tao qui khong hat Dot bien da boi c6 vai tr6 rat quan trong tien hoa, gdp phan hinh loai mdi, chu ycu la cac loai thiTc vat cd hoa va ciing cd vai tro quan trong viec tao cac giong mdi b) Dot bien da boi phat sinh luc NST phan li, cac tac nhan dot bien gay roi loan qua trinh phan li cua NST lam cho NST da nhan doi, nhifng khong phan li nen so lifdng NST tang gap doi: + Trong nguyen phan cua te b^o sinh diTdng se hinh the kham tif da boi chfn, nguyen phan cua hdp tuf d nhffng Ian dau tien, khoang - te' bao se tao the tif da boi chan + Trong giam phan cua te bao sinh due se tao cac giao tu' khong giam nhiem 2n, 3n, 4n roi qua thu tinh tao cac the da boi chan hoac le Vi du: 2n X n -> 3n (the tam boi) 2n X 2n-> 4n (the tu" boi) : 3n X 2n 5n (the ngij boi) Neu cdc giao tur thuoc ciing mot loai se tao the tiJ boi, neu cac giao tijT thuoc loai khac se tao the di da boi .•'•St • • • • Cty TNHH MTV D W H Khang Vi^t VI du: Giao tuT 2n va n cua loai chuoi rilTng ket hdp vdi thu tinh tao chuoi nha tam boi (3n) Ui da boi Giao tur ni cua loai cai cu ket hdp vdi giao tuT n2 cua loai cai bap tao cd the lai (ni + nj) bat thu Gay dot bien tuT boi tao the song nhi boi (2ni + 2n2) a the di da boi hi?u thu , f, I CAU HOI T i ; LUAN | Cfiu 1: NhSng dot bien gen khong anh hufdng tdi cau true ciaa gen j • Hiidngddn Cic dot bien khong anh hU'dng tdi cafu true cua gen la: - Dot bien thay the mot cap nucleotit lam xua't hien bp ba ma hoa mot axit rain vdi bo ba ban dau - Dot bie'n diTdc enzim sufa chffa d dang tien dot bien, chiTa kip nhan oi theo mau lap sai (thong thu'dng dot bien d bp ba md dau va bo ba ket thuc ifdc suTa chffa ngay) fiu 2: Nhffng dot bie'n gen lam anh hifdng nghiem trpng de'n the dot bien? Hitdng dan - Dot bie'n mat, hoac them mot nucleotit d sat bp ba md dau - Dot bie'n thay the lam xua't hien bp ba ket thuc bat dau dich ma Cfiu 3: Nhiyng dot bien gen nhuT the nao chi lam anh hifdng den mpt axit amin? HUdng dan - Thay the' mpt cap nucleotit lam xua't hien bp ba ma hoa axit amin khac vdi bp ba md dau - Mat, them mpt nucleptit d bp ba sat bp ba ket thuc Cfiu 4: Dot bie'n gen nhif the nao dan den hau qua lam chudi polipeptit mat mpt axit amin va xua't hien axit amin mdi fV a* Hiiclngdan Mat nucleotit d ba bp ba lien tie'p Cfiu 5: Hau qua cua dot bie'n gen phu thuoc vao nhffng yeu to nao? Hiidng ddn Doi vdi cau true cua protein hau qua cua dot bie'n gen phu thuoc vao vi tr dot bie'n va loai dot bie'n Vidu: - Neu dot bien mat hoac them mpt cSp nucleotit xay d cuoi gen thi se ga) hau qua it nhat, ngifdc lai xay dot bie'n cang d phia dau cua gen thi se gay n hau qua cang nhieu ' - Neu mpt cap nucleotit bj thay the thi c6 the khong gay hau qua gi hoac ch gay bie'n doi mpt axit amin hoSc lam chuoi polipeptit bj ngan lai Ne'u mat hoac them I cap nucleotit thi tat ca cac bp ba tie'p sau deu bi thay doi Doi vdi the dot bie'n, hau qua cua dot bie'n gen phu thuoc vao si/ thay chiJc nang cua protein, vao to hdp gen va vao dieu kien moi tru'dng Cim nang tu 6n va luygn thi Sinh hpc - Phung Duy B6ng Cty TNHH MTV D W H Khang Vi$t C&u 6: T a i n h i l u dot bien nhir dot bien thay the mot cap nucleotit lai hau nhU' v6 hai d o i v d i the dot bien Hudng Hiidngddn X e t d mitc phan nhieu dot bien d i e m la trung tinh - Dot bien thay the mot cap nucleotit thiTdng chi anh hudng den mot axit amin hoac khong anh hU'dng den cau true cua protein - chpn gid'ng C f i u 14: Giffa bie'n di to hdp va dot bien gen cd d i e m nao khdc nhau? Hudng D o t b i e n d i e m xay d bo ba m d dau hay bp ba ke't thuc deu diTcfc - Dang tien dot bien c6 the dtfcJc enzim suTa chffa nen khong gay tac hai g i - M o t so dot bien geri c6 the l a m thay d d i chffc naijg cua protein theo hufdng CO Idi cho the dot bien ' - * " TiJy to hdp gen va tiiy m o i triTdng dot bien c6 hai c6 the trd c6 I d i C f i u 7: Sifphat sinh dot bien gen phu thuoc vao yeu to nao? Hitdng ddn - A D N CO nhan doi hay khong - Tac nhan gay dot bien (loai tac nhan, lieu lufdng, ci/dng do) c6 thich hdp khong truyen von cd d bo' me - Dd^i v d i sff tien hda cua loai thi dot bie'n gen cd vai trd quan trpng hdn - Dot bien gen xuat hien dot ngpt gian doan bie'n di td hdp cd the dmh hffdng trffdc b - • nhat ve cau true protein cd hoan toan|chinh xac chffa? Hudng , ddn Chffa, V I tiiy thuoc vao v i t r i ciia dot bie'n V i du: M a t hoac them mot cap nucleotit d Bp ba sat bp ba ke't thtic chi lam mat mot axit amin, thay the mot HUdng ddn T a n so dot bien gen phu thuoc: cap nucleotit l a m xuat hien ma ke't thuc d doan dau cua gen thi chudi polipeplit - Tac nhan gay dot bie'n (loai tac nhan, lieu Iffdng, cffdng do) cd the mat hau he't cac axit amin - Dac d i e m cau true cua gen (ben vffng hoSc it ben vffng) C f i u 9: L o a i dot bien nao c6 the xuat hien d d i ca the? Hudng loai khac n h a u " Theo em, cd dung khong? CSu 10: T a i dot bie'n gen c6 tan so dot bie'n thap nhffng l a i thffdng xuyen xuat hien quan the giao phoi ' =(>,«,( Hitdng ddn Yi so liTdng gen te bao rat Idn va so liTdng ca the quan the rat nhieu C f i u 11: Trong hai loai dot bie'n trpi va iSn L o a i nao cd vai tro quan hdn doi v d i tien hoa? V i sao? • ' ' HUdngdhi Dot bie'n iSn c6 vai trd quan hdn d o i v d i tie'n hda v i dot bie'n iSn i t nghiem trpng hdn va lan tran qu^n the nhd qud trinh giao phoi C f i u 12: V i dot bie'n gen cd vai tro chu ye'u cho vi$c cung cap nguyen lieu cho qua trinh tieu hda? i' C § u 16: SGK Sinh hpc 12 (trang 19) c6 ghi: "Dot bien thay the mot cap nucleotit cd the l a m thay d d i trinh tff axit amin p r o t e i n " SGK Sinh hpc 12 - Nang cao (trang 35) lai g h i : " N g u y e n nhan cua dot bie'n da bpi la lai xa giffa hai ddn D o t bien xoma va dot bie'n tien phoi HUdngddn Yi dot bie'n gen thffdng d trang thai lan, hau qua khong nghiem trpng nhff dot bie'n cau true NST va dot bien gen xuat hien phd bien hdn so v d i dot bien NST 84 N g u y e n nhan gay dot bie'n gen la cac tac nhan gay dot bie'n mdi trffdng, nguyen nhan gay bie'n di to hdp la sff to hdp lai vat chat di C f i u 15: N d i rang, dang mat hoac them mot cap nucleotit, l a m thay d d i nhieu C&u 8: T a n so' dot bien gen phu thuoc vao yeu to nao? :Jir>ii ddn Dot bien gen l a m thay ddi cau true cua gen, bie'n di to hdp thi khong e n z i m sufa chffa "' ddn D e u la bie'n di di truyen, deu cung cap nguyen lieu cho qua trinh tien hda va - tiJT, CSu 13: Dot bien g e n c o nhffng d i e m nao gidng v d i bien di to hdp? Hudng V i M i •:>•:>(!; ddn Dot bie'n thay the mot cap nucleotit khong lam dich khung dpc ma d i truyen nen khong the l a m thay ddi trinh tff cac axit amin protein L a i xa giffa hai loai khong phai la nguyen nhan gay dot bien da b p i , v i bp NST cua cd the lai chi la 2n, ne'u khong