Di truyền, tiến hoá và sinh thái học

TRINH NGUYEN GIAO - LE DINH TRUNG

DI TRUYEN, TigN HOA
VA SINH THAI HOC

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NHA XUAT BAN GIAO DUC VIET
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TRINH NGUYEN GIA() - LE DINH TRUNG

DI TRUYEN, TIEN HOA
VA SINH THAI HOC

TAN TAO UNIVERSITY LIBRARY

NHA XUAT BAN GIA() DUC VIET NAM

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Cong ti CP Dich vu xua't ban Gido duc tai Da Ming - Nha xugt ban Gasp duc Viet Nam

giu quy6n cOng 136 tac
207-2009/CXB/16-344/GD

Ma. s6 : 81817N9 — CPD


Nol DALJ

Di truyen, Tio'n hoa va Sinh thai hoc la mot link vuc toong doi kho trong
chuong trinh va not dung SGK Sinh hoc 12 va luOn chiem mOt só luong lon cac
cau hOi trong cac ki thi tot nghiep TIIPT, tuyen sinh vao Cao dang — Dai hoc.
De gni') cac em hoc sinh chic (Ring trong hoc tap va On tap cac phan nay, chting
tOi bien sop cu6n "1)i truyen, Tin hoa va Sinh thai hpc".
Cau tick cu6n sach gom 3 phan :
. Phan nam :

DI TRUYfIN HOC

Phan sau : •

TIEN HOA

Phan by :

SINH THAI HOC

"Prong m6i phan g6m cac chuong theo cat,. trtic ciia SGK Sinh hoc 12 nang
cao. 'Prong m61 chuong, chCing tOi deu gidi thieu nhimg kien thirc co ban nhat
va he th6ng cau hOi trac nghiem.
Ike thu throe kel qua t6t trong qua trinh hoc tap, cac em nen hoc ki nOi

dung kien thtic co ban cua timg chuong truOc khi tra tai cac cau hoi trac
nghiem. Sau he thOng cau hOi luyen tap la phan dap an.
Day la cu6n sach tham khao, mai throe xu4t ban Ian dau nen kho tranh
khOi thieu sot. Chting t6i mong nhan -duck; 9 kien Op 9 cita cac em hoc sinh va
qu9 thing nghiep de kin tai ban sau sach duoc t6t hon.
"TAP THE- TAC GIA

3



■
-■

DI TRUYEN HOC

Phan nem.
Chu'ang I

CC; CHE DI TRUYEN VA BIEN DI
A. KIEN TFRIC CO BAN CAN NHO
I. CAC KHAI NIEM
1. Gen : la I doan cita phan tir ADN mang thong tin ma hoa mot chuoi
pOlipeptit hay ARN.

2. ma di truyen : la trinh to cac nucleOtit trong gen quy dinh trinh to cac
•axit amin trong phan tir prOtein do gen chi huy tong hop.
.
3. Ma bn ba : cu' 3 nucleOtit dting kd tiOp nhau trong gen chi phoi sir co mat
mot axit amin trong san pham prOtein hay gift chdc nang ket thtic chuoi pOlipeptit

goi la ma bO ba.
4. Nhan doi phan tir ADN : la co chd tir snot phan tir ADN me do tac &Ong
cita enzim da tao nen 2 phan tir ADN con, trong m6i phan tir ADN Om 2 mach
(mot mach cil va mot mach mdi) theo nguyen tAc ban bao ton, hoan toast giOng
ADN me.
5. Phien ma : su truydn thong tin di truyen tir mot mach don dia gen call
trite (mach g6c) sang phan tit ARN theo nguyen tdc b6 sung (NTBS).
6. Dich ma : qua trinh 'tong hop prOtein xay ra 6 ribOxOm Om 2 giai doan :
hoat hod axit amin va tang hop protein dua tren nguyen tEic ma bO ba va dOi ma di
truyen co sir tham gia cua cac loaf ARN va cac enzim.
7. RibOxom : la mot to chtic cgu true Om 2 tiau the (tiau thd be va tiau thd
16n) duck cLiu tao b6i cac phan tir protein va cac loai rARN tham gia trkrc tidp vao
qua trinh tang hop prOtein, khi getn vao mARN tai vi trf nhan bidtva dich chuyen
arng btrerc tren mARN de thuc hien qua trinh doi ma di truyen giCra 130 ba doi ma
tren tARN v6i 130 ba ma phien tren mARN de tao ra san pharn la prOtein.
8. ARN van chuyn (tARN) : la phan tir ARN mach don &roe con xoan
thanh cac thug tren ma tARN, có 2 130 phan quan trong do lab() ba dOi ma va doan
mang axit amin co tan ding la adenin.
5


9. ARN thOng tin (mARN) : la phan ti mach don duoc tong hop ta gen eau
tine grim co 110 ha m6 ddu (AUG) va cac bc) ba ma hod axit amin trong phan tir
protein va b6 ha ket thUc.
10. Dieu hoa hoat thing dm gen : la qua trinh dieu hoa hoat eking gen trong
phien ma va dich ma di truyen nham dam bao tad ra mot luong san pham phit'hop
theo yeu eau hoat citing sinh 11 cUa to bao.
11. Dot bien gen : la nhling bien d6i nhe )(ay ra trong can true cUa gen, lien
quan den mot hay mot so cap nucleOtit do tac nhan dot Hen hay-do cac cdc sir co
ngau nhien trong qua trinh sao chep ADN. Cac d6t Nen có the di truyen throe qua

con duOng sinh san.
12. Nhkm sac the (NST) : la vat chat di truyen doge nhuOm mau bang
thilOc nhuOm kiem tInh, c0 hinh clang va kich thu'dc dac trang, diroc eau tao bOi 2
thanh phan chinh do la cac protein histOn va ADN, don vi co ban ciia nhiem sac
the 1a cac nucloOxom.
13. NueleOx6m : M6i nucleOxiim gOm 8 phan tix protein histOn lien ket vol
3
nhau tao thanh mot tieu the hinh cau det, phia ngoai duoc quan -boi 1- yang xoan
4
ADN CO khoang 146 cap nucl'eOtit.
14. DM bi6n cau true nhii.‘;rn sac the : la nhimg hien d(ii trong cau ink
NST do tac nhan dot Nen lam sap xep lai nhang khOi gen do do lam thay d6i
hinh clang, can true NST.
15. DM bien so luting NST : la six thay d6i dot ng01 ye mat s6 luong NST
trong to bao do cac tac nhan gay d01 bien hoac rOi loan qua trinh phan bao, mac du
NST van nhan dOi binh thuong, nhung do day to vO sac bi cat din hoac khOng hinh
thanh throc vi vay NST khOng phan Ii throc ye cac cut ci.la to bao. Neu xay ra tren
loan b0 b0 NST se tao nen clang da bOi the, nen xay rad tang cap NST se tad nen
Bang di bOi the (loch b6i).
16. DM bier( tech bOi : la nhung bien d6i ye so luong NST xay ra 6 mot hay
mOt s6 cap NST tirong (long.
17. DOt hien da bni : co 2 loai la to da bOi va di da bOi.
—Tu. da b6i : la six tang mot so nguyen Ian b6 NST don bOi-cita loai (3n,
4n, 5n...).
—Di da bOi : lir hien tuong ca 2 N.) NST cOa ca 2 loai cUng ton tai trong mot
to bac) la' do qua trinh lai xa.
6


