1-1. GCE Biology Marking Scheme (Summer 2007)

8/12/2019 1-1. GCE Biology Marking Scheme (Summer 2007)

1/29

MS3 WELSH JOINT EDUCATION COMMITTEE3.00 CYD-BWYLLGOR ADDYSG CYMRU

General Certificate of E!cation T"#t"#$rif A"#$ G"ffreinol

Advanced Subsidiary/Advanced Uwch Gyfrannol/Uwch

MAR%ING SCHEMES

SUMMER 2007

BIOLOGY


2/29

INTRODUCTION

The marking schemes which follow were those used by the WJEC for the Summer 2007

examination in CE !"#$#%& They were finalised after detailed discussion at examiners'

conferences by all the examiners in(ol(ed in the assessment& The conferences were held

shortly after the )a)ers were taken so that reference could be made to the full range of

candidates' res)onses* with )hotoco)ied scri)ts forming the basis of discussion& The aim of

the conferences was to ensure that the marking schemes were inter)reted and a))lied in the

same way by all examiners&

"t is ho)ed that this information will be of assistance to centres but it is recognised at the

same time that* without the benefit of )artici)ation in the examiners' conferences* teachers

may ha(e different (iews on certain matters of detail or inter)retation&

The WJEC regrets that it cannot enter into any discussion or corres)ondence about these

marking schemes&


3/29

AS MODULE B!

&!e#tion An#'er#(E)*lanator" Note# Mar+#

A,ailale

./ amylose+ ,7-

al)ha.+

glycosidic+

water./2#+

beta.+

hydrogen./+

microfibrils+

0/ a1 + ,3-

4+

C+

+/+

b1 50 60+ 1

2 8+ 1

,2-

c1 )roduction of ha)loid gametes+

not9 half :;. half number of chromosomes1

so di)loid number regained in


4/29


A,ailale

4/ a1 i1 )rotein+ ,-

ii1 correct )art labelled.circled+ ,-

iii1 com)lementary sha)e to glucose. similar sha)e to

substrate and acti(e site+

substrate.glucose will fit into.binds with acti(e site1.

en


5/29


A,ailale

5/ a1 cell wall ?+ ,5-

(acuole ? ?+

nuc mem ? +

chloro)lasts ? ?+

mesosomes ? ?+

mitochondria ? +

b1 i1 collection.number.many similar cells+ ,2-

working together.carrying out a function+

ii1 yes because many cells+ =ax ,2-

identical in structure+

working together to mo(e.raise forearm+

no because other tissues.blood (essels.ner(es. connecti(etissue )resent+

therefore is an organ+

Total 1.23

6/ a1 i1 cyto)lasm.rough endo)lasmic reticulum+ ,-

ii1 ribosome+ ,6-

)rotein+

not9 amino acid1

ribosomal.r@:;+

iii1 transfer.t@:;+

messenger.m@:;+ ,2-

b1 i1 )e)tide bond formed+ =ax ,6-

amine grou) linked to carboxyl grou)+

molecule of water eliminated+

condensation reaction+

)oints two and three can be shown on labelled diagram1

ii1 ;TA.en


6/29


A,ailale

7/ a1 :;. )lasmid cut o)en+ =ax ,8-

at certain base seBuences+

generating blunt.sticky ends+

use of restriction endonuclease1. en


7/29


A,ailale

9/ b1 ; diffusion+ ,0-

! high to low concentration.down a conc& gradient+

C )assi(e )rocess.no energy.;TA in(ol(ed+

facilitated diffusion+

E reBuires use of carrier.channel )rotein.molecule+

not9 intrinsic1

4 osmosis

mo(ement of water from high to low water )otential+

not9 water concentration1

/ acti(e trans)ort+

" ;TA de)endent+

J against.u) a concentration gradient+

D )rotein carriers in membrane reBuired+

$ endo.exocytosis.bulk trans)ort+= acti(e.energy ;TA de)endent )rocess+

: )inocytosis liBuid.)hagocytosis solid+

# in(ol(es breakage of membrane.in(agination+

not9 )inching off1

3


8/29

AS MODULE B2


A,ailale

./ a1 ?ylem

b1 =ass flow hy)othesis

c1 :itrates not9 nitrogen.formula1

d1 Counterflow.countercurrent

e1 Tissue fluid Total 6

0/ a1 i1 Aotometer

ii1 rate of1 water u)take by the shoot.(olume of water taken

u)