gay dot bien da bpi the -viV! Cfiu 17: Trong miic cd che'phat sinh dot bie'n gen Cd sach cho rang: 1) D o t bie'n gen k h o n g chi phu thuoc vao l o a i tac nhan, l i e u Iffdng, cffdng dp cua l o a i tac nhan gay dot b i e n ma phu tlyipc vao dac d i e m , cau true ciaa gen, • '^-^ w hiw:/' • i-n;-, • 2) Ngffdi ta gap cac dot bie'n nhff trffdng hdp xff l i A D N bang cha't acridin cd the l a m mat hoSc xen them mot cSp nucleotit tren A D N Hay phan tich cac y tren k h i ndi ve cd che dot bien t? Hudng ddn Y thff chi ndi ve tan so dot bie'n gen phu thuoc vao yeu t d nao C6n y thff thi chi n d i den chat acridin la mot tac nhan gay dot bien mat hoac them mot cSp nucleotit, khong he ndi g i ve cd che gay dot bie'n - C^m nang tij On Cty TNHH MTV D W H Khang Vi$t luygn thi Sinh hpc - Phung Duy Dfi'ng C a u 18: V e n g u y e n p h a n v a c d c h e ' p h a t s i n h d o t b i e n g e n , c a c sach c nhiTng y C S u : V i d o t bie'n ca'u t r u e N S T t h t f d n g g a y h a i nhu'ng l a i c v a i t r o nha't k i e n khac nhau: ^ i n h d d i v d i t i e n h o a v a c h p n gid'ng? - Hitdng V e n g u y e n p h a n : C o sach c h o r a n g : " N g u y e n n h a n g a y d o t b i e n g e n l a d o - ^' tac d o n g l i , h o a , h a y s i n h h p c d n g o a i c a n h h o a c r o i l o a n s i n h l i , h o a s i n h d t e D o t b i e n ca'u t r i i c N S T CO v a i t r o nha't d i n h dd^i v d i tie'n h o a l a v i : b a o " C o sach c o n du'a t h e m m o t n g u y e n n h a n ni^a l a d o cac b a z d d a n g h i e m cap - - V e c d c h e : C o sdch c h o r a n g : " C d che' p h a t s i n h d o t b i e n g e n l a : Su" k e t c a p k h o n g d u n g t r o n g n h a n d o i v a tac d p n g cua c a c tac n h a n g a y d o t b i e ' n " C o sach k h i t r i n h b a y v e c d c h e p h a t s i n h d o t b i e n g e n d a d e c a p d e n y : l o a i tac n h a n g a y d o t b i e n m a p h u thupc vao dac d i e m , c a u true cua gen d o t b i e n C a c t i e n d o t bie'n n a y t i e p tuc du'dc n h a n d o i t h e o m a u n u c l e o t i t l a p sai, cac n u c l e o t i t l a p sai n a y se l i e n k e t v d i n u c l e o t i t b d s u n g v d i n h a u v a l a m p h a t s i n h d o t bie'n t h a n h l o a i mdi V i d u : N h i e u l o a i m u o i , q u a t r i n h d a o d o a n du'dc lap d i lap l a i ^ l i f t /'sStW' IIAWJB 'J-i.'i^-' D o t b i e n ca'u t r u e N S T c u n g c v a i t r o nha't d i n h t r o n g c h p n g i d n g v i : - C h u n g c u n g c a p n g u y e n Heu c h o c h p n g i d n g - Ngu'di t a CO t h e g a y d o t bie'n m a t d o a n n h o d e l o a i k h o i N S T nhu'ng g e n - H a y p h a n t i c h v e nhiJng y k i e n t r e n v a du'a r a y k i e n c u a m i n h N g i r d i t a CO t h e g a y d o t bie'n lap d o a n , d e l a m t a n g s d l i f d n g g e n , t a n g so lutJng san p h a m c u a g e n dan Sinh hoc Idp 10) v i v a y cho r a n g tac - (.f'';-^'/'A,f>y:r!.:r [.iV\ '-"\ Ngu'di ta CO t h e g a y d o t b i e n d a o d o a n , l a m t h a y d d i v i t r i c u a g e n t r e n N S T , l a m t a n g g i a m miJc d p b o a t d p n g cua g e n n h a n s i n h h p c l a v i r u t t h i chufa c h i n h xac + D o t bie^n d a o d o a n , c h u y e n d o a n c v a i t r o q u a n t r o n g t r o n g q u a t r i n h h i n h khong m o n g muo'n - Chat a c r i d i n c the l a m m a t hoac t h e m m o t cap n u c l e o t i t t r e n A D N V i r u t k h o n g p h a i la sinh v a t ( S G K C a c d a n g d o t bie'n ca'u true N S T d e u gop p h a n t a o n e n n g u d n n g u y e n l i e u t r d n c^c N S T d a gop p h a n t a o n e n l o a i m d i - T h o n g t h i f d n g sif t h a y d o i m o t n u c l e o t i t trUdc t i e n x a y r a diidi d a n g t i e n HiCdng - cho q u a t r i n h t i e n h o a - - D o t b i e n g e n k h o n g c h i p h u thuoc vao l o a i tac n h a n , l i e u l i f d n g , c i f d n g d p cua + L a p d o a n N S T d a n de'n lap g e n , t a o d i e u k i e n c h o d o t bie'n g e n , t a o n e n >c4c a l e n m d i t r o n g q u a t r i n h t i e n h o a bo s u n g k h o n g d u n g k h i n h a n d o i B a z d d a n g h i e m k e t c a p k h o n g d u n g t h i c sach c h o r a n g , d o l a c d che' T h i f c r a b a z d d a n g h i e m l a m o t tac n h a n h o a h p c g a y d o t bie'n C d che' g a y d o t - Ngu'di ta CO t h e g a y d o t b i e n c h u y e n d o a n d e c h u y e n g e n lit N S T n a y sang N S T k h a c , tijf l o a i n a y sang l o a i k h a c bie'n c u a b a z d d a n g h i e m l a d o c h i i n g c nhiyng v i t r i H e n k e t h i d r o b i t h a y d o i C S u : V i t r i diJt g a y k h a c n h a u t r e n N S T c g a y r a nhiJng h a u q u a k h a c n h a u l a m c h o c h u n g ke't cSp k h o n g d u n g ( d a n g t i e n d o t bie'n) Sif n h a n d o i c u a cho t h e d o t bie'n k h o n g ? ADN t h e o m a u l a p sai n a y m d i l a m p h a t s i n h d o t bie'n g e n + " T r i n h b a y v e c d c h e d o t bie'n g e n t h e o thiJ tiT nhu" y d t r e n l a q u a thufa v i y thu" n o i v e t a n so d o t bie'n g e n p h u t h u p c v a o ye'u t o n a o Y thu" n o i v e a c r i d i n l a m o t tac n h a n g a y d o t b i e n Nhu'ng v a n k h o n g d a y d u !, ddn C a c tac n h a n g a y d o t b i e n d t r o n g h o a c n g o a i c d t h e (tac n h a n l i , h o a , b a z d Hitdng ddn • ' ' D o a n N S T b i dt?t g a y c d t h e x a y r a d d a u m u t giffa c i i n h h o a c m a n g t a m d p n g , l y r a nhiJng h a u q u a k h a c n h a u c h o the d o t bie'n: + Co the dua nhu sau: •^ D o a n d u t g a y d d a u m u t , c t h e b i t i e u bie'n l a m m a t m o t lu'dng v a t cha't d i i i y e n , t u y v a y luTdng v a t c h a t d i t r u y e n b i m a t i t , k h o n g g a y h a u q u a n g h i e m d a n g h i e m , v i rut, ) hoSc r o i l o a n s i n h H, s i n h h o a t r o n g t e ' b a o d a l a m bie'n d o i ' t r o n g N h U ^ g m a t d o a n d a u m u t l a m a t c a c t r i n h tiT n u c l e o t i t dijc h i e u , m a t k h i i c a u t r u e c u a g e n d a n de'n sai l e c h k h u n g d o c m a t r u y e n h o a c l a m r o i l o a n qua i;nang b a o v e v a c t h e l a m c h o N S T d i n h n h a u k h i b o a t d p n g g a y tac h a i c h o the t r i n h n h a n d o i c u a A D N d a n de'n ke't c a p b d s u n g k h o n g d u n g , h e n ke't k h o n g d u n g ( v i d u t i a tuf n g o a i c t h e l a m c h o l o a i b a z d T i m i n t r e n c d n g m o t m a c h A D N l i e n k e t v d i n h a u ) t a o r a cac d a n g t i e n d o t bie'n C a c t i e n d o t bie'n t i e p tuc , t duTdc n h a n d o i t h e o m a u l a p sai l a m p h a t s i n h d o t bie'n C f i u 19: V i d o t bie'n c a