biotechnology and gene tech answers f215 (1)

8/21/2019 Biotechnology and Gene Tech Answers F215 (1)

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1. (i) plasmid cut by restriction enzyme;at specific sequence;same enzyme as used to cut (insulin) gene;sticky ends / described;ref. complementary sticky ends;ligase seals (sugar-phosphate) backbone / AW; ma !

(ii) credit any two from the following"

# antibiotic resistance (gene) introduced and sur$i$ors ha$e plasmid;

% fluorescent marker (gene) introduced and glo&ing bacteria ha$e plasmid;

' identify bacteria producing insulin using antibodies; %[6]

2. referring to pig insulin:ethical / religious reasons;incompatibility / lack of tolerance / immune response; oranot eactly the same as / less effecti$e than human insulin; ora

referring to human insulin from bacteria:

engineered insulin is cheaper; oragreater supply of engineered insulin; ora #

[1]

3. (i) (penicillin) secondary metabolite ;produced at start of / during stationary phase / end of gro&th phase ; Alogphase ref to production (at maimum) &hen kept short of nutrients/ nutrients depleting / factors limiting gro&th ;

continuous culture maintains in log / rapid gro&th phase ; % ma

(ii) to pro$ide respiratory substrate / energy ; Afor respiration

to maintain culture / keep culture ali$e / pre$ent (premature) death ofculture ;

(limited) maintains in stationary phase / pre$ents rapid gro&th ;

A* ; Rglucose as carbon source % ma[4]

The Henrietta Barnett School 1


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4. 1 genetic testing / screening;

2 for inherited disease / AW;

3 (test to see if) indi$idual is carrier;

4 premarital testing / predict if (potential) offspring may inherit the disease;

5 antenatal testing;6 ref to termination;

7 embryo selection (to ensure embryo healthy);Rselection of se

8 (test for genes that contribute to) diseases that de$elop later in life ;

9 those &ith genes gi$en ad$ice to limit effects / counselling;

10 faster / earlier diagnosis;

11 de$elop more effecti$e / efficient drugs (to combat disease) ;

12 drugs ha$e direct effect on genes / protein made from specific gene code;

13 gene therapy / correct the base sequence of faulty gene;14 economic implications / AW;

15 A*; e.g. ref. to method used / use of gene probes / biopsy

16 A*;allo&s targeting of drug treatment ! ma[4]

5. AA+,,, / adenine adenine thymine cytosine cytosine cytosine ; (first )[1]

6. can fi nitrogen;does not deplete soil nitrogen / impro$es nitrogen content of soil (o$er time);allo&s culti$ation of poor soil;reduces use of fertilisers;higher yield;A*; e.g. reduce contamination of en$ironment by fertilisersqualified cost ref.ref. leaching of nitrate % ma

[2]

7. (a) odd number of sets of chromosomes / AW ;

homologous pairs not formed ; Aref to difficulties in pairing

during meiosis ; allow point if reference made to causing problemsduring meiosis

does not form seeds ; ma %



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(b) ref to sterile conditions / aseptic techniques ;

(small) piece of plant tissue remo$ed ; Atake cuttings

ref to named tissue ; e.g. meristem aillary / (apical) buds

eplant ;

orleaf remo$ed ;

enzymes / cellulases / pectinases to remo$e cell &all ;

protoplasts formed ;

gro&th on nutrient medium ;

plant gro&th regulators / named gro&th regulator ; Rhormones

rooting ;

incubation in light ;

plantlets ;subdi$ide ;

handling medium / sterile soil ;

A* ;

A* ; e.g. remo$e &a from lea$es

callus culture / mass of undifferentiated cells forms

ref. auin to cytokinin ratio

urashige and koog ( 0 ) medium

further detail of culture method / aseptic technique ma 1

(c) max 4 for either

advantages

many plants ;

genetically identical ;

(so) all ha$e desired characteristics / genotypes / phenotypes ;

no need for (artificial) selection ;

can be obtained in short space of time / AW ;easy to transport / store ; Aref to space sa$ing

easy to genetically engineer ;

disease / $irus free ;

disadvantages

genetically identical qualified in terms of disad$antage ;

susceptible to disease ;

loss in genetic di$ersity (as cloned plants are gro&n eclusi$ely) ;

farmers ha$e to buy plants from suppliers / AW ;ref to economic problems for de$eloping countries ; e.g. start up costs

patented property ;



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A* ;

A* ; e.g. no quarantine required ref. to cost qualified not labour intensi$e (ad$antages)genetically unstable (disad$antage) ma 1

[12]



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8. (a) pro$ides oygen for aerobic respiration ;

any detail e.g. oidati$e phosphorylation ;

sterile to pre$ent contamination ;

mies fungus &ith substrate / pre$ents settling / bubbles help stirring / AW ; %

(b) (i) carbon 2 glucose / lactose ;

nitrogen 2 amino acids / nitrate ions / ammonium ions / yeast etract ;

