ocr f215 jan 11 control genomes and environment ms mark scheme

8/6/2019 OCR F215 JAN 11 Control Genomes and Environment MS MARK SCHEME

1/19

GCE

Oxford Cambridge and RSA Examinations

Unit F215: Control, Genomes and Environment

Advanced GCE

Biology

Mark Scheme for January 2011


2/19

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This mark scheme is published as an aid to teachers and students, to indicate the requirements of theexamination. It shows the basis on which marks were awarded by Examiners. It does not indicate thedetails of the discussions which took place at an Examiners meeting before marking commenced.

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3/19

F215 Mark Scheme

1

Question Expected Answer Mark A

1 (a) (i) Mark the first sugg

1

2

34

5

6

7

idea that(produces)large , yield / volume / amount, of milk ;

idea of long lactation period ;

idea of high milk quality ;large udders/

correct udder shape (for milking machine) ;

resistance to , (named) disease / mastitis / pathogensoreffective immune system ;

idea of calm temperament ;

AVP ;

3 max

1

2

3

4

5

6

7

DO NOT CRED

DO NOT CRED

DO NOT CRED

CREDIT docile

eg

walk

idea

1 (a) (ii) normal shaped curve ;

shifted to the right of original ;

2

Position of curve mu

curvemustend

mustnotstart t

maystart at sam


4/19

F215 Mark Scheme

2


1 (a) (iii) Mark the first sugg

123456

7

8

artificial insemination / AI ;in vitro fertilisation / IVF ;idea of progeny testing ;embryo transplantation / use of surrogate mother;cloning ;genetic screening / use of gene probes ;

AVP ;

AVP ;2 max

1

2

3

4

5

6

7

8

IGNORE perfo

CREDIT embry

ACCEPT gene

eg sex s

eg portm

1 (b) (i) idea of change to , DNA / base(s) / nucleotide(s) ;1

1 (b) (ii) natural / directional , selection ;

1

ACCEPT evolution

DO NOT CREDIT g

1 (c) (i) regulatoryidea that makes , repressor protein / transcription factororidea that product switches (structural / another) gene ,

on / off;

structuralidea that makes , enzyme / polypeptide / protein ;

relationship between the 2

idea that regulatory gene , controls / affects ,the expression of structural gene ;

2 max

ACCEPT makes re

ACCEPT switchingIGNORE explanatio


5/19

F215 Mark Scheme

3


1 (c) (ii) lactose has been ,removed / digested / respired /broken down (by bacteria) ;

to , lactic acid / lactate / other sugars ;

yogurt still a good source of, calcium / vitamins ;2 max

DO NOT CREDIT i

eg glucose (and

1 (d) 123

4

5

lactose binds to repressor protein ;changes , shape / structure (of protein) ;removes it from / stops it binding to , operator;

RNA polymerase binds to promoter;

idea that (so that Z and Y) are ,transcribed / mRNA made ;

3 max

1

2

3

4

5

DO NOT CREDIGNORE ref. to

DO NOT CRED

CREDIT lactose

IGNORE gene

Total 16


6/19

F215 Mark Scheme

4


2 (a)voluntary(skeletal)

involuntary(smooth)

cardiac

cellularstructure

*striated /bands of actin &

myosinor

cylindrical cells

ormultinucleate ;

*unstriated /*non striated

orspindle-

shaped cellsor

uninucleate ;

*striated

orbranched

cellsor

uninucleateor

interlocking /junctions /intercalated

discs ;

functionto move ,bones /

skeleton /joints /

(named) limbs ;

idea of**controllingdiameter of,

arteries /arterioles /bronchi /

bronchiolesor

peristalsisor

uterine

contractionor

control pupilsize ;

to pumpblood / AW ;

6

For each box, marmark being awardeis incorrect or contra

IGNORE informatiothat is identical to 1s

different (as Q asks

eg striated()

multinucleate(

striated() multinucleate

CREDIT drawings if

striated / mu

* ACCEPT descript

** ACCEPT controlblooddiamdiam

** CREDIT vasoconfor co


7/19

F215 Mark Scheme

5


2 (b) voluntaryintercostal / diaphragm ;

involuntarybronchi / bronchioles / arteries / arterioles / aorta /

oesophagus ;

cardiacheart ;

3

CREDIT trapezius /l

ACCEPT between

DO NOT CREDIT nIGNORE gut unqua

ACCEPT walls of,

2 (c) (cardiac) D ;(clapping) B ;(bicycle) C ;

3

2 (d)