H. CAU TWA: CHUNG CUA GEN CAU TRU. C

—VC ban chat, gen cluqc tao boi cac nucloOtit (Om 4 loai A, T, G, X) ; cac
gen throe dac trung b6i s6 luong, thanh phan, trinh to phan b6 cac nucleOtit, b6i ti
A+T
le
G+X
—M6i gen cau truc Om 3 viing :
+ Wing diet' hoa : nam .6 phan dau cna gen, mang tin hieu khui dung va
kiem soat qua triph phien ma.
• + Viing ma hoa : mang thOng tin ma hod cac axit amin.
+ Wing ket thilc : nam 6 cu6i gen, mang tin hieu 1(61 thtic phien
III. DAC DIEM CUA MA DI TRUYEN
1. MA di truyen là ma bo ba (da &roc chung minh va duoc giai ma vao nam
1966) : CO 64 1)0 ba ma hoa, trong do co 61 1)0 có nghia ma hoa axit amin (trong
do có b0 ba AUG ma hoa axit amin m6 dau) va ba b0 ma ket thfic : UAG, UAA,
UGA chi lam nhiem vu ket thdc chuoi pOlipeptit &roc tong hop.
2. MA di truyen &roc doc tit mot di6m dung (diem xac .dinh) tren gen tong
b6 ba. rnicleatit, khOng cb6ng cheo len nhau cho den het phan cna gen.
3. MA di truyen co tinh ph6 Nen, co nghia la tat ca cac loai deu diing chung
64 b6 ma di truyen (chi tr6 mot vai ngoai le).
4. MA di truyen CO tinh dac hieu, tut la mot b0 ba chi ma hod mot loai
axit amin.
5.. MA di truy6n co tinh thoai hoa, tat la có tru6ng hop nhieu 130 ba cnng xac.
dinh mot axit amin (trit 2 ngoai le AUG, UGG).
IV. QUA TRINH NHAN DOI ADN
— Qua trinh tai ban ADN 6 sinh vat nhan so va nhan thuc cling có nhiing
diem khac nhau do la khac ve he enzim xnc tac, v6 so luting don vi tai ban. O day
chi tenth bay sty tai ban ADN 6 sinh vat nhan ihuc dien ra tren mot don vi tai .ban.
. — Qua trinh tai ban ADN dien ra o pha S cua chu ki to bao. Day la bu&c
chuan bi, vat chat di truyen tang len gap dOi cho qua trinh phan bao nguyen phan
va giam phan.

—Co the tong hop ADN co the van tat theo 3 buck :
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+ Budc 1 : Thao xodn phan tir ADN : nhd cac enzim than xodn, hai mach
don cUa phan td ADN tacit dan nhau ra tao nen chac tai ban hinh chit' Y de 10 ra 2
mach don de thuc hien qua trinh tai ban.
+ Budc 2 : T6ng hop cac mach don ADN mdi : enzim ADN pOlimeraza sir
dung 2 mach don me lam khuon de t6ng hop nen mach don mdi (trudc khi tong hop,
co skr t6ng hop doan m6i ARN de tao nen nh6m 3'0H tao dieu kien gan cac
nucleOtit dal mOi tru6ng tao nen mach mdi theo NTBS). VI ADN pOlimeraza chi
t6ng hop mach mdi theo chieu 5' — 3', nen tren mach khuOn 3' — 5' mach mdi duoc
t6ng hop lien tuc, con tren mach khuOn con lai c6 chieu 5' — 3' mach mdi dopy t6ng
hop ngdt quang tirng doan ngan (m6i doan goi 1a doan Okazaki). Sau d6 cac doan
Okazaki throe n6i lai vdi nhau nh6 enzim not de tao lai mach don moihoan chinh.
+ Budc 3 : Hai phan tir ADN con duoc tao thanh, trong m6i ADN con c6
mot mach -là nguyen lieu cu, mOt mach la nguyen lieu mdi duoc tao nen theo
nguyen tdc ban bao ton.
•
Sr tai ban ADN la co s6 hinh. thanh NST nham dam bac) so di truyen on dinh
qua car the" he cap dO phan tir.
V. CO CHE MIEN MA DI TRUYEN
Gorn 3 busk co ban sau :
—M6 dau : ARN pOlimeraza barn vao vimg khdi dau lam gen cau trite thao
xodn, mach khuOn dm gen c6 chieu 3' — 5' 10 ra lam khuOn de kh6i dau t6ng hop
ARN tai vi tri (lac hieu.
- Keo dai : ARN pOlimeraza chuyen Bich tren mach khuOn dm gen theo
chieu 3' — 5' de t6ng hop ARN theo nguyen tdc b6 sung (A—U, G—X) theo chieu
5' — 3'.
—Kat auk : Enzim 'ARN pOlimeraza di chuyen tdi cu6i gen gap tin hieu kat

thlic thl qua trinh phien ma d'u'ng lai, giai phong phan tir ARN. So ket thtic qua
tenth phien ma nh6 vao cac yau to ket thuc. (13 sinh vat nhan sox, phan td mARN
doge tang hop tham gia ngay vao qua trinh dich ma. Con d sinh vat nhan thuc,
mARN sau khi duoc t6ng hop chi mdi la san pham the.' do do phai nhd enzim cat
136 cac doan vo nghia, n6i cac doan c6 nghia lai vdi nhau de tao nen mARN trudng
thanh tham gia vao qua trinh dich ma.
Stx t6ng hop ARN la co s6 de thuc hien qua trinh tong hop protein it td- bao chat,
dam bao sit truyen thong tin di truyen tir gen sang san pham prOtein.
Co 3 loai ARN duoc t6ng hop vdi cac chic nang khac nhau :
8