A corn steep liquor for either but not both %

(ii) &ater is for cooling / remo$ing ecess heat ;

maintains constant / optimum temperature ;

respiration produces heat ;

&hich &ould denature enzymes / kill cells ;

heat also produced by stirrer / motor ; ma '(iii) &ill affect enzyme action / metabolic rate ; Adenature enzymes

addition of buffer / acid / alkali / base ; %

(c) (i) 3 hours ; #

(ii) Xincludes rapid / eponential / main gro&th phase ; ora

&hen primary products are made / penicillin is a secondarymetabolic product ;

ecess of nutrients in Xorpenicillin produced &hen nutrients

limited / depleted ; '

(d) filter (to remo$e fungus) ;

fungus &ashed (to remo$e penicillin) ;

continuous countercurrent / chemical etraction ;

concentration ;

addition of potassium ions ;

precipitate crystals / (potassium) salts ;

sol$ents used to purify penicillin ;A* ; e.g. dried some are chemically modified 33.14 pure ma '

(e) can genetically engineer microorganisms ;

ref to risk of infection ; e.g. ,56 &ith 78

a$oids problem &ith side effects / allergic effects ; Aref. toimmune response

large amount of product ;

gro& microorganisms in small area / $olume ; Aless space required

can be cultured any&here in &orld ;

ethical ad$antages qualified ;



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ref to cost qualified ; e.g. insulinuses cheaper feedstock (than forrearing pigs)

A* ;

A* ; e.g. high replication / gro&th rate

etraction of 78 from brains slo& process ma !

[20]

9. (a) (i) temperature ;

concentration of substrate / sugars /carbohydrates ; R$olumes / amounts

concentration of yeast ; R$olume / amount

p8 / carbon dioide concentration ;

oygen a$ailability ;

concentration of alcohol / ethanol / toic &aste ;

A* ; ma '

(ii) carbon dioide ; A,9%

#

(b) (i) one mark for slow, fast, slow / nothing

initial gas production slo& ref to time ;

rapid rate ref to time ;

little gas production ref to time ;ref to actual $olumes ;

any rate calculated ; ma !

(ii) ref to (aerobic / anaerobic) respiration ;

slow gas production

transport of glucose into yeast cells takes time ; Aabsorbed / takenup by yeast detail ; e.g. ref to carriers

rapid rate of respiration

high substrate concentration in yeast cells ;

rate slows

substrate runs out ;

or other factor(s) / named factor affect the rate ;

A* ; e.g. increase in number of yeast cells increases rate ofrespiration qualified ref to time taken for ad:ustment toconditions (in slo& production) ma !

(c) slower rate of respiration

enzymes(s) to metabolise / hydrolyse / digest / breakdo&n maltosenot present ;

genes s&itched on ;



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time for enzymes to be synthesised ;

ref to membrane transport / ease of passing through membrane ;

A* ; e.g. facilitated diffusion ma %[14]



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10. (i) fe&er genetically engineered mosquitoes pass parasites across midgut; Afigures

fe&er g e mosquitoes ha$e parasites in sali$ary glands ; Afigures

fe&er g e mosquitoes can infect (uninfected) mice ; Afigures

less good as vectors instead of all of first three points = only

use of comparati$e figures ; ma '

(ii) benefitone of follo&ing ;

reduce use of insecticide / drug

safer than insecticide / drug

A* ma #

ha!ardone of follo&ing ;

parasite may de$elop resistance

gene may pass to other species

A* ma #[5]

11. (i) adding / using &ater ;

breaking bond / ester bond (in molecule) ; Abreakdo&n into smallermolecules %

(ii) matri protects / stabilises (immobilised) enzyme / lipase ; allow once

so &ill function at optimal rate / more efficiently (than soluble) at highertemperature / !1 , ; Agreater acti$ity / AW

ref to soluble lipase begins to denature (reducing acti$ity) ; ora

continues to &ork at optimal rate / more efficiently at lo&er p8 ;

ref to presence of fatty acids changing p8 ;

ref to ionic bonds breaking (in soluble lipase) ; ora

A* ; e.g. ref to industrial uses ref to effect on < groups ma ![6]



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12. (i) attached to an insoluble material / AW ; #

(ii) (micro)encapsulation / (trapped) in alginate beads ;

adsorption / stuck onto e.g. collagen / clays / resin / (porous) glass ;

cross linkage or co$alent / chemical bonding to e.g. cellulose /collagen fibres ;

gel entrapment / trapped inside gel e.g. silica (lattice / matri) ;

partially permeable membrane (polymer) microspheres ; ma %

(iii) urine can be processed / no problem of remo$ing urine / AW ;

pure / drinkable / useable &ater produced ; A&ater recycled

space sa$ing / less &ater needs to be taken into space ;

payload limit / &eight reduction / AW ;

no need to take more enzymes into space / enzymes reusable ; Aenzymes

reco$erable

no problem in separating enzyme from products / product not contaminated ;

ref to longer shelf-life of enzyme ;