1

23

4

5

6

monkeys rather than ratsidea that (humans & monkeys) closely related /

share more genes / share a common ancestor;(humans & monkeys) both primates ;idea that brain / body ,

structure / physiology / behaviour,similar (to humans) ;

monkey brain bigger (than rat) ;max 2

comment

argument in favour;

argument against ;max 2

3 max

1

2

3

4

5

6

MAXIMUM 2 m

DO NOT CRED

ACCEPT havin

eg to allevia

eg causes ,DO NOT CRED

right to


8/19

F215 Mark Scheme

6


2 (e) ACCEPT phonetic sp

123

456

7

C8

C9

S10

S11

S12

S13

S14

S15

V16

V17

V18

19

appropriate parts of nervous / endocrine systemssympathetic (motor neurones) stimulated ;noradrenaline / norepinephrine ;neurotransmitter released at ,

neuromuscular junction / organs ;adrenaline (secreted / released into blood) ;from adrenal , glands / medulla ;idea of adrenaline / noradrenaline ,

binding to receptors (on target tissue) ;AVP ;

effect on structures containing 3 types of muscleidea of heart beats faster;idea of heart beats more forcefully ;

alter blood flow / increase blood pressure ;

less blood flow to , gut / skin ;reducing gut secretions / making skin pale ;smooth muscle in gut relaxes / peristalsis slows down ;smooth muscle in airways relaxes / airways wider;iris radial muscle contracts / pupil dilates ;

idea of breathing / intercostals contracting /diaphragm contracting , faster;

more blood flow to (skeletal) muscles ;idea of(named skeletal) muscles being primed for action ;

AVP ;8 max

1

2

3

4

5

6

7

C8

C9

S10

S11

S12

S13

S14

S15

V16

V17

V18

19

May be awarde

eg corr corr

C = cardiac

S = smootheg cont

ACCEPT involACCEPT invol

V = voluntary

ACCEPT leg CREDIT glyco

eg erec

QWC linking structure to response ; 1 Award if 2 diffecorre2 diffe

Total 24


9/19

F215 Mark Scheme

7


3 (a)

123

4

5

6

7

8

climate - tropical versus temperatetropical has

highertemperature / hotter;more (sun)light / days longer;photosynthesis faster;

idea thatmore storage of, organic molecules / biomass / energyormore formation of, organic molecules / biomass ;

AVP ;

vegetation - woodlandorrainforest versus grassland(s)woodlandorforest has

idea of greatercomplexity / greaterbiodiversity /more niches ;

competition for space less limiting ;

AVP ;4 max

CREDIT reverse arg

temperaturelight intensityphotosynthes

biomass mad

eg less seas faster, m

CREDIT reverse arg

eg greater, h

complexitycompetition

3 (b) (bomb) calorimeter;

detail of technique ;

detail of, measurement / analysis ;

2 max

eg known / d

(material)

eg temperatu known vo calculatio


10/19

F215 Mark Scheme

8


3 (c) (i) (perch) 22 ;(cow) 1 ;

2

3 (c) (ii) 1

234

567

higher in bobcat/lower in cow ;

for bobcatmore (energy) absorbed ; oraless (energy / waste) egested ; oracorrect comparative figs. quoted from table ;

meat more digestible ; oramainly protein and fat ;contains no cellulose ; ora

3 max

1

2

3

4

5

6

7

DO NOT CREDIGNORE refs tALLOW ecf if

bobcat 83(%) aorbobcat 17(%) a

3 (c) (iii) If perch is suggeste

If bobcat or cow sug

12

3

4

5

grasshopper;idea of high conversion to biomass figure ;

idea of herbivore / primary consumer /low(er) trophic level than perch ;

idea of more food available ;

idea of one stage of energy loss in food chain not two /more energy passes through food chain (to humans) ;

3 max

1

2

3

4

5

ACCEPT ref toACCEPT mp2

Total 14


11/19

F215 Mark Scheme

9


4 (a) (i) max 2 for descript

If bacteria mentione

If incorrect units useapply ecf for subseq

1

2

3

4

5

678

descriptionlactose decreases

and qualified ;

ammonia decreasesand qualified ;

ammonia , plateaus / constant ,at c. 2 (a.u.) (between 55 -140 h) ;

max 2

explanationidea that lactose / ammonia , used ,

for growth / to make biomass ;lactose / ammonia , used to make penicillin ;

lactose broken down to glucose (and galactose) ;lactose / glucose , used for, respiration / energy ;ammonia used to make named N-containing molecule ;

max 2

4 max

1

2

3

4

5

6

7

8

eg single figeoo

eg single fig

eo

IGNORE ammeg amino

n


12/19

F215 Mark Scheme

10


4 (a) (ii)

lactose and ammonia levels , stay high / oscillate ;

biomass , continues to rise / does not level off;

2

If bacteria mentioneIGNORE incorrect

DO NOT CREDIT

ACCEPT biomassrefer

4 (a) (iii)

idea that most penicillin produced after main growth phase ;after 24 h / when nutrients declining ;

not needed for growth ;