—mARN : true tiep la ban phien thong tin di truyen cna gen eau true lam
khuOn de t6ng hop prOtein. C3 sinh vat nhan so, mARN duoc tang hop thanh timg
nhom gom nhieu mARN. Con d sinh vat nhan thuc, mARN duoc t6ng hop thanh
ding mARN don le.
—rARN : .ket hop voi cac protein tao nen cac ribOxOm, moi ribOxOm Om 2
tidu the, khi tang hop prOtein chting lien ket voi nhau, tiep xtic voi mARN va
chuyen dich tang buOc tren dO, mai buoy la mot b6 ba.
— tARN : mang cac axit amin thanh dung lien tuc t6i riboxom. Tai day,
chung thuc hien co the &Si ma di truyen gitla b6 ba dOi ma tren tARN voi bq ba
ma phien tren mARN lap rap theo nguyen tac b6 sung de dat chinh xac vi trf timg
axit amin vao chuoi pOlipeptit.
VI. CO CHE DICH MA DI TRUYgN
GOrri 2 giai clop :
1. Hoat hod axit amin
Cac axit amin (aa) sau khi duoc dieu den to bao chat, duoi tat; dung ciia mOt
loai enzim, chimg duoc hoat hoti bang each lien ket voi hop chat giau nang luting
„la ATP va gan vao timg tARN tao nen pink hop aa—tARN de dua den riboxom
tang hop prOtein. •

2. Ting hop chuoi polipeptit : gOm 3 btroc co ban •
—MO dau chuoi pOlipeptit Tien the be dm ribOxOm gan voi mARN o vi trf
nhan biet, cOdon and dau AUG tren mARN gan voi bO ba dOi ma cua tARN van
chuyen axit amin and dati UAX. Tieu the 16n ciia ribOxOm ket hop voi ti6u the be
tao nen ribOxOm hoar' chinh. tARN mang axit. amin and dau foocmin metiOnin
(fMet-tARN) tien vao vi trf codon mO dau tren mARN
—Keo dai chuoi pOlipeptit : COdon thin 1 nam sau cOdon and dau AUG tren
mARN duoc lien ket voi anticOdon (int tARN axit amin thin 1 (aa i —tARN) theo
NTBS, mot lien ket peptit duoc hinh thanh giira axit amin md dau voi axit.amin
thir nhat (fMet-aa i ) bdi mot loai enzim xuc tac, clang thdi voi qua trinh do thi
iARN vita tham gia se rdi khOi ribOxOm. RibOxOm lai chuyen dich sang 130 ba
thin 2 tren mARN, aa,—tARN tien vao ribOxOm, dOi ma ciia no lai khop voi ma
thir 2 tren mARN theo NTBS, lien ket peptit aid 2 lai duoc hinh thanh giita aa i
aa? . RibOxOm lai chuyen dich sang bO ba thd 3, lap lai theo co the tren, cho
den tan 130 ba tiep giap voi 1)0 ba ket thtic thi qua trinh keo dai chuoi polipeptit
dimg lai, san pham duoc tao ra aa1 -T-aa2—aa3...aan nhung van con gAn voi tARN
tren khung dich ma.
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—Ket thtic chu6i pOlipeptit : Rib(^mem chuyen dich sang be ba ket thuc tren
mARN thi qua trinh dich ma hoan tat (ltic nay khOng din them met axit amin nao
vat) nila). Nh6 hoat Ong cita enzim- ma axit amin m6 dau duoc cat khei chu6i
pOlipeptit, cac tidu thd ribOxOm tach r6i nhau ra, aan—tARN tach khOi ribOxern,
giai phong chu6i pOlipeptit. Chu6i pOlipeptit nay hinh thanh eau trite khOng gian
cac cap de thuc hien cac chile nang sinh hoc trong to bao.
—De tang cuing hieu suat tong hop prOtein thu6ng thi tren mai mARN c6
nhieu ribOxem cling hoat (king tact nen met chu6i pOlixOm.
Su tCing hop prOtein la co so dam bao cho gen thuc hien vice hinh thanh tinh
trang.theo so do bleu hien co the phan cUa hien tuong di truyen

Gen —> mARN —> protein —> tinh trang.

VII. DLEU HOA HOAT BONG CUA GEN
L Cae cap (10 dieu hoa hoat Ong etia gen

- 6 to bao nhan so (khOng có Mang nhan) : su phien ma, dich ma thu6ng dien
ra (Jong th6i nen sudieu hoa hoat Ong gen chi yeti lien hanh o cap de phien ma.
—
bao nhan thus : phien ma )(ay ra trong nhan, dich ma tien hanh o to
bao chat, nen six dieu hoa khOng xay ra dong.th6i, ma rat ph(tc tap, duoc lien hanh
o nhieu cap de lir mac. ADN (truck phien ma) den mire phien 'ma, dich ma va cii
sau dich
2. Dieu hoit hoat Ong etia gen
a) Dieu hoa haat deing ctia gen a sinh vat.nhan so' :
MO hinh dieu hoa operon : ine hinh duoc xay dung dim Wen cOng trinh cua 2
nha khoa hoc F. Jacep va J. MOne nghien eau tren vi khua'n duOng runt E. coll.
Met operon gam cac gen call true kidm coat tong hop cac pOlipeptit có lien quan
ve chat nang ; \Tung van hanh chi ph6i hoat Ong cUa gen cau true (0 : operator) ;
\fling khOri Ong 6 day la not ARN pOlimeraza barn vao va kh6i dau phien ma.
Ngoai ra (i 1 gen kith: khOng nam trong operon, nhang lai giu vai tr6 quan trong
trong dieu hoa hoat &Ong cUa gen.
b) Dieu hoa how dang caa gen a sinh vat nhan thgr :
sinh vat nhan thuc, su dieu hoa hoat &Ong cUa gen rat ph(rc tap va 6 nhieu
mac de khac nhau : o mire chat nhiem site, mac phien ma, sau phien ma, mire dich
ma, mire sau dich ma.
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VIII. CAU 'MCC VA CHCC NANG CUA