A* ; e.g. larger surface area of enzyme eposed more stable at etremes

ref to ease of use (of bioreactor) ma '[6]

13. (i) ref to r6=A / recombinant 6=A ;

restriction enzyme(s) ;

cut 6=A at specific site(s) ;

detail site(s) ;

ref to $iral 6=A and human 6=A / 6=A of gene ;

ref to sticky ends ;

complementary binding ;

detail of binding ; A > + / , > 7 / hydrogen bonds

ligase to seal ?nicks@ in (sugar-phosphate) backbone ; ma !

(ii) has effect &hen added to genome ;

not masked ;

no need to remo$e / inacti$ate recessi$e / mutant allele ; ma %[6]

14. (i) 6=A from t&o different sources ;

combined / :oined / AW ; %

(ii) restriction enzymes cut 6=A ;at specific sites ;

detail of sites ;



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may gi$e sticky ends ;

complementary sticky ends :oin ;

terminal transferase / enzyme adds sticky ends ;

ligase :oins gaps / nicks ; ma '[5]



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15. (a) 1 pre$ent self-pollination / un&anted pollination of flo&ers ;

2 detail of pre$ention ;

3 cross-pollinate t&o $arieties ; Acrossed / mated / hybridised

4 detail pollination ;

5 isolate plants / flo&ers ;6 collect seeds and so& ;

7 in high salt concentration ;

8 select plants &hich sur$i$e / can tolerate high concentration ;

9 and ha$e large tasty tomatoes ;

10 interbreed these plants ;

11 repeat selection ;

12 ref many generations ;

13 cross &ith $ariety &ith large tomatoes to impro$e size ;14 cross &ith $ariety &ith good fla$our to impro$e taste ;

15 ref backcrossing &ith original $ariety for salt tolerance ;

16 A* ;

17 A* ; ma

e.g. ref background genes / hybrid $igour / heritability /

effect on $igour / ref setting up pure-breeding initial lines

QWC legible text with acc!ate "#elli$g% #$ctati&$

a$' g!a((a! ; #

(b) (i) acti$e transport ;

(energy from) A+* / respiration ;

against concentration gradient ;

ref binding site for ion / AW ;

ref change of shape of protein ; ma '

(ii) 7B quick(er) / C slo&(er) ;

(tolerance) in one generation ($. many generations) ;

ref one gene / rest of genome unaltered ($. hybridisation) ;

background genes intact ($. need for backcrossing) ;

different $arieties engineered for different conditions ;

no problem re interbreeding ;

can select transporter system / AW / from another species/ named taon ;

can select transporter system / AW / for maimum efficiency ;

A* ; ma '

[15]



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16. aniety about (future) health / may not &ant to kno& / AW;many diseases &e can test for ha$e no treatments;discrimination by employers;discrimination by insurance companies / banks;reliability of tests in question;Afalse positi$e / negati$e resulteample of disease gi$en in contet;

cost to =8 / go$ernment;rich people can benefit / poor &ill not benefit;A*;;e.g. moral issues associated &ith embryo selection

eugenicsparents feelings to&ards childpresence of allele may not cause disease / ref to multifactorialdiseasesref to storage of data and freedom of information / in$asionof pri$acy / question of paternity

R?playing 7od@ / cloning ! ma[4]

17. (i) restriction (enzyme) / endonuclease; #

(ii) this may be answered in the context of inserting into a plasmid"

cut 6=A &ith restriction enzyme;ref to sticky ends;complementary;

base pairs / ,,, and 777 / , pairing &ith 7 / alternati$e;(6=A) ligase / ligation;ref to bonding / AW; e.g. hydrogenorphosphodiester / sugar-phosphate

A*; e.g. add sticky ends to blunt endscut both at the same place ' ma

(iii) codes for %protein / polypeptide / enzyme;Aref to protein synthesis / transcription / translation

(enzyme) catalyses / causes % condensation / formation of glycosidicbonds / reaction (bet&een %mannose / sugars); %

[6]



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18. cheaper;ref to compatibility / less chance of re:ection / fe&er side effects;stated ethical issue; e.g.don@t need to kill animals / remo$es religiousob:ectionsref to contamination / easier to purify / ref to disease;consistent quality;

more effecti$e (as human in origin);production le$el can meet demand / reliability of supply / faster production;ignoregreater production % ma

[2]

19. (a) (i) amylase ; #

(ii) glycosidic ; < glucosidic #

(iii) alpha / D ; #

(b) (i) encapsulation / trapped in alginate beads ;

adsorption orstuck onto collagen / clays / resins ;

cross linkage or co$alent / chemical bonding to cellulose (fibres) ;

gel entrapment / trapped in silica gel ;

partially permeable membrane microspheres ; ma %

(ii) does not mi &ith / does not contaminate / stays separate from theproduct ; ref to no / less / easier do&nstream processing ;

reco$erable / not lost during processing ;

reusable / cost effecti$e ;

matri stabilises / protects the enzyme ;

so acti$ity not affected by changes in temperature / p8 orrun ata high temperature / &ider range of p8 ;

longer use / shelf-life ;

so suitable for continuous culture / cost effecti$e / greater yield ;

A* ;

points can interchange if valid ma !