u t r u e N S T thiTdng gay h a i c h o t h e d o t bie'n Hudng + Ibien dao doan l a m thay d d i v i t r i gen tren N S T , n e n boat d p n g cua gen c the b i I t h a y d d i , h o a c k h o n g b o a t d p n g hoSc t a n g , g i a m m u t b o a t d p n g , c t h e g a y h a i + D o t bie'n ca'u t r i i c thtfcfng l a m h o n g g e n , l a m m a t c a n b a n g g e n , t a i c a u true s jjaaftt D o a n b i d u t g a y d giffa c a n h h o a c c m a n g t a m d p n g thu'dng g a y r a d o t n h i e u h a y i t c h o t h e d o t bie'n dan l a i cac g e n t r e n N S T n e n t h u t f n g g a y h a i c h o the d o t b i e n Jot bie^n iii: D o a n b i d u t g a y c the g a y r a d o t bie'n c h u y e n d o a n l a m t h a y d d i n h o m ?en l i e n k e t l a m c h o t h e d o t bie'n thu'dng g i a m k h a n a n g s i n h s a n 87 Cty TNHH MTV DVVH Khang Vigt Ca'm nang ti^ On va luyQn thi Sinh hpc - Phung Duy D6'ng HUdng ddn C a u 22: The da boi diTdc nhan bie't bang phu'dng phap nao? Hudngddn - DemsdlirdngNSTlrongtcbaodirdikinhhienvi N h i n c d the da boi bSng mat thiTdng; C d quan sinh du"9ng Idn, sinh trirdng Gen quy dinh cau true ciia protein, tiif quy dinh cac tinh trang (kieu hinh) Co the mot gen hay nhieu gen quy dinh mot tinh trang Sir bieu hien kieu hinh cua gen phu thuoc vao nhieu yeu to': a) Chtfc nang cua gen: Trong te bao chi c6 mot so gen ma hoa cac axit amin, phat trien manh, dai da so gen dong vai tro khac, khong quy dinh tinh trang nen khong bieu C a u 23: NgiTdi ta c6 the tao the tiJ boi bang each nao? HUffng ddn Bang each: hien kieu hinh b) Trang thai cua gen: Trong te bao ciing c6 nhieu gen bat boat, khong boat d6ng nen khong bieu hien kieu hinh a) Tac dpng vao luc N S T phan h nguyen phan tao te'bao sinh duTOng 4n phat trien the kham 4n l y da boi c) V i tri cua gen: Cac gen tren ciing mot N S T bieu hien k i e u hinh theo nhom li6n ket, cac gen nam tren NST khac nhau, bieu hien k i e u hinh doc lap, gen nSm b) Tac dong vao luc NST phan l i giam phan tao giao tuT 2n Cho cac giao tu^ 2n cijng loai ket hdp vdi qua thu tinh tao the tiT da boi 4n c) Tac dong vao luc NST cua hdp tu" phan l i nhiJng Ian nguyen phan dau tien tao dot bien ticn phoi, phat trien cd the tu" da boi 4n d) Cho lai khac loai tao cd the lai xa roi gay dot bien 4n tao c d the song nhi boi (the dj da boi 4n) tren NST thiTdng bieu hien khac gen nam NST g i d i tinh Gen nam nhan bieu hien khac gen nam te bao chat, d) Qua trinh sinh trifdng va phat trien cua c d the: T i i y tiTng giai doan sinh tru'dng va phat trien c6 su" bieu hien khac V i du nhieu gen quy dinh cac tinh trang sinh due phu den tudi day thi thi m d i bieu hien k i e u hinh e) Su" tu'dng tac gen: Su" bieu hien kieu hinh chiu anh hiTdng cua tiTdng \ic gen + e) Cho lai giffa cd the 6n v d i 2n, , • g) Cho the tiJboi sinh san hffu tinh hay sinh san sinh du'3ng C a u 24: C6 the tao the tam boi b^ng each nao? HUdng ddn + Tu'dng tac giffa cac gen alen: - Tu'dng tac troi, Ian hoan toan - Tu'dng tac trpi, Ian khong hoan toan - Tu'dng tac dong trpi - Tu'dng tac bd sung a) Cho ca the 3n sinh san sinh du'dng - Tu'dng tac at che - Tu'dng tac cpng gpp b) Tac dong vao luc NST phan l i giam phan tao giao tuT 2n Cho c) Cho lai hifu tinh giffa cd the tu" boi vdi cd the lu'Sng boi Cfiu 25: Cap bo me sinh mot diJa dau long mac hoi chuTng dao (cSp NST thu" 21 CO chiec) Ian sinh ihd hai cua ho c6 xuat hien hoi chilhg khong? V i sao? HUdng ddn Cd the xuaft hien nhutig vdi xac suat rat thap, v i tan so dot bien rat b6 C a u 26: Hay trinh bay khai quat ve cd chephat sinh dot bien HUdngddn Cac tac nhan gay dot bien tac dong va luc A D N nhan doi, luc N S T nhan doi, < Tu'dng tac gii?a cac gen khong alen: Bang each: giao tijT 2n thu tinh v d i giao tu" binh thu'dng tao the tiT da boi 3n lu! \ •, g) Sir tirdng tac v d i m o i tru'dng: Sir bieu hien k i e u hinh cua gen c6n chiu anh hurdng ciia m o i tru'dng: - Ciing mot k i e u gen c6 the phan iJng nhiTng k i e u hinh k h i c nhffng m o i tru'dng khac - M o i k i e u gen chi c6 the dieu chinh kieu hinh cua m i n h mot pham y i nha't djnh (muTc phan uTng viTdt qua gidi han do, gen c6 the b i dot bien va bieu hien k i e u hinh dot bien) h) Bieu hien cua dot bien gen: - D o t bien xoma: Neu la dot bien trpi se bieu hien the kham, neu la dot bien Ian thi khong bieu hien • trao doi doan, phan l i , gay r o i loan cac qua trinh do, hoSc lam bien doi cau true - D o t bien tien phoi: Du-dc bieu hien ddi ca the cua A D N cua NST TiT phat sinh dot bien - D o t bien giao Xxi: Qua thu tinh d i vao mot hdp tuf la dot bien trpi se diTdc C a u 27: Hay trinh bay chi tiet ve s\i bieu hien kicu hinh cua gen fifi bieu hien ngay, dot bien khong bieu hien va Ian tran quan the (nhd giao phoi) k h i gap to hdp dong hdp thi m d i bieu hien k i e u hinh Jki i ) Gen binh thirdng hoac gen b i dot bien diTdc d i truyen qua cac the he va dirpc bieu hien theo cac quy luat di truyen • 89 Ca'm nang tij On va luygn thi Sinh hpc - Phiing Duy Ddng Cau 28: So sanh thiTdng bien va dot bien ^ :tnK-ii QBti oh Hi^ngddn ' ' a) Gio'ng nhau: » ^ ( B) Do sur chuyen doan cija NST 91 Cty TNHH MTV DVVH Khang Vi^t Ca'm nang tij On va luygn thi Sinh hpc - Phpng Duy B6ng C ) Do cac tac nhan gay dot bien va ngoai cd the hoac roi loan sinh l i , sinh hoa te' bao D) Do N S T phan l i khong dong deu d'c^^jfi:'^ • ' • CSu 4: Dot bien la gi? ' f gu 11: Sd^gen te bao v i khong bang sd^tinh trang cua cd the: A) V i chi c6 gen cau true m d i tdng hdp protein ., B ) V i CO gen cau true bi bat boat • C ) V i CO rat nhieu gen dam nhiem cac chu'c nang khac i; ^ , "" '' ' ' > D) V i ca A , B va C A) La nhiyng bien ddi dot ngot ve cau true cua A D N B ) La nhvtng bien doi vat cha't di truyen xay d cap phan tuf va cap te bao cau 12: V i dot bien gen thifdng c6 hai, it c6 I d i , tan so thap nhiTng lai la C ) La nhiyng bien ddi dot ngot ve cau true cua NST nguon nguyen lieu chu ye'u cua qua trinh tien hoa? D) La nhi?ng bien ddi dot ngot, gian doan cua mot tinh trang CSu 5: The dot bien la gi? A) L a nhiTng ca the mang dot bien da bieu hien tren k i e u hinh cua cd the ( A) V i dot bie'n gen thiTdng iSn, dUdc Ian tran quan the, tao ngudn gen dot bie'n dif triJ rat Idn va qua giao phd^i da tao v6 so' bie'n d i td hdp B ) V i dot bie'n gen hau qua khong nghiem va xua't hien phd bie'n hdn so v d i dot bie'n NST B ) La nhi^ng bieu hien kieu hinh cua te'bao bi dot bien C ) D o t bie'n gen c6 hai c6 the trd c6 Idi t d hdp gen va tiay dieu kien C ) La ca the b i dot bien D) La trang thai cd the cua ca the bi dot bien fl moitri^ng D) V i ca l i tren CSu 6: T a n so dot bien la gi? A) La tan so xuat hien cac ca the bi dot bien quan the giao phdi f CSu 13: M o t gen k h i bj bie'n