iii1 mo(ement of bubble indicates (olume of water taken u)

by the shoot1

b1 i1 cut shoot under water+

kee) lea(es dry+

set u) a))aratus under water.full of water

make sure >oints are airtight =ax& 2

ii1 to return bubble to


9/29


A,ailale

4/ a1 ; :itrogen fixation

! ecay.)utrefaction.decom)osition

C :itrification

Aenalty if bacteria mentioned1

b1 Stimulates )lant growth.algal bloom+

Which then die )lus the reason lack of light.nutrient de)letion1+

ecom)osition by bacteria+

Which increase in number+

#2 le(el decreases because #2 used by bacteria.higher

!#.res)iration+

eath of fish.in(ertebrates in context of )re(ious )oint1

=ax& 8

Total 9

7


10/29


A,ailale

5/ a1 i1 Symmetrical and correct way u)

$abels correct using names in table

Correct )ro)ortions

ii1 not all of organism eaten+

dead organisms not eaten+

loss of undigested material+

loss of C#2.res)iration.loss of heat+

$oss as urine.urea.excretion =ax& 2

b1 ead organisms may not be collected.only li(ing organisms

collected+

@oots.)art of organisms not collected+

:ot re)resentati(e areas sam)les+

Time of collection.seasonal (ariation+

ariable water content unless dried.dry biomass+

;nimals may be at more than one tro)hic le(el& =ax& 2

c1 @eflected+

$ight )asses through leaf.does not get absorbed by a chloro)last+

Con(erted to heat energy+

Some wa(elengths not absorbed by )lant )igments.eB&

not9 ref& to short wa(elengths+ not all hits the )lant1

=ax& 2

Total :

F


11/29


A,ailale

6/Inspiration Expiration

External intercostal

Muscles

Contracted @elaxed

Movement of ribcage G) and outwards own and inwards

diaphragm Contracts flattens1 @elaxes dome sha)ed1

Volume of thorax "ncreases.high ecreases.less

Pressure in thorax ecreases.less "ncreases.high

Direction of movement of

air

"n to lungs1 #ut of lungs1

#ne mark )er row& 5

b1 i1 ; H !