(c) not necessary to start &ith a pure enzyme ;

keeps the enzyme a&ay from oygen ;

more enzymes in$ol$ed ;

cell produces enzymes ;

A* ; e.g. enzyme(s) may be epensi$e / difficult to isolate

simultaneous processes can occur ma %[11]



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20. (a) (i) penicillin ; Aother named antibiotic #

(ii) (comple organic molecules) produced after / not produced duringthe (log / rapid / main) gro&th phase ;

not essential for normal cell gro&th / reproduction ; ma #

(iii) batch / fed batch ; #

nutrients only added at start ;

short / rapid gro&th phase ;

required product made during stationary phase / late in lifecycle ; ora

Rdeath phase

shortage / depletion of nutrients / named nutrients ;

cell di$ision / reproduction no longer occurring ;

ref to addition of glucose / lactose at inter$als

(to a$oid death of culture) ; ma %

(b) 1 air pressure &ill push the medium into the culture $essel ;

2 medium / nutrients added to the culture at a constant rate / AW ;

3 algae / cells / #hlorella remo$ed / har$ested from the sample port ;

4 at the same rate as / to match the nutrients added ;

5 so $olume in fermenter remains constant ;

6 remo$al of &aste / toic products ;

7 that could affect gro&th / reproduction ;8 (cells kept in) eponential / log / rapid / main gro&th phase ;

9 algae are photosynthetic ;

10 light energy required ;

11 ref to use of fluorescent light to a$oid o$erheating ;

12 ref to monitoring temperature ;

13 ref to optimum conditions ; A?conditions for maimum gro&th@

14 air bubbles to mi culture &ith nutrients / AW ;

15 air bubbles to allo& algae to get sufficient light ;16 air bubbles pro$ide oygen for (aerobic) respiration ;

17 and ,9%for photosynthesis ;

18 air flo&ing into the culture $essel flo&s out through an outflo& tube ;

19 pre$enting build-up of pressure ;

20 A* ; e.g. sampling to check for mass of #hlorella ma



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(c)

factorstalen$ironmengcontrollin

ofdifficultytorefformarkone

;p8constantagmaintainindifficulty

;emperatureconstant tagmaintainindifficulty

heating / cooling qualified ;

foaming ;

blocking of inlet / outlet tubes ;

difficulties &ith miing / stirring ;

contamination / keeping it sterile ;

conditions need to be continuously monitored ;

nutrient requirements may change ;

A* ;

A* ; e.g. algal gro&th on glass

difficulties in pro$iding sufficient light

errors lead to loss of se$eral days production of #hlorella ma ![15]

21. (a) plasmid $%& protein

nucleotides / sugar E phosphate E base ; amino acids ;

! different subunits ; %F different subunits ;

phosphodiester bonds ; Aphosphoester peptide bonds / polypeptide ;contains * ; contains / disulphide bonds ;

double-stranded / double heli ; may ha$e !G structure ;

circular ; ref to %G / 'G structure / AW ;

A* ; e.g. role of 8 bonds ' ma

(b) (i) stimulates immune response / production of antibodies / + or C cells ; #

(ii) stimulate cell-mediated immunity / + cells ;

antigen remains in body longer / continuously produced ;antigens in blood only stimulate humoral immune system / C cells ;

antigens (in blood) lost in urine / broken do&n in li$er ;

ref to 8, ; # ma

(c) (i) binds


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A* ; cheaper / reduces number of $accinations % ma

(iii) 7olgi modifies protein / polypeptide / AW ;

forms glycoproteins / add sugars orcarbohydrate ;

7olgi forms $esicles ;

incorporated into cell membrane ; Reocytosis

A* ; % ma

(d) cells that take up $%& vaccine might

1 function less &ell ;

2 be killed by immune system / trigger auto-immune response ;

3 ha$e genes disrupted / mutation ;

4 ne& gene might be inherited / AW ;

5 plasmid could enter bacteria ;

6 superbug / create ne& disease / AW ;

7 effects unkno&n / ne& technology / no human trials ;

8 A* ; ref ethics ref irre$ersible ' ma[14]

22. increase in use of 7 crop / 7B crop / Ct cotton ;

no / less insecticide needed ;

reduced number of cases of pesticide poisoning ;

ref to figures (e.g. by !.!) ;

reduced cost (insecticide) ;

ref to figures (e.g. by F.% HI kg-#

/ J #.') ;

ref to limitations of sur$ey ;