ddi ca'u true diTdc goi la: "" A) M o t gen troi dot bie'n B ) La ti le giao tuT mang dot bien tinh tren tdng so giao tuT diTdc sinh B ) M o t alen cua gen bi dot bien, tao alen m d i C ) La t i le gii?a the dot bien v d i tdng so ca the C ) M o t gen troi va lan dot bie'n D) La t i le giffa ca the mang dot bien v d i tdng so ca the , is D) M o t gen lan dot bien Cfiu 7: Dot bien xoma la loai dot bien: A) X a y d te bao sinh diTdng Cfiu 14: N o i dung nao sau day chiTa chinh xac k h i de cap den hau qua cua dang B ) X a y tai cd quan sinh dxidng dpt bie'n thay the'mot cap nucleotit? j ,, , C ) DiTdc nhan len nhd nguyen phan r d i bieu hien d mpt phan cd the A) Co the khong l a m thay ddi axit amin nao ca'u trdc cua protein D) Ca A , B va C deu dung B ) Co the chi l a m thay ddi mot axit amin chuoi polipeptit ,, C) L u o n lam thay doi mot axit amin chuoi polipeptit CSu 8: Dot bien giao tu^ la loai dot bien: A) X a y tai te bao sinh due B ) X a y qua trinh giam phan C ) B i e u hien d giao tur D) Ca A , B va C deu dung D) Co the l a m cho chuoi polipeptit ngan l a i CSu 15: Dot bie'n nao sau day lam thay ddi ca'u true protein nhieu nha't? B ) Ma't cap nucleotit A) Dot bien xuaft hien vao giai doan dau cua sU phat trien phoi B ) D o t bien xuat hien d giai doan phoi phan hoa te' bao • -i , n-'od'*^ i;;;; ') D) Ma't cap nucleotit ci v i tri cudi gen Cau 16: K h i noi ve dot bie'n NST dieu nao sau day la sai? A) La nhu*ng bien ddi ve ca'u true NST, ve so lufdng cua mot cap N S T hoac tat C&u 10: N p i dung nao sau day sai? cacaccSpNST A) Dot bien gen k h i phat sinh diTdc k i e u hinh k i e u hinh ^'^ By Dot bie'n N S T la nhffng bie'n ddi ve cd scl vat chat di truyen d cap te'bao B ) Dot bien gen c6 vai tro cung cap nguyen heu chu ye'u cho qua trinh tien hoa C ) D o t bie'n N S T la nhffng bie'n ddi gay cic dang: Ma't doan, dao doan, ISp C ) Dot bien gen c6 the c6 Idi, c6 hai hay trung tinh D) Dot bie'n gen la loai dot bien xay d cap phan tuT ,\;':, a-i • C ) M a t cap nucleotit d v i tri dau gen C ) Dot bien xua't hien nhi?ng Ian nguyen phan dau tien cua hdp tur D) Dot bien xua't hien qua trinh phat then cua phoi , A) Ma't cap nucleotit C a u 9: Dot bien tien phoi la gi? ^ I doan, lech b o i , da boi D) Khong c6 cau nao sai oiii;.' > C a m n a n g lif o n va l u y Q n t h i S i n h h g c - P h u n g Duy Bdng Cty T N H H C a u : K h i noi ve nguyen nhan gay dot bien NST d i c u nao sau day la chua chinh xac? , ; ^sj^ dSy khong dung? ' B ) L a m thay d o i hinh dang, kich thu'dc cua NST ' ' • C) L a m thay d o i nhom gen Hen ke't cua NST D ) Tat ca A , B va C C) C d che gay dot bien NST la cac tac nhan gay dot bien l a m r o i loan qua ' , CSu : H a u qua cua dot bien lap doan doi v d i ca'u true N S T la: , D ) Khong CO cau nao sai C a u : K h i noi den dot bien mat doan, dieu nao sau day khong dung? A ) Doan b i mat c6 the d dau mut, giffa canh hoSc mang tam dong > i A ) L a m cho cac gen tren NST xa hdn ; B ) L a m thay d o i hinh dang kich thiTdc NST i., ^ C) Khong l a m thay d o i nhom lien ke't gen tren NST B ) X a y qua trinh N S T nhan d o i D ) Tat ca A, B va C CSu : H a u qua cua dot bie'n dao doan d o i v d i cau true N S T la: CSu : Phat bieu nao sau day sai? A) Dot bien lap doan lam tang them vat chat di truyen, lam bien doi hinh thai NST B ) L a p doan l a m tang hay giam cu'dng bieu hien cua tinh trang l\ A ) L a m cho cac gen tren N S T xa hdn iI B ) L a m cho cac gen tren N S T gan hdn ' - C) Khong l a m thay d o i nhom lien ke't gen tren NST • - D ) Tat ca A, B va C C ) H a u qua cua lap doan l a m thay d o i nhom gen l i e n ke't CSu : H a u qua cua dot bie'n chuyen doan doi v d i cau true N S T la: ; i; A ) L a m cho cac gen tren N S T xa hdn, gan hdn cap N S T ttfdng dong kep B ) L a m thay doi hinh dang, kich thifdc NST CSu : Cau nao sau day khong dung? C ) L a m thay d o i nhom lien ke't gen tren NST A ) Trong cac dang dot bie'n cau true NST, dao doan la dang dtfdc gap bien hdn ca D ) Tat ca A , B va C B ) Trong cdc the lech boi, dang 2n + va 2n - gap bie'n hdn ca C u : N o i dung nao sau day sai? C ) PhiTdng phap bie'n nhat hien di/dc uTng dung de gay dot bie'n da A ) L i e n quan de'n nhieu NST khac ciing dut doan, sau trao d o i doan ;r B ) Cac doan trao d o i c6 the xay mot cap N S T tifdng dong nhUhg phai khac chiJc nang, nhu-giQ-a NST X va NST Y C) NST duflt mot doan, chuyen den vi tri mdi cung mot NST hoSc NST khac i-.nr.:,; " r i dUWc n o i l a i D ) Tat ca A , B va C deu diing Cflu 2 : K h i de cap den dot bie'n chuyen doan N S T dieu nao sau day dung? '' '• A ) Dao doan xay k h i mot doan ben NST b i dut, doan quay ngiTdc boi the la dung consixin vdi nong dp 0,1 - 0,2% dut v d i • A ) L a m cho cac gen tren NST gan hdn trinh tu" nhan d o i cua NST , C a u : H a u qua ciia dot bie'n mat doan doi v d i cau true N S T la: B ) Ccf che' gay dot bie'n NST la cac tac nhan gay dot bien l a m r o i loan qua D ) C d che' phat sinh lap doan la trao doi doan khong can gii?a cromatit ; v.^' D ) Khong cau nao sai ca A ) Ccf che'gay dot bien NST la cac tac nhan gay dot bien l a m diJt gay NST D ) Doan b i mat, ne'u khong chiJa tam dong se b i thoai hoa • C) D o N S T khong phan l i qua trinh phan bao hoc nhif B U , acridin tac dong vao luc A D N nhan d o i C ) X a y qua trinh nguyen phan hoac giam phan Vigt B ) D o r o i loan cd che phan U cua NST d k i sau phan bao C) Nguyen nhan gay dot bien NST la cac bazcf dang hiem, cac chat hoa trinh phan l i cua N S T phan bao Khang A ) D o thoi vo sac khong hmh hoac b i pha huy B ) Nguyen nhan gay dot bien NST la cac roi loan sinh li- sinh hoa te bao C a u 18: K h i noi ve c d che gay dot bien NST cau nao sau day khong dung? DVVH C a u : K h i di cap de'n nguyen nhan ve dot bie'n so Itfdng NST, cau nao sau A ) Nguyen nhan gay dot bien NST la cac tac nhan l i , hoa ngoai canh D ) Cau C chtfa chinh xac MTV B ) Doan N S T bj dao phai n l m d dau hay giiJa canh cua N S T va khong mang f tam dong C) Dao doan i t anh hu'dng de'n siJc song cua sinh vat khong l a m ma't vat chat d i truyen D ) Ddo doan l a m thay d o i trat tU s^p xep cac gen tren N S T nhiTng khong l a m o thay doi nhom gen l i e n ke't D ) Tat ca A , B va C deu dung '• 95 Ca'm nang l\f On va luy$n thi Sinh hpc - Phiing Duy Bfl'ng Cty TIMHH MTV DWH Khang Vigt Cau 29: Cac the dot bien nao sau day d ngUdi la hau qua cua dot bien l$ch bpi dang2n+ 1? A) Hoi chuTng TdcncJ, ClaiphentcJ, Dao ' r Ba cap nucleotit ma't di phai la: cap G - X va cap A - T Do so nucleotit moi loai cua gen dot bie'n la: ^ 'V*' A = T = 1 - = 116 nucleotit G = X = 466 - = 464 nucleotit 'T Loai 3: Xac djnh tan so' dot bie'n gen ; PhiMng phap giai: f; - Tim so' giao tiJf mang dot bien gen - Tim tdng so giao tuf difde sinh Tiir d6 suy tan so dot bie'n gen Widu: Theo doi 100000 tre em sinh d mot nha ho sinh, ngiTcfi ta tha'y c6 10 em '^n bam sinh, c6 em c6 bd hoac me liin, cac em lai bd me deu bmh tbuTcfng (sinh mot dong ho khong c6 ngi/cfi lun) Tinh tan so dot bie'n gen HUdng ddn - Bd me tbiTcfng ma liin cbitng to la dot bie'n trpi fl - Trir trU"6ng hdp da c6 bd hoac me liln, triTdng hdp liin la c6 dot ^iS'n lun phat sinh giao tuT cua bd hoac me - ' dm nang tij On va luygn thi Sinh hgc - Phung Duy oa'ng Cty TNHH MTV DWH Khang Vigt b) X a c dinh so loai giao tu" c6 kha nang song va phan gen cua m o i loaj Sadolail: giao tur diTOc h m h tu" bo va me (Cd the 4n chi c6 giao tit 2n m d i c6 kha nang song C d the 3n thi giao tu" n va 2n deu c6 kha nang song) c) Cho cac loai giao tuT cua bo', me ket hdp v d i (lap bang) TCf suy P X"X" X^Y G(P) x"x^ox^Y ^ F, IX^X^Y : I X ^ X ^ X " : X ^ : Y ,v -^ ' , (Con trai X^X^Y CO bieu hien benh m i l mau) u" phan l i k i e u gen va k i e u hinh Vidu 2: M o t cap v d chong sinh d^dc ngu'di con: Lr^a/?M/ia/.-Bie't ke't qua l a i , t i m cong thi?c l a i Dtfa thiJ nhat c6 kieu hinh binh thiTdng, difa thu" hai c6 bieu hien benh Dao Phu"dng phap giai loai toan nhu" sau: Cap v d chong c6 nhCng ban khoan: a) X a c dinh so k i e u hinh lap chiem t i le bao nhieu ( V i du 6) HoSc t i m xem T a i l a i sinh diJa thu" hai nhu* vay? D o v d hay chong? CO k i e u hinh nao chi chiem mot phan tdng so cac phan k i e u hinh dtfdc sinh N e u sinh ni^a thi diJa tre sinh c6 bieu hien bdnh Dao hay khong? (xem v i du 3) Ngu'di b i benh Dao c6 kha nang sinh hay khong? N e u c6 thi hp se b) Xac dinh nhi?ng k i e u gen nao sinh t i le giao tu'tren nhiT the nao? Hay giai dap ban khoan noi tren c) Tu" suy cac sd lai va giai tijfng sd l a i Hudngddn Loai 6: G i a i thich cac hien ttfdng dot bien ' DiJa binh thudng la sif tai to hdp gii?a triJng b i n h thifdng (n) v d i tinh Vi du 1: Do dot bien nen- c6 nhiJng cd the c6 NST g i d i tinh la X O hoSc X X Y trung binh thtfdng (n) ^ Cung dot bien, c6 nguTdi c6 gen Ian nam tren N S T g i d i tinh X va bieu hien DiJa khong binh thiTdng (bieu hien benh Dao) la qua trinh giam benh m u mau M o t cap v d chong, ca c6 k i e u hinh binh thtfdng hp sinh mot dtfa gai phan phat sinh giao tuT cap NST thur 21 khong phan l i nen da tao loai giao tuf: M o t loai c6 ca chiec cua cap 21 (n + 1) mot loai X O , bieu hien benh m i i mau khong chuTa chiec nao cua Hay giai thich hien tu'dng cap 21 (n - 1) K h i thu tinh, giao tuf thifa chiec cua cSp 21 ket hdp giao tuf binh M o t phu nff bieu hien benh mu mau, ket hon v d i mot ngiTdi c6 k i e u hinh thirdng tao hdp tuf cap 21 cd chiec phat trien benh Dao Su" g i a m phan khong binh thu'dng c6 the tijf te bao sinh tinh triing hay te bao binh thu^dng Hp sinh drfdc mot dtfa trai Neu diJa trai c6 N S T gidi tinh la X X Y , khong bieu hien benh m i i m ^ u hoac c6 bieu hien m i l mau thi giai sinh triJng V i vay nguyen nhan gay benh c6 the v d ho^c chong thich sao? T u y nhien, nhiTng nghien ciJu tren the gidi cho bie't t i le b i benh Dao tang len ' Hudngddn G i a i thich hien tu'dng: Quy urdc X'^: K h o n g bieu hien benh m i i mau X^• Bieu hien benh m i i mau Con gai X O nhan X " tCf me va O turbo Bo me CO k i e u hinh binh thiTcfng Sif giam phan te bao sinh due cua b d c6 hien tu'dng dot bien the d i b p i Sddolai: P : G(P) F, X^X"xX^Y :X^rxX^Y,0 : I X ^ X ^ Y : I X ^ ^ Y : I X ^ O : I X ' O (con gai bieu hien benh) Con trai X X Y cd va khong bieu hien bpnh m i i mau Co the giai thich bang sd sau: Saddlail: ^ P : X^X^xX^Y G(P) : X" x X ^ Y , F, : I X ^ X ' - Y : IX^O (Con trai X ' ^ X ' Y khong bieu hien benh m i i mau) 114 X , Cling f vdfi tuoi ngu'di me sif giam phan d ngtfcli phu nif l 3X"X" ( ? hoang dai): 3X"Y {S hoang dai): I X ^ X " ( $ dot bien) Dod6liledF2la:3dirc:4cai dot bidn : hoang dai Hb'.Hb' : IHb'Hb^ 2Hb^HbMHbW x : ^ X ^ X " : ^ X " X " : ^ X " Y (X'^Ybjchet) Tinh binh thu'dng Hb*Hb' xac sua't 25% theo sd sau: ^^u.|J,,^ : X"Y G(F,):X",Y G(F,):X",Y nhan giao tuf Hb^ hoac cua me hoac cua bd : Hb^Hb' a) F , F2 Do kieu gen cua P: Hb^Hb'xHb^Hb' , , B d m e : H b ' H b ' x Hb^Hb* ' Fi xay phep lai: Ong noi binh thu'dng c6 kieu gen H b ' H b ' truyen cho b d gen H b ' Ong ngoai G V i i CO ti le difc : cai dot bie^n : hoang dai :''p'Sir^^ • cam nang tij on va Iuy6n Ihi Sinh hpc - Phting Duy Pgng Cty T N H H M T V D W H Khang Vigt Vi du 5: tarn dau (2n = 28) gidi tinh cai difdc quy dinh bdi cap NST X Y , gidi tinh diTc dtfcJc quy dinh bdi cap NST X X Gen quy dinh mau sac trijrng nam tren cap NST so 10 M e n A xac dinh trtfng mau trang, alen a quy dinh tru-ng mau xam den Tit noi tam triJng trang va triJng xam den, ngu'di' ta da tao diTOc noi tam ma lai vdi se cho ^ so triJng mau xam den, nd toan tam cai va - Do'i vdi noi tnJng mau x i m den X'' d6t bien a) ^ ^ ^ i.\ so triJng c6n lai cd mau trang nd toan llm d\ic (Ken tam dufc cd nang sua't td tang trung binh 30% so vdi ken tam cai vi vay ngiTdi ta chi suf dung ken tam di/c de siin xua't td) Hay giai thich ngiTdi ta da tao dong tam nhu" the nao? HMngddn + Y chuyfin doan Y TCf loai ca the se cho triJng mang NST X ' va NST so 10 khong mang en a ( - X") 2^ dot b) c5 bie'n X" ;—'-r~, a X chuytn doan - > —=• ^ ^ TuT loai ca the se cho tinh trung mang X" va NST so' 10 khong mang en a (-X") va Hal noi tam ma cho lai vdi cho: - so trtog mau trang nd toan tam du-c va - lai mau xam den, nd toan tam cai Chtfng td tinh trang mau sac triJng lien ke't vdi gidi tinh => gen xac dinh nd nam tren NST gidi tinh c) Cho tnJng (-X") ket hdp vdi tinh trilng (-X") se tao hdp tu^ = — X" iii tren diTc cd NST so 10 khong mang gen quy djnh mau s^c ma cd T X mang gen a quy dinh mau xam den XA A P3 Cho lai noi tam cai trtfng trang dot bien vdi noi tam di/c trtfug + T i le : la ket qua cua phep lai phan tich P : $ X^Y cJX" X" X G(P) : - X ^ , - Y X" + V i gen quy dinh mau sac trtfng n^m tren NST thtf 10 Do vay, de cd diTdc noi tam tren, ta phai gay dot bien chuyen doan NST mang gen xac dinh mau sac tru-ng tiT NST thu" 10 sang NST gidi tinh X, nhif sau: Doi vdi noi tam tri^ng trang: N O — — gay d6l bien ' chuyd'n doan ^ Y 2^ ^ _ 2^ ^ A Y Tam cai dot bien se cho triJng mang NST Y va NST so 10 khong mang gen A ( - Y ) A b) A X g ay doi bia'ii ^ _ = = gay noi Dieii ^ ^ ^ c h u y e n doan _ X Tam difc dot bien se cho tinh trung mang NST X^ va NST so 10 khong mang gen A (-X'*') c) Cho tnJng ( - Y ) ket hdp vdi tinh trung ( - X'^) se tao hdp t^ = 18 ch hien tu-dng tren 1^ HUdngddn • O loai nay, nhieu phan tren mot NST cd cMc nang tu-dng tiT nhU" tam dong phdng xa lam dut NST nhieu doan nhd, cac doan nho cd chiJa chi^c 'ng nhu- tam dong trd NST doc lap, lam cho so