800 x 81 x 6 H18*F00 c;3

ii1 C H

000 x 01 x 6 I 160*000 c;3

No !nit# < . ;ar+ onl" if ot= an#'er# correct/

c1 "ncreases number of breaths )er minute.unit time in %&

"ncreased (olume of each breath in %

;ny use of figures

e&g& "ncrease in breaths from 8 to 0 in 20 secs1.eB in %

"ncrease in (olume from 800 to 000cm6in %

3 secs )er breath in ?* 2 secs )er breath in %com)arison reBuired1

d1 ol breathed in.out )er breath would be less

Time taken for each breath would be longer =ax&

Total .0


12/29


A,ailale

7/ a1 i1 ays 23 H 60

ii1 "ncrease in.high )redator numbers+

"ncreased )redation by higher )redator )o)ulation1

not9 ref& to carrying ca)acity1

b1 i1 ecrease due to lack of )rey

not9 food1

ii1 "ncrease1 due to lack of )redators

c1 i1 ;dd more )redatory mites at inter(als1

ii1 =aintain Aredator numbers or descri)tion linked marks1

d1 S)ecific to one )est1+

$ong term+

oes not de(elo) resistance+

:o en(ironmental damage.ref& to insecticide damage.no

bioaccumulation&

not9 not using harmful chemicals1

=ax&

Total 9

0


13/29


A,ailale

9/ a1 ; ;granulocyte.lym)hocyte.monocyte

! ranulocyte.)hagocyte.neutro)hil

4or A an Bif W!C's.$eucocytes #:E =;@D #:$%

C Erythrocytes.@ed cor)uscles.red blood cells

b1 !i conca(e disc increases S;9 ol1 for #2u)take+

not9 flattened1

:o nucleus lea(es more s)ace for /b+

Contains /b which has an affinity for.combines with #2+

4lexible sha)e.elastic membrane allows cells to sBuee


14/29


A,ailale

8/ a1 ;& /eart muscle is myogenic.contraction is initiated from

within the muscle itself

not9 heart1

!& "nitiated at the S;:.)acemaker&

C& Wa(e of de)olarisaton.im)ulses.excitation1 )ass o(er atria

walls causing contraction of atria&

& Cannot )ass to (entricles because of layer of non

conducti(e.insulati(e1 tissue.collagen fibres&

E& @ight left1 both atria contract simultaneously.eB&

4& e)olarisaton.im)ulses con(erges on.arri(es at the ;:&

& =ention of delay&

/& So that atria contract before (entricles&

"& e)olarisation )asses down se)tum walls&

J& Through Aurkyne.Aurkin>e tissues.!undles of /is&

D& To a)ex of heart&

$& e)olarisaton )asses u)wards through (entricle

walls.muscle&

=& So heart contracts from a)ex u)wards&

:& So )ushing blood into the arteries.A;.;orta&

#& Some mention of ner(ous su))ly to heart.mention of effect

of adrenaline&

.2 ;ar+# fro; t=e a,ailale .6

2


15/29


A,ailale

b1 ;& Aores in the leaf e)idermis* bordered by guard cells

!& "nner wall thicker than outer

C& Aresence of chloro)lasts

& 4ully labelled1 reasonable diagram

E& C change sha)e to allow o)ening and closing.labelled

diagrams

4& ;llow gas exchange

& Control loss of water (a)our from leaf

/& O*enin$I DK)um) acti(ely trans)orts DKions into C

not9 ref& stomata1

"& AS causes C#2le(els to fall.)/ rises

J& and en


16/29

AS MODULE B"


A,ailale

./ a1 suitable tem)+ suitable )/+ nutrient source+ water+ oxygen

not9 warmth.air1

,-

;ny t=reeof abo(e

b1 Sha)e of Cells drawn :ame of rou)

round Coccus.cocci

rod !acillus.bacilli

mark )er column but must match horio#iti,e or

ne$ati,e

A (iolet )ositi(e

B )ink negati(e

Correct colours ,-

Correct grou)s ,-

iii1 Arotein ,-

$i)o)olysaccharide ,-

Total ;ar+# 183

8


17/29


A,ailale

0/ a1 i1 & ingestion MMMMM& 2& digestion MMMMMM ,2-

6& absor)tion MMMM&& 8& egestion MMMMMM

8 correct

6 correct mark

ii1 The breakdown of large* insoluble molecules into small

soluble ones

,-

b1 En?";e S!#trate >ro!ct# Si#e ofsecre#ion

)e)sin

)rotein.

)oly)e)tide

)e)tides

stomach.

gastric )its

)e)tidases )e)tides

amino acids

Aancreas.