NST

1. Ciiu &tic NST
- Vat chfit di truyen 6 virut có the la mach kep hay mach don ADN, mot s'6
virut có vat chat di truyen la ARN. CS sinh vat nhan so, dien hinh 1a vi khuan, vat
dial di truyen la ADN mach kep, clang yang, khOng lien ket voi prOtein.
- C3 sinh vat nhan thou, vat chal di: truyen duoc t6 chdc lai thanh cac NST.
NST duce can tao bOi 2 thanh phan chinh do la ADN va prOtein loci histOn. Don vi
co ban cau triic nen NST Ia nucleOx6m, cac nucleOxOm tar) thanh soi co .ban co
throng kinh 11nm (mtIc xoan 1). Seri co ban (long xoan thin cap tr6 thanh soi nhiem
sac CO dung kinh 30nm (mcrc xoan 2). Soi nay lai tiep tuc (ing xoan tr6 thanh
clang sieu xoan có dueng kinh 300nm (milt xoan 3). Dang sieu .xoan la co s6 de
tao ra crOmatit CO mire dO xoan cao hon co ddeng kinh 700nm. Dieu nay cho phep
giai thich tai sao o ea: sinh vat nhan thdc chieu dai icing Ong cha ADN trong to
bao la rat Ion, nhung lai co the china dung trong NST CO kich thu6c rat nho.
MOi NST trong cac kl phan bao luOn Nen dOi Wirth thai dam bao cho ADN
den NST thtrc hien cac chirc nang di truyen, m6i NST co 3 bOphan chU yeu : tam
Ong, dau mint va trinh tkr khi dau tai ban.
2. Chac nang NST
- Luru gi[ va truyen dat thOng tin di truyen qua cac the he cau true, goi la
gen died hoa R (R : Regualator).
—Co elle diet, hoa hoat Ong cha op(3ron Lac :
+ Khi mOi truOng khOng co lactOzo : gen dieu hoa hoat dOng san xuSt
prOtein crc che, prOtein nay nhanh chOng duoc hoat hoa, bien d6i thanh trang thai
hoat Ong gall vac vOng chi huy• (0) ngan can hoat Ong cha enzim phien ma do
do cac mARN khOng duoc tang hop:
+ Khi mOi it-11611g có lact6zo : m6t s6 phan tir lactOzo duce coi nha chat cam
ang lien ket voi prOtein crc che duoc tong hop ttr gen R, lam bien d6i cau hinh khOng
gian ha chieu cha no, khien prOtein ire che khOng lien VI duoc voi vimg operator
(tai viing 0), do do ARN pOlimeraza lien ket duoc voi prOtein de den hinh phien

ma, tao nen cac phan td mARN tin cac gen cau true, cac mARN nay dich ma hinh
thanh cac enzim phan giai da6ng kictOzo. Sau do khi duel-1g lactOzo phan giai het ail
prOtein Crc che lai hen ket voi viing 0 lam ngdrig qua trinh phien ma.
IX. DOT BIEN
1. DOt bien gen
—La nhirng d6t Nen nhO )(ay ra trong cau irk phan tin circa gen.
—CO 4 clang dot bien gen : mat nucleOtii, them nucleOtit, thay the nucleOtit,
dao vi tri nucleOtit.
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C6 the phat sinh dOt [lien gen :
+ Su bat cap khOng dUng trong tai ban ADN : Do cat bazo nito thuOng ton
tai 2 clang cau true (dang linking va dang hiem), clang hiem (116 bien) c6 nhCmg vi
tri lien ket hidrO bi thay del lam ket cap sai trong tai ban (rich! guanin dang hiem
ket cap voi timin trong tai ban gay nen 01 Nen G—X Nen d6i thanh A—T).
+ Tat' long cna cac tac nhan gay dOt Nen : Tac Ong cna- tac nhan vat 11 (tia
cut tins tao dimetimin), tac nhan hoa hoc (5—brOm iffaxin gay dOt bien thay the
A—T hang G—X), tac nhan sinh hoc nhu mot so virut cling gay nen &it bien gen
(virut viem gan 13, virut Herpes...).
— flau qua cna ckit Nen gen :
+ DOt bien gen c6 the c6 loi, (xi hal hoac trung tinh.
+ Cung cap nguyen lieu cho qua trinh chon giOng va tie-n hod..
•— Tinh chat bleu hien cUa dOt Nen gen :
+ Dot Nen gen khi phat sinh c6 the truyen lai cho the he sau qua co the tai
ban ADN.
+ flot bien gen khi phat sinh trong giam phan se' di vao giao tir va qua thu
tinh di vao hop tn. Neu la dOt. Nen trOi se bleu hien ngay thanh kieu hinh, lieu la
dOt Nen Ian se ton tai trong hop tiS 6 trang thai di hop, roi qua qua trinh giao phOi
se Ian rung cham chap trong quan the, trong loci den mot th6i diem nhat dinh se

bleu hien ra kieu hinh hic 6 dang thing hop Ian.
+ Neu dOt Nen xay ra trong nguyen phan se ton tai 6 to bao xOma r6i ducfc
nhan len trong mot mo, bidu hien 6 1 phan co the tao nen the kham. DOt Nen
xOma c6 the nhan len qua sinh sari sinh duang. DOt bien xay ra 6 kin nguyen phan
(tau tien cua hop tn 6 giai (loan 2 den 8 to bao till se di vao qua trinh hinh thanh
giao tir va truyen lai cho d6i sau qua sinh sins hiru tinh.

2. DOt bien cau true NST
Ole dangdot bien cau talc NST va vai trO cna no
+ Mat doan : la six rui rung tUng doan NST do cac tac nhan clOt bien, lam
giam s6 luting gen, mat can bang gen. Neu mat doan dai thu6ng gay chef (ri drt
Mat (loan NST 21 6 nga6i gay ra ung this mau). MOt so ga6l-1g hop mat down nho
ngO, ru6i giam thi lai khOng anh hirong gi.
+ Lap doan : la mot doan NST nao d6 ire)) NST có the lap lai mot hay nhieu
Ian, lam tang s6 luting gen. Lap doan NST c6 the lam tang bidu hien tinh trang
(nhu' lap doan 6 dai mach lam hoat tinh enzim amilaza tang len), mot s6 lap doan
lai c6 hal (nhu lap doan 16A 6 ruei Siam lam cho mat hinh can tr6 thanh mat det).
Nhin chung lap doan NST khOng gay hau qua Ion nhu mat clop NST.
12


+ Dao doan NST : la met 'Joan NST dirt ra rOi ciao nguoc 180° va not lai lam
thay dei trinh to phan 1.?6 gen tren NST, dao clop c6 the china tam Ong hoc
khOng 'china tam Ong. Del Nen ciao doan c6 the hoac- khOng anh huOng t6i sac
song, vat lieu di truyen khOng mat di ma chi sap xep lai dodo Op phan tao ra su
da dang gida cac thd trong loci (vi du 6 ruOi gigm da phut hien 12 dang dao clop
c NST s6 3 On lien v6i kha nang thIch (mg voi cac nguang nhiet cUa mOi throng).
+ Chuyen doan NST : la six trao dei (loan gida cac NST, lam cho met se gen
6 nh6m lien kat nay chuyen sang nhorn lien ketkhac. Doi khi chuyen clop lam
hop nhgt cac NST, giam s6 luting NST, day la co the hinh thanh loci tae thoi. Cac