Itfcfng NST te bao Ig ma khong lam thay doi ham lu-dng A D N te bao J TAP VAN DVNG Hay van dung cac phu-dng phap giai cua tijfng loai toan da de cap de'n d tren, i ciic bai tap sau: X^ Y phat trien cai cd chtfa cap NST so 10 khong mang gen quy dinh m^u sac, ma cd NST X mang gen A quy dinh mau trtfug trang den dot bien se cho — so' triJng mau xam den nd toan tam cai va — so' 2 g mau xam den nd toan tam difc nhu" sd lai d tren Vidu6: Mot loai cay cd bo NST Itfdng boi 2n = 24 Ng^di ta phdng xa hat cua loai y phoi mam cac NST te bao chtfa ti/ nhan doi Quan sat diTdi kinh hien vi cac phien trung k i cua Ian phan bao dau tien cua bao phoi mam ngu-di ta thay so lifdng NST Idn hdn 24, nhien ham Itfdng p N te bao khong doi so vdi te bao chiJa bo NST lu-dng boi 2n Hay giai i 1: Mot gen chi huy tong hdp chuoi pohpeptit gom 498 axit amin cd — = - G bie't dot bie'n xay khong lam thay doi so nucleotit cua gen Mot dot bie'n xay lam cho gen sau dot bien cd ti le — = 66,48% Dot G In thuoc dang nao cua dot bie'n gen? 119 d m nang tij 6n Cty TNHH MTV D W H Khang V i g t ^ luygn thi Sinh hpc - Phung Duy D6ng M o t dot bien xay l a m cho gen sau dot bien c6 t i Ic — = 66,85% • Dpt G bien noi tren da l a m cho cau true cua gen b i thay ddi nhU' the" nao, thupc dang nao cua dot bien gen? D o t bien xay gen B l a m ma't mot axit amin chtfng to dot bien dang mat cap nucleotit ke tiep chiJa trpn bp ba ma hoa - A x i t amin thu" hai iJng v d i bp ba ma hoa thii: ba tren mach ma go'c V a y dot bien l a m mat bp ba ma hoa d v i t r i thiir ba cua gen Hudng dan Gen' ban dau chi tong hdp chuoi polipeptit gom 498 axit amin, chiJng to gen CO so'nucleotit la: [(498 X 3) + (nucleotit cua bo ba m d dau) + (nucleotit cua bo ba k e t thijc] X = 3000 So'nucleotit tufng loai cija gen: A + G = 0 : = 1500 Ta CO he phu"cfng trinh: HUdng ddn - ' " ''^^ A_2 B a i 3: Gen A quy dinh mat mau do, alen dot bien a quy dinh mau mat hong K h i gen n o i tren ciJng tai ban Ian thi m o i triTdng noi bao cung cap cho gen mat nhieu hPn gen quy dinh mat mau hong 90 nucleotit tiT D o t bien gen da cho t i le: ^='^=66,61% g i a m xuong 66,48% v i so It/dng nucleotit gen khong thay ddi nen so loai nucleotit loai A giam cung bang so' nucleotit loai G tang Gpi X la so nucleotit loai A giam d i dot bien, ta c6 phiTdng trinh: Trong gen dot bien c6 the xay cac tru'cfng hdp sau: ; Giai phufdng trinh ta c6 x = + Ba cap nam trpn v e n bp ba ma hoa + Ba cap thupc hai bp ba ke tiep tren mach ma goc N e u xet thiJ tif tijr trai sang phai thi c6 the xay hai triTdng hdp: - H a i nucleotit cua bp ba ben trai nucleotit cua bp ba ben phai - M o t nucleotit d bp ba ben trai, nucleotit cua bp ba ben phai b) Ma't cap nucleotit nam bp ba ke" tiep nhau: dan den mat axit amin, xuat hien axit amin m d i c) Ma't cap nucleotit nam r a i rac d cac v i t r i khac gen dan den Al^ = ^ = 66,48% = 0,6648 G +x 900 + x dich khung doc ma d i truyen tai nhieu v i t r i khac nhau, gay hau qua tai hai hdn '' cdc tru'dng hdp tren B a i 4: Gen A ma hoa 498 axit amin M o t dot bien xay l a m cho gen mat Nhir vay dot bien da l a m thay ddi cap A - T bang cap G - X mot doan g o m nuclcolit K h i tdng hdp A R N thong tin tiJT gen da b i dot bien m o i Dot bien dang thay the cap nucleotit bang cap nucleotit khac triTdng noi bao da cung ca'p 7485 ribonucleotit tuf Gen dot bie'n da ma bao D o t bien l a m cho t i le — tiT 66,67% tang len 66,85% Chi?ng to so G nucleotit loai A tang Tat nhien so nucleotit A tang len bang so nucleotit G giam nhieu Ian? Hiidng ddn - oK ft X ; • S d b p ba cua gen A : 498 + = 500 nu; Suy so nucleotit cua gen bang: 500 x x = 3000 nucleotit di, nen ta c6 phu'dng trinh: 600+x 900-x ' , a) M a t cap nucleotit ke tiep gom: G = X = 900 nucleotit G M o i gen dot bien b i mat: 90 : (2^ - 1) = 90 : 15 (gen) = nucleotit hay mat cap nucleotit Giai he phiTdng trinh ta c6: A = T = 600 nucleotit - _ Hiidng ddn - -G~3 ^ Hay xac dinh nhffng k i e u bien d d i c6 the xay gen dot bien = 66,85% = > x - l Nhir vay dot bien da lam thay ddi mot cSp G - X bang mot cSp A - T Dpt bien dang thay the" cap nucleotit bkng cSp nucleotit khac B a i 2: Dot bien xay gen B lam mat axit amin thu" cua chuoi pohpeptit gen tdng hpp Hay xac dinh dang dot bien va v i tri dot bien xay gen - r,iv Gen mat mot doan gom nucleotit Suy mach mang ma gdc mat nucleotit ke tiep Do mach mang ma gdc ciia gen dot bien c6 1500 - = 1497 nucleotit hay mach m A R N gen phien ma c6 1497 ribonucleotit So Ian ma (phien ma) tir gen dot bien la: 7485 : 1497 = Ian B a i 5: Gen A quy dinh mau mat l a m mat cap nucleotit va tao alen a hoac a| ^^^./•=v^,:•*.;^ ^^^.;v Gia thie't alen a difdc tao bang mot diTcJng sau day t h i phan tuT protein tu'dng iJng se khdc v d i so protein gen A tdng hdp nhtf the nao? 121 Cty TNHH MTV DWH Khang Vigt Ca'm nang tg 6n va luy$n thi Sinh hgc - Phung Duy Dfl'ng Cho rang triTdng hdp moi axit amin chi mot bp ba xac dinh, va dot bien khong lien quan den codon ket thiic a) Ba cap nucleotit bi mat chiJa trpn mot bp ba ma hoa b) Hai nucleotit thupc mpt bp ba ma hoa, mot nucleotit ke tiep thupc bp ba ke'tiep c) Hau qua cua dot bien d a va b c6 giong hay khong? Tai sao? Gia thiet alen tao dot bien mat ba nucleotit d cac vi tri khac cua gen A thi phan tuT protein gen bi dot bien tong hdp khac vdi protein gen A tong hdp nhu" the nap? Cho biel phan tuf protein gen A tdng hdp c6 198 axit amin va cac axit amin tu'dng i^ng vdi cac vi tri bi bien ddi gen chi mpt bp ba ma hoa quy dinh a) Mat cap nucleotit so 4, so va so 12 b) Mat cap nucleotit so 591, so 594 va so 597 HUdngddn ,,, Sir khac giffa phan tuT protein gen A va alen a tdng hdp a) protein dot bien khac protein binh thiTdng axit amin b) protein dpi bien kem protein binh thrfdng axit amin va c6 mpt axit amin bi thay the j ; c) Khong V i codon diTdc hinh sau dpt bien cua hai trrfdng hdp la khac a a) Tru'dng hdp cap nucleotit bi mat nam vi tri khac nhau: V i tri so thupc codon thu" 2, vi tri so" thupc cpdpn thu' 3, vj tri so 12 thupc codon thi? Tru-dng hdp nay, phan tuT protein alen tdng hdp kem phan tu" protein gen A tdng hdp mpt axit amin va c6 axit amin d dau chuoi polipeptit khac vdi axit amin tu'dng vtng ciia chuoi polipeptit gen A tdng hdp b) Tru-tJng hdp cap nucleotit bj mat nam d cac vi tri 591, 594 va 597: HUdng ddn *' Them cap nucleotit giffa cap so va so se lam thay ddi cac bp ba ma 6a tir codon thuT trd di Vay protein gen dot bien tdng hdp chi c6 axit amin 1? nhait gidng vdi axit amin tiTdng ufng tren phan tuT protein gen A tdng hdp Them mpt cap nucleotit d giiJa cap so 594 va 595 thi se lam thay ddi codon thuf ke tur codon ket thuc i"V i vay protein gen dot bien tdng hdp c6 mpt axit amin cud'i cung khdc vdi axit amin tu'dng iJng cua