A* ;

Are$erse arguments ma ![4]

23. (a) (i) gradual process / AW ;

to impro$e traits ;

to achie$e homozygosity / AW ;

best in each generation interbred ;

ref to artificial selection ;

ref to se$eral traits in$ol$ed / may be additi$e / polygenic ; ma %

(ii) ref to mitosis ;

chromosomes replicated ;

failure of spindle / cell di$ision ; ma %



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colchicine / other method ;

(iii) self-pollination pre$ented ;

pollination by foreign pollen pre$ented ;

pollen transfer ;

practical detail ; ma %

(i$) 'n ;

meiosis fails ;

ref to synapsis / homologous pairs ; ma %



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(b) (i) sterile eplant ;

sterile nutrient medium ;

ref to plant gro&th regulators ;

callus ;

subdi$ided ;medium &ith different plant gro&th regulators ;

plantlets / embryoids ;

hardening medium / sterile soil ;

A* ; e.g. appropriate plant gro&th regulators ma 1

(ii) callus can be di$ided ;

large numbers of identical plants ; Aclone

in short time ;

bulk up sterile hybrid ;bulk up master hybrid lines ;

no need for making more !n ; ma %[15]

24. (i) type of starch ;

concentration of starch / suspension ;

$olume of starch / suspension ; Ramount

ref to flo& rate ;

size of beads ; Anumber / mass / $olume of beads in column Ramounttemperature ;

length / diameter of column ;

yeast concentration ;

p8 ;

A* ; e.g. age of culture ' ma

(ii) add Cenedict@s (reagent) and boil / heat ; A,u9!in alkaline solution

different densities / colours (of precipitates) formed ; Aturbidities

use of a colorimeter in correct contet ;

Afiltering and &eighing precipitate

)R

use of ,linisti / 6iasti (strips) ;

different colours obtained ;

colour compared to chart ;

accept other valid methods e"g" reference to use of biosensors % ma



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(iii) agree

not all yeast cells successfully entrapped / AW ;

(in product) yeast cells respiring / metabolising / using sugar as anenergy source ;

(so) lo&er le$els of sugar (in product) ;

not agree

yeast cells entrapped (in beads) / immobilised so product not contaminated/ yeast not present to affect product ;

yeast cells unable to pass through glass &ool / filter ;

only $ery lo& numbers of yeast cells (so unlikely to ha$e great effect) ; % ma[7]

25. any three acceptable e"g"disease / $irus free ;

genetically identical / clone ;

maintain fa$ourable characteristics / ad$antageous phenotypes ;

faster method ;

produces many plants ;

allo&s long-term storage of plant tissue ;

easily genetically manipulated / eample of genetic manipulation ;

easier echange bet&een countries as no quarantine ;enables optimal production of useful secondary products (e.g. codeinefrom poppy) ;

no eternal en$ironmental influences ;

no influence of seasonal $ariation ;

A* ; e.g. use for sterile / infertile plants

A* ; named eample of ad$antageous phenotype e.g. gro& more $igorously

use for rare or endangered plants

rele$ant eample of genetic manipulation ' ma[3]



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26. answers referring to insulin production can also be credited in mp ',(,4

1 )scherichia coli; A)" coli

genetic engineering ' ma

2 amino acid sequence (of 878) kno&n / analysed ;

3 gene coding for 878 synthesised ;4 using triplet code / genetic code ;

*+

5 m


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27. (a) r6=A > 6=A from t&o sources ;

both 6=As cut &ith restriction enzyme / named restriction enzyme ;

gi$ing sticky ends ;

or gi$ing blunt ends to &hich sticky ends added ;

complementary binding of sticky ends ;8 bonds / e.g. A to + / e.g. , to 7 ;

nicks in (sugar-phosphate) backbone sealed by ligase ; ' ma

(b) percentage / proportion of muscle fibres &ith central nuclei / dying muscle

fibres increases in control &ith time ;

percentage / proportion of muscle fibres &ith central nuclei / dying musclefibres reduced by treatment ;

ref to comparati$e figures &ith percentages and day ; '



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(c) advantages

1 can identify presence of disorder ;

2 remo$es uncertainty ;

3 allo&s early treatment ;

4 &hich may impro$e life epectancy / quality of life ; Aa$oidunncessary suffering

5 allo&s informed choice about ha$ing children / planning healthyfamily ;

6 allo&s KL and embryo screening / preimplantation geneticdiagnosis (*76) ;

7 allo&s fetal testing and termination ;

8 choice re donation / adoption ;

9 A* ; e.g. detail of donation" AK(6) / egg donation / embryodonation

(axi(( 5 &$ a'*a$tage"

disadvantages

10 false positi$es / negati$es ;