(however evidence not entirely clear as)production begins during biomass log phase ;

2 max

If bacteria mentioneIGNORE incorrect

4 (b) (i) If bacteria mentione

1

234

5

6

to avoid unwanted microbe , entry / presence ;

so no competition for nutrients ;so conditions remain unchanged ;so no decrease in yield ;

so no contamination of, batch / product / penicillin

orbatch is unusable ;

to prevent escape of,microbes / fungus / Penicillium/ spores ;

3 max

1

2

3

4

5

6

IGNORE patho

DO NOT CRED


13/19

F215 Mark Scheme

11


4 (b) (ii)

temperature - as it affects enzymes ;pH - as it affects enzymes ;oxygen content ref. respiration ;

AVP ;

3 max

If bacteria mentione

DO NOT CREDIT a

eg salt conceaffec

removal oreduc

speed of sensu

Total 14


14/19

F215 Mark Scheme

12

Question Expected Answer Mark

5 (a)

A DNA polymerase/ Taq polymerase ;B restriction endonuclease ;

C (DNA) ligase ;D plasmid(s) ;E reverse transcriptase ;

5

Mark the first answanswer is given thaanswer, then = 0 m

B ACCEPT restrDO NOT ACC

5 (b)1

23

456

hospitalWBCs , easy to obtain / obtained from blood sample ;

WBCs good source of DNA ;mutant genes location unknown /

need to look in whole genome ;

biotechnology companyidea that insulin made in pancreas ;many mRNA copies there / mRNA easier to find ;AVP ;

4 max

1

2

3

4

5

6

ACCEPTidea

eg intro


15/19

F215 Mark Scheme

13


5 (c) For A marks points mthe 2 processes and sin vivo is slow) orusemore, least, most, betscheme.

For the related E maone of the processes(Note that in some caadvantage or as an ex

contd

A1E1

A2E2

A3E3

A4

E4

A5

E5

advantages of PCRPCR quicker ;explanation ;

PCR uses less equipment ;explanation ;

PCR uses less space ;explanation ;

PCR less labour-intensive / easier/(some parts of process) less costly ;

explanation ;

PCR combines selection of gene and amplification butin vivo requires separate steps ;

explanation ;

A1

E1

A2

E2

A3

E3

A4

E4

A5

E5

eg few hou 30 cycle no bact

eg tube an

multiple

eg DNA an no grow in vivo r

eg PCR se in PCR in vivo r

in vivo r

eg primer s in vivo n


16/19

F215 Mark Scheme

14


5 (c) contd A6E6

A7E7

A8E8

A9E9

A10E10

A11

E11

PCR safer;explanation ;

PCR can use lowerquality DNA ;explanation ;

advantages of in vivoin vivo less prone to mutation ;explanation ;

in vivo less expensive ;explanation ;

in vivo less technically complex ;explanation ;

in vivo useful , when gene less well known /as longer piece of DNA can be cloned ;

explanation ;

7 max

A6

E6

A7E7

A8

E8

A9

E9

A10

E10

A11

E11

eg PCR us PCR do

eg can use

eg Taq pol early m exact co

eg materia

PCR ch

eg conditio optimis

eg searchi obtains PCR ha

QWC clearly stated advantage linked to correct explanation ; 1 2 pairs of A & E marks

Total 17


17/19

F215 Mark Scheme

15


6 (a) Mark the first answof (a). If an additioncontradicts the corre

ACCEPT phonetic

6 (a) (i) tropism(s) ;1

IGNORE named tro

6 (a) (ii) (plant) hormone / growth substance / growth regulator / pgr;1

6 (a) (iii) deciduous ;1

6 (a) (iv) conservation ;1

DO NOT CREDIT p

6 (a) (v) decomposer(s) ;

1

ACCEPT saprotropIGNORE fungi / ba

DO NOT CREDIT d

6 (a) (vi) nitrogen fixation ;

1

ACCEPT nitrogen fiDO NOT CREDIT n

6 (b) (i) stimulus identified ;organism named and normal response described ;

response , stops / lessens ,after repeated stimulation / over time ;

3

eg toucheg sea anem

learning to ignore i

6 (b) (ii) organism named and voluntary behaviour described ;reinforcer / reward / punishment , identified ;

behaviour,increases (for reward) / decreases (for punishment) ,

in frequency ;3

eg dog beggeg food rewa


18/19

F215 Mark Scheme

16


6 (b) (iii)

primate species identified ;

behaviour described ;

purpose / importance , stated ;

3

Marks can be awardinteraction instead odescribed.

CREDIT English naora

IGNORE humans

eg include do

allogroomi communica passing on idea of pro

CREDIT answers re

eg

eg

Total 15


19/19

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ocr f215 jan 11 control genomes and environment ms mark scheme

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