protein gen A tdng hdp Bai 7: Mpt gen chi huy tdng hdp chudi polipeptit gdm 198 axit amin, c6 ti le X = 0,6 Mpt dot bien xay khong lam thay ddi so' lu'dng nucleotit cua X en nhvfng da lam thay ddi ti le ndi tren \ Khi ti le — gen dot bien = 60,43% hay cho biet: _ + Dot bien thupc dang nao? + So lien ket hidro gen dpt bien thay ddi nhtf the nao? + Chuoi polipeptit cua gen dpt bien khac vdi chupi polipeptit cua gen binh tfdng nhu" the nao? Khi ti le —=59,57%, hay cho biet: + Cau triic cua gen da thay ddi nhiT the nao? '">' * ';«''>^ + So' lien ket hidro gen thay ddi nhiT the' nao? >• • • Hitdngddn ' Chuoi polipeptit cua gen c6 198 axit amin, chiJng to mach mang ma B'ccp 198 + = 200bpba S P nucleotit ciia gen (N) la: 200 x x = 1200 nucleotit Ap dung cong thufc: T + X = - N Khi T = 0,6X Chuoi polipeptit gen a i tdng hdp it hdn chuoi polipeptit gen A tdng hdp mpt axit amin v a c6 axit amin d cudi chuoi khac vdi axit amin tiTdng iJng tren chudi polipeptit gen A tdng hdp Ta c6: 0,6X + X = ^ N = 600=>X = 375; T = 225 Bai 6: Gen A chi huy tdng hdp phan tu" protein gdm 198 axit amin Trong gen dpt bien c6: —=60,43% Dot bien gen lam them cap nucleotit d giiJa cap sd'6 va cap so thi phan i\i protein gen dot bien tdng hdp khac vdi phan tuT protein gen A tdng hdp nhq thenao? T T Ti 16 — cua gen binh thiTdng la — = 0,6 X X Dpt bien lam them cap nucleptit d khoang gii?a cap 594 va 595 thi phan tur protein gen dot bien tdng hdp khac vdi phan tuT protein gen A tdng hdp nhU'the'nao? Gia thiet r^ng dot bien khong anh hiTdng den chtfc n^ng cua codon ke't thuc cua gen 122 t ,| «' r,VT' i!lf>^!f'Km T It' 'n M 'H.I i\ ' Nhir vay ti le — tang chiJng to c6 sir thay the cap G - X b^ng cap A - T X Goi X la SP cap nucleptit bi thay the, ta ce phtfdng trinh: ' ' " •' T-.X 225 + x ^ ^ ^ j X+x 375-x Ca'm nang tir 6n va luy^n thi Sinh hoc - Phung Duy Pgng Cty TNHH MTV DWH Khang Vigt + V a y dot b i e n thuoc dang thay the' cap G - X bkng cap A - T + So lien k e t h i d r o s e b i thay d o i nhiTsau: HUdng ddn ; a) So' N S T cua l o a i k h i bi dot bie'n: Gen dot bien k e m gen binh thi/cfng lien ke't hidro + Chuoi polipeptit cua gen dot bien c6 the khac chuoi polipeptit cua gen bmh thu'dng ve phan axit amin hoac dot bien khong l a m thay doi chuoi polipeptit tijy theo codon trufdc dot bien va codon sau dot bien ma hoa axit amin khac hay cung ma hoa axit amin v* ; T T T i le — = , % So vdi t i le — = 0,6 (cua gen binh thi/cJng) la giam, X X chiJng to CO sirthay the cap A - T b a n g cap G - X ; Goi X la so' cap nucleotit bj thay the' , Ta CO phirong trinh: The khong (2n = 8); the mot (2n = 9); the ba (2n = 11); the ba kep (2n = 12); the bon (2n = 13); the bon kep (2n = 14) b) The 3n (5 X = 15); the 4n (5 X = 20); the 5n (5 X = 25) c) B o N S T CO 2n = 12 la bo N S T cua loai d the ba kep hay the bon d) Bat k i cap N S T tuTOng dong nao cung c6 the them mot N S T va hinh the ba D o vay d loai tren (2n = 10) so l o a i the ba khac c6 the dtfdc hinh la • B a i : Gia sv! rang d cay ca doc diTcfc ba nhiem doi v d i N S T A , sif phoi hcJp va phan l i giffa cac N S T xay hoan toan ngau nhien (tiJc la to' hdp giffa A A va A = 59,57% du'dc tao v d i t i le ngang nhau) Co bao nhieu cay va m o i loai chie'm t i le bao nhieu se dtfdc sinh k h i Giai phu'Ong trinh ta c6: x = cay nhU" vay difdc thu phan bang phan cua cay lufdng b o i binh thiTdng V a y dot bien thuoc dang thay mot cap A - T bang mot cap G - X D o so Hen ke't hidro gen dot bien tang them lien ke't hidro HUclngddn Ca doc difdc the ba d o i v d i NST A , tufc la bp NST cua cay n^y c6 NST B a i : Gen A va gen B nam ke tie'p tren NST protein gen A chi huy tong hop CO 48 axit amin Con protein gen B chi huy tong hdp c6 96 axit amin M o t dot bie'n da lam cho gen noi tren gen C Protein gen C chi huy tong hcfp co 144 axit amin A (AAA) Cay lirdng b o i binh thu'dng c6 NST A ( A A ) Ta c6 sd sau: AA P : AAA X G(P) D o t bien lien quan de'n bao nhieu cap nucleotit va thuoc dang nao cua dot ^iAA:iA 2 A t , ) bien gen? -AAA:-AA 2 Xac dinh chieu dai cua gen C NhiT vay, c6 l o a i cay con, moi loai chiem t i le ^ , tufc la c6 ^ so cay la HUdng dan Protein gen C tong hcJp c6 so axit amin bang tong so' axit amin cua protein gen A va gen B tong hOp D i e u chtfng to dot bie'n gen lien quan tdi the ba, va - cap nucleotit Trong c6 cap nucleotit la bo ba ket thuc cua gen A va cap la bo ba m d dau cua gen B bi mat : ^o Chieu d ^ i cua gen C: [(144 x 3) + 6] x 3,4 A " = 1489,2 A " B a i : M o t loai c6 bo NST 2n = 10 Co bao nhieu NST c6 the diTdodn d: • • AIS:''], -AJ B a i 1 : Nhi?ng phan tich d i truyen te bao hoc cho hay r^ng, c6 hai l o a i chuoi D a y la dang mat mot so' cap nucleotit ke' tie'p va n o i gen ke' can mot gen m d i so cay la lifdng boi binh thifdng khac nhau: Chuoi rCfng liTdng b o i va chuoi nha tam b o i nhiTng l o a i gen A Xiic dinh than cao, troi hoan toan so v d i alen a (than tha'p) K h i gay dot bie'n nhan tao ngiTdi ta da thu diTdc mot so dang tiJ b o i va cac dang chi tao cac giao tijTlu^dng boi c6 kha nang song »' ' ' a) The khong, the mot, the mot kep, the ba, the ba kep, the bon, the bon kep Xac dinh ket qua phan linh ve kieu gen va kieu hinh cua cac phep lai sau: b) T h e n , n , 5n a) P: Aaaa X Aaaa c) Neu bo N S T cua loai b i dot bie'n c6 2n = 12 D o la dot b i e n dang nao? Hay cho biet mot so dSc d i e m quan khac giu-a chuo'i nha va d) Co bao nhieu loai the ba khac nhau, c6 the diTdc hinh b) P: Aaaa x A A a a chuo'i rijfng G i a i thich nguon goc va qua trinh xuat hien chuoi nha Cty TNHH MTV DWH Khang Vigt Ca'm nang ti/ On va luy$n thi Sinh hgc - Phung Duy DO'ng Nhiyng cay c6 kieu gen dong hdp tuT chi cho loai giao tur nhiTng cay dong K h i ket qua cua phep lai cho ti le: a) cao : thap b ) cao : thap c ) 1 cao : thap d) 35 cao : thap T h i k i e u gen cua P c6 the nhu" the nao? hdp t ^ troi khong the c6 sir phan tinh k h i l a i Do d d , chi c6 c i c cay aa, aaa, aaaa la phii hdp Tijf do, ta thay muon c6 ke't qua lai phan tinh cao : thap thi kieu gen cua P CO the nhiT sau: P: Aa x aa Hoac P: Aa x aaa Hoac P: Aa x aaaa Hitdng dan Xac dinh ket qua phep l a i : a) P G(P) : Aaaa x Aaaa : A a , aa A a , aa l A A a a : 2Aaaa: laaaa Aaaa m\: G(P) x —AA:—Aa:—aa 6 AAaa ^ -AA:—Aa:—aa 6 y f l A A A A : A A A a : 18 A A a a : Aaaa: laaaa [35 cao: tha'p Chuol nha so v d i chuoi riifng c6 lufdng A D N cao hdn, tong hdp chat hint cri khong CO kha nang sinh giao tuT binh thtfcfng nen khong cd hat nhtf chuoi r t o g Co the cho rang chuol nha c6 nguon goc tuT chuoi r t o g : Trong truTdng hdp dac biet, tac nhan gay dot bien tac dong vao luc giam phan, l a m te liet sir hinh thoi v6 sac, dan den cac cap NST khong phan li tao giao tuT 2n L o a i giao tuT k e l