11 may not be test for all mutations ;

12 only small number tests a$ailable / not a$ailable for all conditions ;

13 simple presence may not result in condition ;

14 confirmed presence gi$es stress / fear ;

15 problem re telling / testing rest of family ;

16 discrimination by employers / insurers ;

17 ethics of termination ;

18 A* ; e.g. detail of problem of test risk of test procedurediagnosis and elimination rather than treatment increasein intolerance / discrimination of disabled ?designer@

problem (axi(( 5 &$ 'i"a'*a$tage"

ma

QWC clea! well &!ga$i"e' "i$g "#eciali"t te!("; #

must include both advantages and disadvantages and two terms

such as

life epectancy quality of life

KL *76 *78 AK(6)

amniocentesis

, karyotype

false positi$e false negati$e[15]



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28. award marks if diagram clearly annotated

reser$oir for storage of nutrients ;

ref to method for addition of nutrients and remo$al of &aste / products ;

Asubstrate

ref to more detail of nutrient addition / product remo$al at a constant rate /continually / throughout fermentation period ;

idea of rate of product remo$al equal to addition of nutrients ;

Akeep $olume constant

use of probes / sensors / monitors ; Athermometer (for temperature)

(to monitor) any t&o of temperature / p8 / oygen le$els ;

method to maintain p8 e.g. use of buffers tube to add acid / alkali ;

addition of antifoam ;

ref. to need to maintain sterility (to a$oid contamination) ;

method to maintain constant temperature e.g. (thermostatically-controlled) &aterbath cooling :acket ; Rheat echanger

A* ; e.g. use of stirrer method to a$oid clumping of cells / blocking of inlet oroutlet pipe(s) ! ma

[4]

29. (a) a$oid attracting a mate of a different species ; ora

ensure reproducti$e isolation ; # ma

(b) (i) diffusion ; #

(ii) so that they do not recei$e oygen constantly ;

there are mitochondria bet&een them and the cell surface ; # ma

(c) mitochondria / aerobic respiration / oidati$e phosphorylation inhibitedonly briefly ;

oygen concentration decreases again ;

pre$enting action of luciferase / production of light ;

each flash short ; orae.g. so not continuously lit

A* ; % ma

(d) acti$e transport ; Ae.g. =aE/M

Epump

protein synthesis ;

synthesis of named substance ;

mo$ement of organelles ;

phosphorylation of glucose ;

A* ; ; ; e.g. transcription translation anabolic reaction



25/38

Rrespiration 6=A replication chromosome mo$ement mitosis ' ma



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(e) cells / membranes damaged / disrupted ;

nitrous oide released ;

mitochondria stop using oygen ;

oygen allo&s light production / reaches light-producing organelles ;

in unlimited quantities / continuously so light is brighter ;respiration / oidati$e phosphorylation ceases ;

no more A+* / =A68%;

luciferin synthesis / regeneration stops ;

A* ; ' ma

(f) li$e bacteria respire / produce A+* ; ora #

(g) m


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31. (a) (i) # mutation ;% random / spontaneous / chance / pre-eisting ;' natural selection ;! drug / insecticide is selecti$e agent / selecti$e pressure ;1 resistants ha$e selecti$e ad$antage ; resistants sur$i$e / susceptibles die ;

N pass allele / mutation to offspring ; Rgene / resistance allele frequency increases ;3 rapid because multiplicati$e phase / short generation time / large#F numbers offspring / many breeding sites ; ma 1

(ii) lasmodium inside li$er cell / red blood cell ;antibodies cannot reach target / cannot be detected by immune system ;large genome ;antigenic $ariation / AW ;$ariation from meiosis ;detail ; e.g. independent assortment / crossing o$er

parasite s&itches bet&een different $ersions of proteins ;ref var gene ; ma '

(b) (i) marks in pairs - one pair onlymutation ; &ith lack of production ;

examples

in, promoter / on switch . so not transcribed .

to give premature stop codon . so, no useful / shortened, product .

deletion . with loss of allele / different product .

frameshift . so, different / no useful, m+%& / product .

in initiation codon . so m+%& not translated .& mutation . & lack of production; ma %

(ii) marks in pairs - one pair only

no membrane receptor / AW ; so no binding / internalisation ;no channel / carrier / pump ; so lack of essential nutrient / ion ;do not multiply in li$er ; so not a$ailable to infect red blood cells ;A* protein ; problem ; ma %



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(c) #FF4 protection &ith % boosters ;irrespecti$e of dosage ;NF4 &ith # booster ;no e$idence &ith 1F FFF &hether &orks &ith one booster ;ref to memory cells ;needs large numbers of parasite / ref #F FFF ' ;

safe / &ill not cause disease / does not kill mice ;might mutate back to &ild type ;can infect li$er cells e$en if no further de$elopment ;may need drug to remo$e from li$er ;data relates only to mice / may not be applicable to humans ;A* ; e.g. no data comparing results &ith standard antigenic (AW)