chuyen (loan 16.n thireng gay chet va mat kha nang sinh san.
—\-1 nghia cUa dot bien eau true NST :
+ Dot Hen cau trtic NST lam thay dOi cau talc he gen clan toi each li sinh
san la met trong nhung con du6ng hinh thanh loci moi.
• + Trong chon gi6ng, su to hop lai cac gen do (let bien tao ra nguon nguyen
lieu phong phu de tao giong moi.
3. DOt bi6n so luting NST
Bao gem 2 loai :
—Dot Nen lech bei : la nhang bien d6i ye s6 luting NST chi xay ra o 1 hay
met s6 cap NST.
+ G6m cac dang : the khOng (2n — 2), the met (2n — 1), the met kep (2n — 1 — 1),
the ba (2n + 1), the bon (2n + 2), the bOri kep (2n + 2 + 2)...
+ Dot bien lech bei CO the )(ay ra trong giam phan do khong phan li 6 met
hay met s6 cap NST tao nen giao tin leCh bei (thira (thieu) 1 hay met s6 NST)
• giao ti:r nay kat hop v6i giao tin binh thu6ng tao nen hop tin lech bei. Neu xay ra
trong nguyen phan 6 cac to bao sinh duang tao nen cac me mang the kham. •Neu
xay ra 6 giai clop sorn cha su phut tridn hop tir thi met phan co the se mang dot
bien lech bei.
+ Hau qua va y nghia cua lech bei :
• Lech bei lam mat can bang cUa he gen clan t6i giam sire song, gay chat,
giam kha nang sinh san. Tuy nhien met s6 dot bien lech bei c6 the song duoc
nhung thuOng mac benh him ngheo nhu hei chdrig Dao, Tocno,-Claiphento... or
ngtr6i. O thuc vat cling gap cac lech bei nhu 6 chi Ca, chi Lila.
• Lech bei cung cap nguydn lieu cho tien hoa va ellen gieng.
— Dot bi'6n da bei : c6 2 dang co ban :
13


+ Tu da bOi : la so tang mot s6 nguyen l in 1)0 NST don bOi ctia loai, bao
gom da bOi chart va da bOi le. Sir roi loan phan bao nguyen phan tren toart b0 130

NST hieing Nil se tao nen clang ta bOi (4n). N6u roi loan trong phan bao giam phan
tao nen giao tit. 2n, giao ti:r nay k6t hop vOi giao tir binh thaeing se tao nen clang tam
bOi (3n), ke't.hop giCra cac giao to 2n vai nhau tao non clang tir bOi (4n).
+ Di da bOi :
• Duoc hint) thanh do lai xa ket hop v6i da bOi hoa se tao nen co the lai song
nhi bOi co kha nang sinh san binh thueng (rich./ khi lai giCra cu cai va cal bap tao
ra F l c6 18 NST caa 2 loai, roi du6c luting bOi hod tao nen clang song nhi bOi
36 NST (18 NST cita cu cai va 18 NST caa cai hap).
• I lau qua va vai tre caa da bOi: Th da bOi co to bao to, co quan sinh da6ng,
sinh san 16n, trio d6i chat mash, ch6ng chiu t6t, coy nghia trong chon gi6ng.
Trong to nhion, da bOi phO hien 6 thuc vat, him gap 6 (king vat la mot hating tier
hoa city sinh gio'i.

B. He THONG CAU Hbl LUYeN TAP
I. cAu HO! TRAC NGHol
Khoanh troll chi? cai

shin g trong cac can sun .-

Cciu I. Mu di truye‘n lu nu7 ho ha vi

A. Dam bao gen ma hod daoc cac axit amin.
B. S6 luting ma dU dO ma hoa cac loaf axit amin.
C. Ch(rng minh duoc vai Ire truyOrt thOng tin di truyOn caa gen.
D. Mc dinh dtroc tinh along qttan glib gen va protein.
Cciu 2. Mci di truve‘n có tinh thooi Iwo hien

Hui ming :

A. MOt bO ba c6 the ma hoa nhiOu loai axit amin.

B. NhiOu 110 ba khac nhau ma hoa cang 1 loai axit amin.
C. MO bo ba ma hoa mot loai axit amin.
D. CO 3 bO ba ket thac khOng ma hod' axit amin.
Can 3. Diu kien c eirr va di; guy dinh tinh dcic tri(ng ye calu tnic hod hoc cna gen 10

A. S6 luting bon loai nucleatit trong gen.
B. KhCii luting phan tir cUa gen.
C. "Prat to phan b6 cac nucleOtit caa gen.
D. 'Ranh phan cac foal nuclOOtit cua gen.
14


Cciu 4. VUng gen ma thong tin di truyen duo• the hien trong

trier hoa hoc

(1;(1 protein lu :

A. Wing gen ma hoa.
C. Wing gen 1(6 thtic.

B. Viing gen khoi Ong;
D. Ca B va C deu thing.

Cciu 5. Gen c ail triic lu :
A. MO doan ctia phan tir ADN ma hoa 1 phan tit prOtein.
B. Wt doan dm phan tir ADN mang thOng tin ma hoa mot chuoi
pOlipept it hay ARN.
C. San phdm th6 c6 thong tin di truyen chtta dupe chinh sira.
D. MOt doan phan ADN co chile nang di truyen va bien di.

Can 6. Tn.' 4 loci inteleOtit A, T, G, X tao nen Indy bO ha ( .6 nglait nu7 hoa rae
axit amin ?

B. 61.
A. 64.
D. Chita xac dinh dupe.
C. 16.
Sir dung du kien sau de tra 161 to cau 7 den cau 12. M6t gen cau true ctia sinh
vat nhan scr c6 kh6i Itrqng phan tO' ctia yang phien ma la 9.105 dvC.
Can 7. Chii;‘r, dai (.4a dociti gen d vUng phien mit' la :
B. 4080A.
A. 5100A.
D. 3060A.
C. 2040A.
Can 8. Nen doan phien ma' (.6 A = 20% fill so- 11(971g lien ket hidro gi1ta roe rap
bazo nito tree (loan phien nurla

A. 3900.
C. 3600.

- B. 3000.
D. 3450.