small

intestine

li)ase li)ids fatty acids

and

glycerol

)ancreas

sali(ary1

amylase starch.amylose

maltose sali(ary

gland

mark for each correct row ,8-

c1 i1 rawing showing brush border labelled ,-

rawing showing goblet labelled ,-

ii1 Correct function of brush border cell ,-

Correct function of goblet cell ,-

iii1 =icro(illi.brush borderlarge surface area.mitochondria

for acti(e trans)ort.'goblet' to store mucus.any feature of

secretion* e&g& (esicles

,-

Total ;ar+# 1.03

3


18/29


A,ailale

4/ a1 i1 Chloro)hyll a+ chloro)hyll b+ xantho)hyll* carotene*

carotenoid

,-

;ny t=reeof abo(e

ii1 ;llows light of different wa(elengths to be absorbed ,-

b1 i1 @ate of )hotosynthesis+ ,-

at different wa(elengths ,-

ii1 ;xis correctly labelled* rate of )hotosynthesis ,-

$ine drawn to show )eaks that coincide ,-

iii1 The wa(elengths of light most absorbed are the

wa(elengths used in the biochemical reactions owtte&

,-

c1 i1 )hotosystems ,-

ii1 )hotolysis ,-

iii1 ? :;A ,-

% water ,-

N oxygen ,-

i(1 ) electrons ,-B )rotons ,-

(1 ;cce)ting or donating electrons ,-

(i1 ?/2.:;A/2 ,-

(ii1 Source of reducing )ower.to reduce C#2.adding hydrogen

to A; to form ;$A1&

,-

Total ;ar+# 1.93

5


19/29


A,ailale

5/ a1 i1 ;TA.adenosine tri)hos)late ,-

ii1 Aurine base correctly circled on diagram ,-

iii1 ;A.adenosine di)hos)hate ;: )hos)hate ,-

i(1 "t occurs in all cells. all organisms. all metabolic reactions ,-

b1 i1 ; intermembrane s)ace ,-

! matrix ,-

ii1 lycolysis.$ink reaction.Dreb's cycle ,-

;ny two mark each ,-

iii1 A )um) )rotons from matrix into intermembraces)ace.ref& acti(e trans)ort ,-

C carry electrons from )um) to )um)1. electrontrans)ort

,-

i(1 Aro(ide energy for )um)s ,-

(1 ;TA synthetase.synthase acce)t ;TA ase1not9 stalked )articles1

,-

(i1 con(erts ;AKAi1 to ;TA+ ,-

Gsing energy from )rotons mo(ing down

electrochemical1 gradientchemiosmosis Bualified

,-

Total Mar+# 1.53

6/ a1 i1 " humoral ,-

"" cell mediated ,-

ii1 ? ! lym)hocyte.cell ,-

% T lym)hocyte.cell ,-

iii1 !one marrow ,-

i(1 =emory cell ,-

Aroliferate.)roduce antibodies immediately1 on nextcontact with the s)ecific antigen. )athogen

,-

(1 /el)er cell1* killer cell1* su))ressor cell1* memory cell1 ,2-

;ny 6 of abo(e for 2 marks 2 for mark1not9 abbre(iations1

(i1 Stimulate )roduction of ! cells.cytotoxicity.Switch off

cell mediated res)onse at end of immuneres)onse.)roliferate on next contact. destroy )athogens bylysis