$accine ma '[15]

32. (a) (i) t&o recessi$e alleles/homozygous recessi$e/t&o of allele %;

no normal dominant/allele #;homozygous same allele as affected child; %

(ii) deletion remo$es base pairs;shorter/lighter pieces of 6=A mo$e further in electrophoresis;to&ards anode;so allele % shorter/lighter than allele #; ma '

(b) F.%1/%14/# in !; #[6]

33. (a) m


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(iii) eplant of meristematic / cambium / totipotent / pluripotent cells/ tissue ;

eplant (surface) sterilised / sterile nutrient ;

appropriate hormone to stimulate mitosis / di$ision ;

callus formed ;

subdi$ided ;

appropriate hormone to stimulate differentiation ;

plantlet formed ;

hardening medium / sterile soil ! ma

(i$) genetically identical ;

genotype does not affect result ;

easily genetically engineered ;

plants deri$ed from it identically genetically engineered / AW ;

large numbers easily obtained ;

early stages compact ; ' ma

so easily kept in identical conditions ;[15]

34. # restriction enzyme to cut gene from genome ;

% and plasmid / artificial chromosome / 6=A of $ector ;' same restriction enzyme ;! if cut &ith sticky ends then :oin ;1 if cut &ith blunt ends then sticky ends / nucleotides added ; Rbases &ith , bases one end and 7 bases other ;N requires terminal transferase ; (6=A) ligase needed to seal nicks in 6=A backbone ;3 ref to :oin phosphate - sugar / adds phosphate ;#F 6=A may be produced by re$erse transcriptase ;## from m


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[9]

35. (i) ! - base pairs ;palindromic / AW ;

specific sequence ; ma %

(ii) yes same sticky ends / sticky ends sho&n ; 7A+, / ,+A7complementary (bases) ;hydrogen bond ;A &ith + ;, &ith 7 ; ma '

(iii) t&o correct cuts ;G| A T T C A G A A T T T C G| A A T C

C T A A |G T C T T A A A G C T T A |G #[6]

36. (i) adding / using &ater to break bond / ester bond (in molecule);Abreakdo&n into smaller molecules #

(ii) matri protects / stabilises enzyme / lipase;

functions at optimal rate / more efficiently at higher temperature / !1 ,;Agreater activity / &3

ref. to soluble lipase begins to denature (reducing acti$ity); ora

functions at optimal rate / more efficiently at lo&er p8;ref. to presence of fatty acids changing p8;ref. to ionic bonds breaking (in soluble lipase) ; ora

A* ; e.g. ref to industrial usesref to effect on < groups ma !

[5]



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37. (a) 1 gene bank ;

2 ref to &ild type ;

3 maintain genetic di$ersity ;

4 ref to loss of alleles / genetic erosion ;

5 may ha$e appropriate trait for breeding ;6 for future use ;

7 requirements of breeders change ;

8 in case climate change / different conditions ;

9 ref to temperature / global &arming ;

10 ref to p8 tolerance / acid rain ;

11 as yet unkno&n traits may be useful ;

12 in case other named change ;

13 may lose trait if interbred ;14 may form part of food &eb / community ;

15 that cannot be replaced ;

16 adapted for habitat / niche ;

17 hybrids less &ell adapted ;

18 ref to etinction ;

19 A* ; e.g. need to maintain population for leisure fishing

20 A* ; ma

QWC legible text with acc!ate "#elli$g% #$ctati&$ a$'g!a((a!; #

(b) (i) enzyme from bacterium ;

break do&n 6=A of in$ading (bacterio)phages ;

ref to specific site of 6=A ;

detail of site (! - bp / palindromic) ;

cut 6=A ;

lea$ing blunt ends ;

or sticky ends ; ' ma

(ii) crucian carp# (thick) band in correct position (see diagram) ;

hybrid goldfish x common carp '(thin) bands in correct position ;

hybrid common carp x crucian carp '(thin) bands in correct position ; '

g o l d f i s h c o m m o n c a r p c r u c i a n c a r p h y b r i dg o l d f i s h x

c r u c i a n c a r p

h y b r i dg o l d f i s h x

c o m m o n c a r p

h y b r i dc o m m o n c a r p x

c r u c i a n c a r p

[15]



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38. tissue

# meristematic ;% undifferentiated / totipotent / able to de$elop into any cell type /

unspecialised ;' (cells) can still di$ide / undergo mitosis ;! $irus free ; max '

sterilising agent1 aseptic technique ; pre$ent gro&th of / contamination by bacteria / fungi ;N could o$er&helm / gro& faster than / compete &ith plant tissue ;