Can 9. So- hiong chit ki .vo4n ruu noun rm7 hot; lea :
B. 100.
A. 150.
D. 250.
C. 300.
Cau 10. Doan ind hoa (.6 the m(7 hoa duo• sO luoig alit amin trong pilaf!

ti

protein duoe tone hop lu :

A. 500.
0.498.

B. 499.
D. 497.

Can 11. S6 prong dvit amin (.6 trong phan lit' protein Noun chmh duo• tong hop tit
(loan gen lu :
13.498.
A. 499.
D. 496.
C. 497.
15


Cciu 12. So lu'ong lien ket peptit co trong phan prOtein hoan chinh

tong

hop ta'docm gen lit :

A. 499.
B. 500.
C. 498.
D. 497.
Can 13. Ca che't O'ng hop ADN dijn ra theo nguyen tcic

A. KhuOn mau, bao•t6n. •
B. KhuOn mau, ban bao ton.
C. Nguyen tac b6 sung, bac) ton.
D. Nguyen tac khuOn mau, gian doan.
Can 14. U vi sink vat nhan so, enzim thao xocin phan ti' ADN ate tao ra Char cIii
Y la :

A. Ligaza.
C. Primezara.

B. Repliaza.
D. Amilaza.
Can 15. Enzint tong hop cac mach mai ADN con la
A. ADN pOlimeraza.
B. Transperaza.
C. Ligaza.
D. Giraza.
Can 16. Chien t Ohg .hop ciicr enZim ADN palimeraza tree phan th'ADN mai la :
A. Chieu 5' — 3'.

B. Chieu 3'— 5'.

C. Khi thi 5' — 3', khi MI 3' 5'.

D. Tuy thuOc vao don vi tit ban.

Cciu 17. Cac (loan Okazaki lora( tong hop tir mach mio cha ADN me ?
- A. Mach 3' — 5'.
B. Mach 5' — 3'.
C. Ca A \fa B deu

D. Tuy thuOc vao da'u trtic cita chac chit- Y .
Can 18. Vai tro ca ban cha enzim ADN polimeraal trong qua trinh

Whitt dot.

cha ADN lit

A. Mao xodn phan tir ADN.
B. Be gay cac lien kel hidrO.
C. Lap rap cac nucleOtit to do vao mach.
D.-Cung cap nang litong cho qua trinh king hap.
rat nhali sa, phan M'ADN mach vOng co nary don vi tai ban ?
A. MO don vi tat ban.
B. Hai don vi tai ban.
C. Nhieu don vi tai ban.
13. KhOng xac Binh duvc.

Can 19. d

16


Cdu 20. Phan tfi' ADN mach vong o sinh vat nhan so có may chac chid Y ?
B. Hai.
A. Met.
D. Nhieu chac chit Y.
C. BOn.
Cciu 21. Vai tro cfia qua trinh nhan doi ADN lu :
A. On dinh thong tin di truyen qua cac the" he.
B. Tao ra cac 'ADN con gi6ng ADN me.

C. Gill' duqc sn. on dinh cac ma di truyen.
D. San pham protein cunt con gi6ng b6 me.
Sii dung dit kien sau de tra lei tit cau 22 den cau 25. MOt doan phan tit ADN
me có chieu dai 0,408um có A = 20%. Khi tai ban 5. 01 lien tiep thi :
Cclu 22. S6- lfiong nucleotit moi loui moi trttOeng cdn sung cup lu :
A.

A = T = 480
G = X = 720

C.

A = T = 240
= X = 360

A = T = 720
G = X = 480
D.

A T = 360
{G = X = 240

Cciu 23. So- lien ket hidro hi pha huj; gat cac cap hazo' nito hd sung tren.cac phan
to ADN sinh ra (khong tinh tai cac lien ket hidro hi pha 1714 d cac down
m6i vai much khuon) lu :
B. 97620.
A. 96720.
D. 98940.
C. 99840.
Cdu 24. SO- lien kei photpho dieste can hinh thanh ld

B. 76768.
A. 74369.
D. 76800.
C. 74400.
Cciu 25. SO- lfiongchu ki man cfia down phan tfi' ADN
B. 240.
A. 120.
D. 140.
C. 180.
rnOt much a' phan ADN
Cau 26. Vi sao trong qua trinh tong hop ADN
dfiok tong hop lien rye, much con lui du'oc tong hop gian down ?
A. Do cau true cua phan tit ADN.
B. Do tinh chat hoat Ong cUa enzim ADN—aza.
C. Do mei trueng tObao khi tong hop.
D. CAA va B deu dUng.
2A- DTTHSTH

TAN TAO UNIVERSITY LIBRARY

17


Cciu 27. Su tong hop phan tt? ARN dien ra tren mach nao ctra gen c an trac ?
A. Mach c6 chieu 3' — 5'.
B. Mach c6 chieu 5° — 3'.
C. Khi thi mach 3' — 5' khi lai mach 5' — 3'.
D. Da phan la t6ng hop theo chieu 3' — 5', mot s6 It lai la mach 5' — 3'.
Cciu 28. Su' tong hop ARN có y nghia la
A. Tao thOng tin trifc tiep t6ng hop prOtein.

B. Co ham lacing ban phien ma thOng tin on dinh.
C. Dam bao thOng su6t vai tre thOng tin di truyen trong t6 bao.
D. DOng luc thfic ddy viec cung cap figuyen.lieu cac axit amin.
Cciu 29. Chien hoat dOng chitc ruing ina mARN thong tin la :
A. Chieu 5' — 3'.
B. Chieu 3' — 5'.
• C. Ca A va B den &Mg.
D. Khong xac dinh duqc vi con tuSi thuOc vao loai enzim.
Cart 30. BO ba ma" hoci nao sau day la bo ba kei thac tren phan til mARN ?
A. UGU.
B. UGA.
C. UAU.

D. UXA.

Cciu 31. Cac nucleOtit trong phan to ADN khac nhau chi yen boi thanh phcin nao
trong can true ?
A. Cac bazo nito.

B. Cac nhorn duOng.•
D. Kich thuOc phan

C. Vi tri nhorri photphat.
Cciu 32. Su khac nhau co ba'n
cac nucleotit trong phan tz' ADN va cac
ribonucleotit trong phan ARN la :
A. Cac bazo nito.