hdp v d i giao tuT binh thiTdng (n) thu tinh se tao hdp tu^ 3n phat trien cay chuol 3n NhSng cay chuoi 3n c6 qua to, ngon, khong hat da diTdc ngiTdi giff lai va nhan len bKng sinh san sinh diTSng tao nen chuol nha ' aa K M Hoac P: Aaaa x aaa i Bai 13: Gia thiet cap NST tffdng ddng mang cac cap alen bieu thi bang cac I so'nhffsau: r 2' 3' 4' 6' 7' 8' 9' -'ife a) Hay vie't cd che dan den sff bien ddi vi tri ciia gen tren NST b) Sff bien ddi v i tri cua gen tren NST cd phai chi dot bien cau trffc NST hay khong? Tai sao? HUdngddn a) Vie't cd che dan den sff bien ddi v i tri cua gen tren NST + Bie'n ddi lien quan de^n mot NST: - Dao doan: Doan bi dao CO chffa hoSc khong chffa tam dong: hoac 1' 2' 3' 4' - Chuyen vi tri cua gen: hoSc 4" 2' 3' 1' , , , - Ma't doan d ben cua canh lam cho gen trffdc dSy c^ch xa nhich lai gan tren mot NST:1 4, 4 hay 1' 3' 4', 1' 4' - Trao ddi cheo khong can giffa cromatit cua mot NST kep: 2 34 hoac r ' ' ' M ' ' ' + Bien ddi lien quan den hoSc nhieu NST: -'^ - Trao ddi cheo khong can giffa cromatit ciia NST tffdng ddng:,' y 2' 3' 4' ^ r 2' 3' 4' - Chuyen doan tffdng hd: - Chuyen doan khong tffdng ho: 3; • 9; • + Bien ddi khong phai la dot bien ca'u true Trao ddi cheo ddng deu xay giffa hai NST tffdng ddng: - - Ruoi cai mang NST X, mdi chiec chffa doan 16A da xay trao ddi cheo khong can tao NST X c6 doan 16A va mot NST X c6 doan 16A Ruoi cai dot bien se tao trffng X c6 chffa doan 16A Loai trffng ket hdp vdi tinh trung Y se tao rudi dffc mang NST X c6 chffa doan 16A (mat rat det) I'llA - Sff phdi hdp giffa trffng chffa NST X c6 doan 16A vdi tinh trung X c6 doan, hay doan 16A se tao rudi c^i di hdp, m^t ra't det nhUng khong gidiig het trffdng hdp ca NST X deu c6 doan 16A r 2' 3' 4" r " ^ 2' 3' 4' Sff bien ddi vi tri cua gen tren NST khong chi dot bien cau true NST ma trao ddi cheo ddng deu (can) giffa cromatit cua mot NST k6p hoSc giffa cac cromatit thuoc NST tffdng ddng Bai 14: Gia thie't c6 mot NST mang cac gen c6 chieu dai bang Do bi chieu xa, phan tff A D N tao nen NST bi dfft mot doan tffdng ffng vdi 20 ARN thong tin va lam ma't di 5% tdng so gen cua NST 66 Khi phan tff A D N bi dot bien tff nhan doi da doi hoi moi trffdng n6i bao cung cap 38000 nucleotit tff • 129 Cam nang tif on va luyen thi Sinh hoc - Phung Duy Ddng a) Dot bie'n noi tren thuoc loai dot bien gi? b) Xac dinh so" gen tren NST c) X^c dinh chieu dai trung binh cua gen Hitdngddn a) Dot bien noi tren la dot bien cau true NST dang mat doan vi doan bi diJt tiTdng u-ng vcti 20 ARN thong tin hay 20 gen b) Xac dinh so' gen tren NST: Doan bi mat gom 20 gen ke" tiep va chiem 5% tdng so gen cua NST Do NST c6.(20 : 5) x 100 = 400 gen c) So gen cua NST sau bi dut la: 400 - 20 = 380 gen So nucleotit moi trifdng noi bao cung cap cho 380 gen tu" nhan doi la 38000 nucleotit Do so nucleotit cua moi gen la: 38000 : 380 = 100 nucleotit Vay chieu dai trung binh cua mot gen la: 3,4 A" X 50 = 170 A" Bai 15: Bie't cac bp ba ma da ma hoa cac axit amin nhu" sau: UXU: Xerin; AXA: Treonin; UAU: Tirozin; AAG: Lizin; GUU: Glixin; XXX: Prolin; GXA: Alanin; AUA: Izolcfxin; GAA: Glutamic; UGG: Triptofan Mot doan gen binh thu'dng da dieu khien tdng hdp mot doan cua chuoi polipeptit CO trat tU" cac axit amin la: Xerin - Treomin - Prolin - Lizin - Tirozin - Glixin - Alanin - Glutamic - Izoldxin - Triptofan Gia thiet rang riboxom luon luon tru'cJt tren phan tu^ mARN theo chieu tuf trai sang phai Hay viet trat tif cac nucleotit cua doan gen ttfdng iJng Khi CO hicn tu'rfng dot bien dao doan NST chuTa doan gen noi tren thi dao doan polipeptit tu'dng iJng c6 cac axit amin sap xe'p theo trat tiT nao? Hudng dan Trat tir sap xcp cac ribonucleotit cua doan mARN: UXU - AXA - XXX AAG - UAU - GGU - GXA - GAA - AUA - UGG - Trat tiT sap xe'p cac nucleotit mach mang ma goc: TAT - TGT - TTX - ATA - XXA - XGT - XTT - TAT - AXX - Trat tuf sap xe'p cac nucleotit mach bd sung: ATA - AXA - XXX - AAG - TAT - GGT - GXA - GAA - ATX - TGG Dot bie'n dao doan lam cho trat tif cac nucleotit mach mang ma goc dao ngu'dc Vi vay trat tu" cac ribonucleotit mARN cung bi dao ngUdc, dan tdi trat tiT cac axit amin bi dao ngu'dc: Triptofan - Isoldxin - Glutamic - Alanin - Glixin - Tirozin - Lizin Prolin - Treomin - Xerin Bai 16: Doan khdi dau cua mot gen binh thiTdng chiJa cac nucleotit mach khuon nhU" sau: ATG GXA TGX AXT X GAT Gia su" rang qua trinh dot bien nucleotit thu" la X bi thay thebdi A Hoi CO bao nhieu axit amin bi thay ddi d phan tu" protein diTdc tdng hdp? Cty TIMHH MTV DVVH Khang Vigt Gia sij" nucleotit thu" ay bi mat di thi c6 bao nhieu axit amin bi thay ddi d phan tu* protein du'dc tdng hdp? Ne'u them vao sau nucleotit thi? la A mot nucleotit X thi hau qua the hien nhif the nao d phan tuf protein diTdc tdng hdp? Gia thiet rang qua trinh dich ma xay theo hu'dtng tiif trai sang phai d phan tu" mARN du'dc tijf gen HUdng ddn Nnucleotit thu" la X nam bo ba thu" hai la GXA bi thay thebSi A thi chi b p ba thuf bi bie'n ddi GAA Do chi mot axit amin bi thay ddi phan tuT protein du'dc tdng hdp Nucleotit thi? bi ma't di se dan de'n thay ddi khung dich ma tiif nucleotit thiJ Do tiJf axit amin thiJ hai trd di chuoi polipeptit se bi thay ddi Ne'u them A vao sau nucleotit thu* thi khung dich ma bi thay ddi tuT nucleotit thiJ Do tiJT axit amin thi? hai trd di chudi polipeptit bi thay ddi Nhifng sir thay ddi khong gidng d phan cic axit amin so vdi trUdng hdp tren Bai 17: Gia thiet NST thi? nhat c6 gen, NST thu" hai c6 gen Cac gen tren NST ke tiep lam mot phan tuT ADN Cac gen deu dai 5100 A" Phan X\i ADN CO NST thtf nhat chtfa 20% Adenin, phan tuT ADN c6 NST UhiJhai chiJa 15% Adenin j Do dot bie'n cau true NST, moi phan tuT ADN da dut mot doan dai bang va chuyen doan cho de trd hai phan tuf ADN mdi Phan tuT ADN mdi ' ma phan Idn vat chat di truyen c6 nguon goc tif NST thi? nhat da cd so lien ket hidro cua mot loai nucleotit giam di la 2100 so vdi so lien ket hidro cua mot loai nucleotit phan ttjf ADN nkm d NST thi? nhat chifa dot bie'n Tinh chieu dai cua moi phan tuf ADN chtfa dot bien " S" So lU'dng tufng loai nucleotit mdi phan i\i ADN chu'a dot bie'n la bao nhieu? So lufdng tufng loai nucleotit moi phan tuf ADN mdi diTdc hinh sau dot bie'n la bao nhieu? HUdngddn Chieu dai cua mdi phan tufADN chu'a dot bien: n - Phantu'ADNtrongNSTthi?nhat:5100A"x7 = 35700A" Mi A=360... dong O sinh vat \idng boi c6 cac dang chinh nhiT:" the khong (2n - 2) , thg ot (2n - 1), the mot kep (2n - - 1), the ba (2n + 1), the ba kep (2n + 1+ 1), ihe boo (2n + 2) , the bon kep (2n + + 2) ... hinh la: 25 6 + 25 6 = 5 12 - So' te bao 2n du^dc hinh tu" Ian nguyen phan cuo'i ciang: 5 12 ' = 128 te bao ri':.'; 128 = 2' Vay tirte'bao sinh due 2n dau tien da nguyen phan lien tiep Ian 2n = — ^