AAW max '

cytokinins, auxins

plant gro&th !eglat&! , #!&(&te! , h&!(&$e;3 cytokinins stimulate shoot / stem gro&th / many branches ;#F auins stimulate gro&th of root / root hairs ; max '

magnesium, nitrate ions, sucrose## magnesium for chlorophyll / photosynthesis ;#% nitrate (ions) needed for protein / enzyme / chlorophyll / named chemical ;#' sucrose con$erted to glucose / fructose / monosaccharide ;#! used in respiration / release energy ; max (

#1 A* ; e.g. further detail e.g. cytokinins stimulate cell di$isionno $ascular tissue therefore disease free ma

QWC clea! well &!ga$i"e' "i$g "#eciali"t te!("; #

award 23# mark if three of the following terms are given in correct

contextmeristematicundifferentiatedtotipotentmitosisasepticcontaminationregulator

promoterhormonechlorophyll

photosynthesis

respiration[7]

39. (a) (i) co& supero$ulated ;treated &ith hormone / L8 / named proprietary brand ;&ashed out of o$iduct (Auterus) / collected from o$ary ;detail &ashing ;detail collection ; ma '

(ii) ref to mitochondrial 6=A ;detail ; e.g. circular / self-replicatingmitochondria in cytoplasts fused &ith darted buffalo cell ; Aorganelle



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embryo has miture of buffalo and co& mitochondria ;nuclear / chromosomal 6=A is buffalo ;ref to bacterial contamination ; ma %

(iii) for correct phase of cycle ;ref to synchronisation ;

to prepare uterus for (implantation of) embryo ;ref to increased thickness of uterine lining ;ref to increased $ascularisation of uterine lining ; ma '

(b) increases rate of reproduction ;does not require species@ eggs ;so does not require fertile female ;does not require female for pregnancy / uses surrogate ;female not put at risk in tra$el / mating / pregnancy ;successfully formed embryo can be subdi$ided / cloned ;can use adult cells from all eisting animals to maintain di$ersity ; ma !

(c) sperm bank ;oocytes / eggs ; gametes5 > # mark onlyembryos ;tissue ;zoo / reser$e / game park ; ma '

[15]

40. max 7 for the process of genetic engineeringmax 2 for the advantages

1 identify / find gene (for insulin) / length of 6=A coding for insulin;

2 obtain / isolate / etractgene / length of 6=A (for insulin);obtain / isolate / etractm


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6 ref to complementary ends / sticky ends / described;

7 insert gene / AW into plasmid;

8 recombinant 6=A;

9 plasmid uptake by bacteria;

10 identify those bacteria that ha$e taken up the plasmid;11 pro$ide &ith ra& materials / nutrients;

12 fermenter / bioreactor;

13 bacteria produce insulin;

14 etract and purify / do&nstream processing;

15 A*;e.g.. detail of uptake by bacteriamethod of identifying those that took up plasmid*,


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complementary binding;8-bonds bet&een bases;A to + and , to 7;nicks in sugar-phosphate backbone sealed/AW;

by ligase; ma ![7]

43. (i) indicates the range of results;on either side of the mean;indicates $ariability/(standard) de$iation/(standard) error;indicates if data sets significantly different; % ma

(ii) no/small increase/figs. quoted;lag phase;ad:ust to conditions/detail of ad:ustment;

produce enzymes;A*; % ma

(iii) more rapid gro&th in non-deficient cells/ora;figures in support from both aes of graph;lo& ribose in 7*6 deficient cells/ora;less a$ailable to parasites/lasmodium;less production of


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45. benefits

a$oids in:ections / pain of in:ections / children@s fear of in:ections ;mimics normal pancreatic beha$iour ;more stable homeostasis / reduced highs and lo&s in blood sugar ;less chance hypoglycaemia / hyperglycaemia ;less restriction on lifestyle ;

no need to measure blood sugar ;A* ; max (

problems

re:ection ;cells could lodge else&here ;may take longer to act ;A* ; e.g. rat data may not be applicable to humans

transgene may ha$e unforeseen effect max ( ma ![4]

46. humans are eukaryotes /)scherichia coli is a prokaryote ;

humans / eukaryotes have 7accept ora8

larger proteins / genes ;introns ;?:unk@ 6=A / non-coding 6=A ;repeating sequences ;centromeres / telomeres ;fossil genes ;

)" coli cell much smaller ; oraselection for less &aste of space / more compact genome ; % ma

[2]

47. insulin is polypeptide / protein ;(promoter) s&itches on transcription or makes gene produce m


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48. meristematic/pluripotent/totipotent/cambial/undifferentiated tissue;sterile conditions;nutrient medium to encourage di$ision/mitosis;

produces callus;subdi$ided;different (nutrient) medium to encourage differentiation;

detail of either medium; e.g. named nutrient or plant growth substancegro&s to plantlet;hardening medium/sterile soil; ma 1

[5]

biotechnology and gene tech answers f215 (1)

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