B. Call true cUa dueng.

C. Ket ca/u cua phan dr.

D. DO ben cau
Cciu 33. Dien kien ccin va du guy dinh tinh dcic trong ye mut can true hoa hoc
cac phan ARN la :
A. S6 10:mg ribOnucleOtit.
B. Thanh phan cac loai ribonucleOtit.
C. Trat to phan b6 cac ribOnucleOtit.
D. Ca A, B, C deu dung.
18

2B- DTTHSTH


Cciu 34. Nguyen tac bef sung &tor the' hien q cdu true cda loci ARN nao sau day ?
B. tARN.
A. mARN.
D. Ca A, B, C deu dung.
C. rARN.
Cciu 35. Vai fro co. ban cfia tARN la :
A. Mang cac axit amin dac trung.
B. Dua cac axit amin den not tang hop.
C. Doi ma di truyen theo nguyen tac 136' sung.
D. Ca A, B, C deu dung.
Cciu 36. Vai tro cc ban cuu rARN lu :
A. Ket hop vdri prOtein tao nen ribOx0m de dich ma.
B. Nban biet cac axit amin trong protein.
C. Tach 1)6 axit amin ma dau.
D. Ket thlic t6ng hop prOtein.
Cau 37. U loci sink vat nao sau dciy (.6 mARN .tho l'a mARN thanh thus có kich

thithe bang nhau ?
B. Sinh vat nhan so.
A. Sinh vat nhan thuc.
D. Ca A va.B deu dung.
C. KhOng xac dinh duoc.
Ulu 38.• Luc na0 cac gen trong operon Lac tong hop duqc cac loci protein ?
A. PrOtein tit ch6 a trang thai hoat Ong.
B. Protein dc ch6 o trang thai bat hoat.
C. Thi6u lactOzo trong rneii tru'ong.
D. PrOtein tic the khOng gan vOi chat cam Ling.
Cau 39. Protein ac che'bdt hout chi khi :
A. Duoc gan vOi chat cam ting inductor.
B. KhOng gan voi chal cam (mg inductor.
C. Cj cac gen cau true bi dOng khOng hoat Ong.
D. Lung protein trong to bac da duot tang hop du.
Cciu 40. Protein ice elle' &icy( hour hoa cid khi :
A. KhOng gan vai chat cam ting inductor.
B. Gan yeti chat cam mg inductor.
C. Lung protein san sinh tif gen cat' true chua du.
D. Cac gen cau true dang t6ng hop mARN.
19


Cciu 41. a sinh vat nhcin thkre, tin hien dieY hat hout dOng dal gen It
A. Nhirng phan tir do cac to bao biet hoa cao dO san sinh ra.
B. Doan tin hieu dieu hoa ton tai trong operon.
C. Doan promotor nam tru6c operator.
D. Ca A, B_va. C deu dung.
Cciu 42.

d cac sinh vat nhan thuc, Ida biet cart trUc cfia phan fa' mARN thanh thuc

do gen cart true tao ra thi c6 the suy ra du.qc trinh phan 136 eau cac
nucleotit cua gen khong ? Vi sao ?
A. Duqc, vi trinh to cua mARN MI-1g tuye'n tinh v6i gen.
B. KhOng, vi trinh tu.cUa mARN khOng tuye'n tinh voi gen.
C. Duqc, vi da duot chimg minh bang thuc nghiem mARN duqc tao ra tit
khuon mau gen.
D. Ca A va C deu dung.
Cau 43. Dar diem salt day It khong thing klai not v e ma di truyen ?
A. Cac 130 ba dOng nghia cho hau het cac axit amin.
B. Cac 130 ba th6ng nhaI cho loan b0 sinh gioi.
C. Duccc doc theo chieu 3' — 5' ke dr ma kh6i dau„
D. Co cac 1)0 ba m6 dau va k6t- thitc dich
Gnu 44. Plicit Neil new Sall day It khong clang khi not ye tARN ?
c6 1 b0 ba doi ma dac trong.
A. 'M6i" tARN
B. M6i tARN chi mang mot axit amin.
C.. Cac tARN chi khac nhau 6130 ba doi ma.
D. Co tARN van chuyen khOng mang axit amin nao.
the tong hop ADN 'ma
Cciu 45. Dieu gi du'o'c Watson —Cris' tien down trong
sun nay da" &far tlufc nghiem chink minh ?
A. Su t6ng hqp ADN din ra tren tUng sqi don cua phan tUADN.
B. Su tong hop ADN din ra theo nguyen tAc b6 sung.
C. Cac ADN t6ng hop duqc gi6ng hoar' toan-ADN me..
D. Su nhan doi ADN dien ra theo nguyen the ban bao ton.
Cciu 46. Phan tich thank phan hoa hoc caa gen tren tang mach din 141 sari pha'm
rnARN chfcc tong hop tren gen do có shill vat nhan sa thu du'o's kei qua
tilut sun :

20


7

A

G

X

T

Mach 1 cCia gen

19,1

26,0

31,0

23,9

0

Mach 2 dia gen

24,2

30,8

25,7

19,3

0

mARN

19,0

25,9

30,8

0

24,3

Much gen tong hop phan ni'mARN lir :
• B. Mach 2.
A. Mach 1.
D. Chua the xac dinh.
C. Co the ca. A va B.
Cciu 47. Mdt phon tARN co. 1)0 ,ha doi ma Ave se" ket cup vai bes) ha mu phien
tido 0-en phdn tii'mARN thOng tin ?
B. GXG.
A. UGG.
D. UGX.
C. AGG.

Ulu 48. a sinh vat !than thifc, phan dieu hod la sdn philm do cur re hew dd
du'ac bier hod sdn sinh ra de tac crOng len cac te"bdo dich de' dien hod cdc
gen c; do: Cat. phan to do la
A. PrOtein, enzim va cOenzim.
B. HoocmOn va cac nfian to tang trirOng.
C. Cac khang the, cac ion kim loai.
• D. Cac gen ngoai lai va cac phan tir dieu hoa.
cau 49. Mac do new sau day &rot. Adc nhdn do la diA hoa mac sau dich m.a d'
sinh vdt nhtin thyv ?
A. Cac gen tong hop ra cac loai san phdm ma t6 bao co nhu cau 16n dirge
nhac lai nhieu Fan.
B. Tru6c khi din ra dieu hoa, NST phai thdo xoan 6 doan ttrung (mg roi
enzim phien ma tumg tac yoi protein dieu hoa barn vao doan kh6i Tau.
C. Trong cling mot loai to bao, cac loai mARN có .th6i gian song khac
nhau, tire la co sir phan hod trong khau dich ma., ..
D. T6 bao co mot he thong enzim phan giai protein mot each co chon loc,
giup loai 136 protein ma t6 bac, khOng can am.
Cau 50. d sinh vdt nhan SO", khi có mut lactoza nhu' la chat cdm ang inductor thi
co frac dung gi ? vie thin den kei qud gi ?
A. Gay bat hoat protein ire ch6 va gen van hanh m6 ; phien ma, dich ma.
xa' y ra.
B. Gay bat hoat protein tic ch6, gen van. hanh (long ; ngirng phien ma,
dich ma.
21


C. Protein tic the hoat deng, gen van hanh m6 ; phien ma, dich ma xay ra.
D. PrOtein tic the hoat cleng, gen van hanh dong ; phien ma, dich ma
ngimg xay ra.
, •