,-

7


20/29


A,ailale

b1 i1 T cells.lym)hocytes multi)ly in res)onse to )resence of

(irus. antigen. )art of )rimary res)onse

not9 )rimary res)onse unBual1

,-

ii1 irus )articles are inside T cells.T cells destroy (irus )articles

not9 ref& to antibodies1

,-

iii1 They do not ha(e enough T cells to defend against

)athogens& owtte

not9 immune system weakened1

,-

c1 The antibodies raised in the immunisation will also attack human

cells. cell membranes&

,-

Total ;ar+# 1.53

F


21/29


A,ailale

7/ a1 ;& ;ll materials are added at start.not during the )rocess+ ,-

!& Sterile a))aratus+ ,-

C& Aure culture1 ofPenicillium (notatum); ,-

& Sterile nutrient medium+ ,-

E& ;eration method.oxygen for res)iration+ ,-

4& )/ ad>ustment.buffer+ ,-

& 4ilters for introduction of sterile air.oxygen+ ,-

/& =ethod of mixing Bualified+ ,-

"& Water >acket to control tem)erature.Bualified+ ,-

J& ;llow growth )hase to take )lace.lucose is de)leted

during growth )hase+

,-

D& Aenicillin is secondary metabolite+ ,-

$& Aenicillin is )roduced.har(est after growth )hase. during

stationary )hase. after nutrient de)letion+

,-

=& 4ilter culture fluid. se)arate fungus+ ,-

:& Aurify filtrate.chemically modify antibiotic+ ,-

#& ;A e&g& )enicillin )roduction in nature )ossibly to reduce

com)etition. com)arison with continuous culture&

,-

=aximum 0 from 3 a(ailable&

b1 ;& Aarasite in sali(ary gland of mosBuito. ref& to sali(a+ ,-

!& Aasses into blood stream when mosBuito bites+ ,-

C& "n(ades li(er cells+ ,-

& "n(ades red blood cells+ ,-E& Taken in when mosBuito feeds+ ,-

4& Aasses to sali(ary gland of mosBuito+ ,-

& Are(ent adult biting+ ,-

/& :ets.clothing.re)ellants+ ,-

"& Control mosBuito )o)ulation+ ,-

J& "nsecticide Bualified.T to kill adults or lar(ae+ ,-

D& rain.co(er standing water to )re(ent egg laying.lar(ae

de(elo)ing+

,-

$& S)ray oil.detergent on water to drown lar(ae+ ,-

=& 4ish to eat.bacteria to infect lar(ae.biological control+ ,-

:& Sterilisation.infertile males to )re(ent re)roduction+ ,-#& Correct reference to difficulty of treating.(accinating in

order to reduce )ool of infected humans. ref& to

)ro)hylaxis

,-

=aximum 0 from 3 a(ailable&

Total ;ar+# 1.23


22/29

AS MODULE B$


A,ailale

./ a1 i1 ; I Aetals acce)t Corolla

! I Stigma

C I ;nther not 9 )ollen.stamen1

I Se)als acce)t calyx not 9 bract1

E I #(ary not 9 car)el.o(ule1 ,3-

ii1 $arge )etals+

Stamens.anther.stigma inside flower+

not 9 high stigma1

car)el inside flower+

nectary+,=ax 2-

b1 i1 rowth1 organised.controlled by tube nucleus+

En


23/29


A,ailale

4/ a1 Long haired bron short haired blac!

hhbb //!!

not 9 if ga) or colon etc between letter )airs1

hb /!

4 /h!b

4 Short hair !lack

no error carried forward1

,2-

,-

,-

,-

b1 /!& /b& h!& hb ,-

Short haired !lack //!!+ //!b+ /h!!+ /h!b

Short haired !rown bb//+ bb/h+

$ong haired !lack& !!hh+ !bhh

$ong haired !rown bbhh ,F-

%&o#al

!"'

5/ a1 mark each correct label and )osition of cell body

Sensory9 into dorsal root with ganglion in grey matter&

@elay9 in grey matter with cell body in grey matter

=otor9 cell body in grey matter* out of (entral root on same side

as sensory&

,6-

b1 White matter axons and dendrons1 myelin sheath.no cell bodies

;cce)t ora grey matter* cell bodies no myelin sheath

,-

c1 Syna)tic (esicles.rece)tor sites only on )resyna)tic.one side of

syna)se+

Ex)lanation of refractory )eriod Bualified+

,2-

d1 a1 Slow it down+

b1 e)olarisation . action )otential at the node not 9 im)ulse1+

c1 from one node of @an(ier1 to next called Saltatory

conduction1+

d1 !ecause sodium and )otassium ions cannot )ass across

myelin sheath+

e1 :o myelin sheath local circuit conduction+

,=ax 8-

%&o#al!0'

2


24/29

22


25/29


A,ailale

6/ a1 ; efinition of s)ecies+

! Are(enting allele . gene flow . interbreeding+

C ifferences arise because1 mutation random1+

Selection )ressures are different or described+

E eogra)hical.allo)atric Bual+

4 !eha(ioural Bual+

mor)hological.mechanical Bual+

/ sym)atric Bual.seasonal isolation+

" /ybrid sterility+

J 4ittest sur(i(e+ term needed1

D Aass on fa(ourable alleles+ not 9 genes1

$ :atural selection+ term needed1

= e&g& ala)agos finches+

: :o com)etition for a(ailable niches+

# ;da)ti(e radiation term needed in context1

A ;A& e&g& ref enetic drift* founder )rinci)le ex)lained

=ax 0

26


26/29


A,ailale

b1 ; @ef& )oints ! in )roximal con(oluted tubule& "f two of

following used in context+

! Water absorbed by #smosis+

C lucose absorbed by cotrans)ort acce)t ;TA reBuired .

acti(e trans)ort+

Some substances absorbed by diffusion* e&g& it ; D E

chloride ions+ exam)le needed1

E Selecti(e reabsor)tion . selecti(e absor)tion+

4 Water )otential of filtrate decreases not 9 ref& to

surrounding tissue1+

Aressure dro)s+

/ @ef& to )oints " = in escending1 loo) of /enle if two

used in context+

" :aKle(els u).water mo(es out by osmosis if not abo(e1+

not 9 salt1

J Water )otential down+

D ;scending loo) :aKout . chloride out.walls im)ermeable

to water+

$ Water )otential u)+

= @ef counter current+

: ;/ acts on collecting duct.distal con(oluted tubule+

# so water absorbed ex)lained.because of increased

)ermeability+

A ;A e&g& ref urea out from ACT or from collecting duct to

lower WA.@ef& secretion creatinine* )enicillin into

ACT.aBua)orins&

28


27/29


A,ailale

7/ a1 i1 @:; . nucleotides+ not 9 t@:;.r@:;1 ,-

ii1 ;cti(e site ,-

iii1 Secondary.al)ha /elix not 9 coil.s)iral1

Tertiary 6 dimensional folding acce)t globular

not 9 ref& SS bridges etc.more than one 6 structure i&e&

Buaternary1

,-

,-

b1 i1 @e(erse transcri)tase uses @:; as a tem)late 1 to make

:; 1

,2-

ii1 ifferent amino acid seBuence1 made+

ifferent (iral1 )rotein will be made+

iral1 Arotein is an antigen;ntigen changes+

;ntibodies are s)ecific.do not recognise new antigen+,6-

c1 i1 ;ttaches to en


28/29


A,ailale

9/ a1 i1 Con(erted into a form which is useable by li(ing

organisms&

,-

ii1 :itrogen fixing bacteria or exam)le

"ndustrial fixation . /aber )rocess .

Electrical storms+

;ny two for mark& not 9 root nodules1

,2-

iii1 enitrifying bacteria con(ert nitrates into atmos)heric

nitrogen.less nitrates in water logged soils.)lants don't rely

on soil nitrates+

"nsecti(orous )lants digest )rotein and absorb amino acidsuse nitrogen from these acce)t ref :;+ ,-

b1 i1 Carry out chemical reaction . named+ ,-

ii1 Electron transfer chain . cytochromes.electron carriers+

not 9 ETC.)hotosystems1

,-

iii1 Gsed to )um) )rotons+

"nto bacterial cell1 wall+

Creates )roton gradient . )roton moti(e force.

electrochemical gradient . )/ radient . high concentration

)rotons in wall ,2 =ax-

i(1 Arotons mo(e down gradient into cyto)lasm1+

Through stalked )articles* )roteins.)rotein channels+

Causes ;TA synthetase . synthase+

To )roduce ;TA from ;A and iA.)hos)horylation of ;A+

,=ax 6-

c1 /ydrogen from reduced :;+

is used to reduce carbon dioxide.donate to glycerate 6 )hos)hate+

using energy from ;TA+

to make glucose.triose )hos)hate+

not 9 sugar1

,=ax 6-

CE !iology =arking Scheme Summer 20071.E

25


29/29

Welsh Joint Education Committee

283 Western ;(enue

Cardiff& C43 2%?

Tel& :o& 02 2025 3000

4ax& 02 2037 38

Email9 examsPw>ec&co&uk

website9www&w>ec&co&uk.exams&html
mailto:[email protected]://www.wjec.co.uk/exams.htmlhttp://www.wjec.co.uk/exams.htmlmailto:[email protected]://www.wjec.co.uk/exams.html

1-1. GCE Biology Marking Scheme (Summer 2007)

Documents

Transcript of 1-1. GCE Biology Marking Scheme (Summer 2007)