Cau Si. d sinh vat nhan so', khi khong co mat lactOza trong moi twang thi :
B. Gen van hanh (long.
A. Gen van hanh m6.
C. TuS, timg trueng hop.
D. KhOng xac dinh &roc.
Cdu 52. Trong co' che. dien hot', hien hien eau gen a sinh vat nhan-so, vai tro cuu
gen dieu hoc? lir :
A. Noi tiep xtic vgi enzim ARN—aza.
B. Noi gan cua prOtein tic cite can tre hoat Ong cita enzim phien ma.
C. Mang thOng tin cho viec tong hop protein" tic the tac deng len vimg
khei deng.
D. Mang thong tin cho viec tong hqp protein tic the tac Ong len gen
van hanh.
Cciu 53. Bien di td hop khac vai dOt hien gen va dOt hien NST (ha yen lir :

A.6 su to hop vat chat di truyen vein cc-) cita b6 me.
B.6 nguen nguyen lieu so cal) cho tien hoa va chon gi6ng.
C..Xay ra ngau nhien rieng re 6 ding ca. the.
D. Co thd di truyen cho the he. sau.
Cau 54. Dung dOt hien nao sau day khong du'or rem nhu' la mot dung clOt hien
gen ehinh thong ?
A. NISt mot cap nucleOtit.
C. Them met cap nucleOtit.

B. Dao vi tri met cap nucleOtit.
D. Thay the met cap nucleetit.
Cciu 55. Loui elOt hien nao sau day killing di truyen du'o's cho doff sau hang sinh
sdn hurt tinh ?
A. Dot Nen giao tit.
C. DOt Nen tier' phOi.

B. Dot bien xerna.
.
D. Dot bien so Wong NST.
Cciu 56. Mii'e phdn awg cOa kiea gen truac moi twang co di truyen dive khOng ?
Vi sao ?
A. Di truyen dugc ; do kidu gen quy dinh.
B. KhOng di truyen dugc ; khOng do kieu gen quy dinh..
C. KhOng di truyen dugc ; chi là biduhien kidu hinh.
D. Di truyen dugc ; quyet dinh boi san phdrn protein tao ra.
22


Ciiu 57. Hie14 and tar dOng cad chop loc td nhien doi voi dOt bien gen xdy ra cha
yen d rink :
B. Protein. A. Kidu hinh.
D. ADN.
C. Kidu gen.
Cciu 58. Dieu. kieu nao sau day khOng phdi la clue hio clue trung cau thdong biers ?
B. CO tinh dOng boat. ,
A. Co Wong xac dinh.
D. Kh6ng di truyen duac.
C. CO Wen d6i nh6 6 be gen.
Carl 59. Tinh chat bien hien ilia dOt bien gen the hien hang kieu hinh lci :
B. CO
A. CO hai.
D. Ca A, B, C.
C. Trung anti.
Cciu 60. DOI- hien nao ddoi day gay nen benh hong cdu hinh liem o nguOi
B. nein met cap nucleOtit.

A. Thay th6 mot cap nucleOtit.
• D. Dao vi hi met cap nticleOtit.
C. Mgt mot cap nucleotit.
Cciu 61. Wm and caa dOt bien can true NST thd 21 d ngurYi la :
A. Kieu tam lech dai hurl NST gi6i tinh X.
B. Ton tai 6 dang the ba tao hOi chting Claiphento.
C. Khi mgt doan se gay ung dm' mail.
D. Dec nhat mang gen hoocm6n sink tru6ng.
Cau 62. Hien tdong mat thdi a r•uoi giain la do•kitfu dot bien nao gay ru vu xdy ru
ti- en NST nao
A. Mgt doan, tren NST X.
B. Chuyen doan, tren X hoac tren Y.
C. Lap doan, tren NST X.
D. Dao doan, tren NST X.
Cau 63. Phdn 16n dOt bien 111 nhien (.6 hai la do':
A. Da s6 dot bien là Fan.
B. Siic song cac the dOt bien kern.
C. Dot Nen pha v6 tinh hai hoa trong kieu gen.
D. Xugt hien tdri so kha cao.
Cciu 64. Tui suo phcin Ian clot hien gen la dot bien kin ?
A. Dot bien gen thu6ng la dOt bier' thuan..
B. Dot bien gen thu6nglà dot bien nghich.
C. Tac nhan gay dot bien thu6ng chi tac Ong den gen tr6i.
D. DOt bien gen thu6ng chu y6u la dOt bi6n thay th6 nucleOtit.
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Cciu 65. D6t hien gen to nguan nguyen lieu (.IM yeti cita. choir for trl nhien vi :
A. Dot bien gen la dOt bier' nhO It anh htrOng den sire sting.
B. it,bieu hien ra ngoai khi xuat hien.

C. Dai 130 phan la dOt bier' có
D. Ton tai ph6 bien qua cac the- he giao ph6i.
Cciu 66. Vai tro ciia qua trinh giao phoi vai tien hoa lu :
A. Phat tan dOt bier' trong qudn thd, trung hoa dOt bien có hai.
B. Duy tri cac dOt bien qua cac the he giao ph6i.
C. Phan hod kha nang thich nghi cua quan the giao ph6i.
D. Thay d6i gia tri thich irng cua cac loci qua giao ph6i.
Cdu 67. Tac nhan gay d6t bien tia UV tuo ra lien k et gi tren mot much do'n phan
tii ADN de tuo ra d6t bi ?
A. Dimetimin, thay the A=I' bang G—X.
B. Dimetimin, thay the G—X bang A—T.
C. PhOtphodieste, thay the G—X bang A—T.
D. Dimetimin, dao vi tri 1 cap nucleOtit.
Cau 68. D6t hien gen la :
A. Nhiing bi6n d6i trong cau triic gen, lien quan d6n mot hoac mot s6 cap
nucleOtit.
B. NM:Mg bi6n d6i trong au true ADN, lien quan d6n mot hoac mot s6
doan ADN.
C. Nhiing Nen d6i lon trong NST the hien tren cac dang mat doan, lap
doan, dao doan NST.
D. Nhang bien d6i thtrOng xuyen xay ra tren ca chieu dai phan tit* ADN.
Cau 69. M6t gen (.6 A = 450Nu, G = 1050Nu. Khi gen hi d6t hien thi A = 451Nu,
G = 1050Nu. Day la dung d6t bien :
B. Thay 1 nucleOtit.
•
A.. Them 1 nucleOtit.
D. KhOng xac dinh chive.
C. Dao vi trl I cap nucleOtit.
Ctiu 70. M6t gen co A. = 600Nu, G = 900Nu. Khi d6t bien gen lui (.6 A = 599Nu,
G = 901Nu. Day la dung d'Ot hien :

A. Thay the mot cap A—T bang mot cap G—X.
B. Thay the mot cap G—X bang mot cap A—T.
C. Mat mot cap A—T. •
D. Them mot cap G—X.
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