Oxford Cambridge and RSA Examinations

GCE

Biology Advanced Subsidiary GCE

Unit F211: Cells, Exchange and Transport

Mark Scheme for June 2013

OCR (Oxford Cambridge and RSA) is a leading UK awarding body, providing a wide range of qualifications to meet the needs of candidates of all ages and abilities. OCR qualifications include AS/A Levels, Diplomas, GCSEs, Cambridge Nationals, Cambridge Technicals, Functional Skills, Key Skills, Entry Level qualifications, NVQs and vocational qualifications in areas such as IT, business, languages, teaching/training, administration and secretarial skills. It is also responsible for developing new specifications to meet national requirements and the needs of students and teachers. OCR is a not-for-profit organisation; any surplus made is invested back into the establishment to help towards the development of qualifications and support, which keep pace with the changing needs of today’s society. This mark scheme is published as an aid to teachers and students, to indicate the requirements of the examination. It shows the basis on which marks were awarded by examiners. It does not indicate the details of the discussions which took place at an examiners’ meeting before marking commenced. All examiners are instructed that alternative correct answers and unexpected approaches in candidates’ scripts must be given marks that fairly reflect the relevant knowledge and skills demonstrated. Mark schemes should be read in conjunction with the published question papers and the report on the examination. OCR will not enter into any discussion or correspondence in connection with this mark scheme. © OCR 2013

F21

1 M

ark

Sch

em

e Ju

ne

2013

1

An

no

tati

on

s A

vaila

ble

in S

CO

RIS

An

no

tati

on

M

ean

ing

Ben

efit

of D

oubt

Con

trad

ictio

n

Cro

ss

Err

or C

arrie

d F

orw

ard

Giv

en m

ark

Ext

enda

ble

horiz

onta

l wav

y lin

e

Igno

re

QW

C

Ben

efit

of th

e do

ubt n

ot g

iven

addi

tiona

l QW

C c

redi

t giv

en

Tic

k

Tic

k 1

Tic

k 2

Om

issi

on M

ark

F21

1 M

ark

Sch

em

e Ju

ne

2013

2

Qu

esti

on

A

nsw

er

Mar

ks

Gu

idan

ce

1 (a

) (i

) A

nuc

leus

;

B c

hlor

opla

st ;

2

Mar

k th

e fi

rst

answ

er o

n e

ach

pro

mp

t lin

e. If

the

answ

er

is c

orre

ct a

nd a

n ad

ditio

nal a

nsw

er is

giv

en th

at is

inco

rrec

t or

con

trad

icts

the

cor

rect

ans

wer

the

n =

0 m

arks

D

O N

OT

CR

ED

IT n

ucle

ar e

nvel

ope

/ nu

cleo

lus

IGN

OR

E c

hlor

ophy

ll

(ii)

C

m

itoch

ondr

ion

(

aero

bic)

res

pira

tion

/ pro

duci

ng A

TP

/ re

leas

e en

ergy

;

D S

ER

/ sm

ooth

end

opla

smic

retic

ulum

tra

nspo

rt /

prod

uctio

n / p

roce

ssin

g, o

f, fa

ts /

lipid

s /

ste

roid

s / c

arbo

hydr

ates

;

2

Mar

k th

e fi

rst

answ

er o

n e

ach

pro

mp

t lin

e. If

the

answ

er

is c

orre

ct a

nd a

n ad

ditio

nal a

nsw

er is

giv

en th

at is

inco

rrec

t or

con

trad

icts

the

cor

rect

ans

wer

the

n =

0 m

arks

D

O N

OT

CR

ED

IT F

unct

ion

of o

rgan

elle

if o

rgan

elle

id

entif

ied

/ nam

ed in

corr

ectly

(as

this

wou

ld b

e an

inco

rrec

t bi

olog

ical

sta

tem

ent.

D

O N

OT

CR

ED

IT m

akes

/ pr

oduc

es, e

nerg

y A

CC

EP

T p

rodu

ces

AT

P fo

r re

spira

tion

IGN

OR

E r

ef to

tran

spor

t / m

odifi

catio

n of

pro

tein

s D

O N

OT

CR

ED

IT r

ef p

rodu

ctio

n of

pro

tein

s

(b)

C

/ m

itoch

ondr

ion

/ cris

tae,

too

smal

l ;

reso

lutio

n (o

f lig

ht m

icro

scop

e),

not h

igh

(eno

ugh)

OR

id

ea o

f onl

y, 0

.2µ

m /

200n

m ;

w

avel

engt

h of

ligh

t too

long

;

m

ax 2

idea

of

too

smal

l / n

ot b

ig e

noug

h im

port

ant

IGN

OR

E

very

sm

all

AC

CE

PT

res

olut

ion

low

IG

NO

RE

ref

to m

agni

ficat

ion

fo

r re

solu

tion

acce

pt a

ny v

alue

in r

ange

0.0

5 -

0.2

µm

IG

NO

RE

ref

to

elec

tron

mic

rosc

ope

F21

1 M

ark

Sch

em

e Ju

ne

2013

3

(c

)

mak

es v

isib

le /

easi

er to

see

/ se

e m

ore

deta

il ;

(sta

inin

g) p

rovi

des

/ in

crea

ses,

con

tras

t ;

iden

tify

/ rec

ogni

se, c

ell t

ypes

/ or

gane

lles

/ pa

rts

of c

ell ;

id

entif

y / r

ecog

nise

, diff

eren

t (n

amed

), c

ompo

unds

/

mol

ecul

es ;

max

2

AC

CE

PT

dis

tingu

ish,

cel

ls /

org

anel

les,

(fr

om b

ackg

roun

d)

IGN

OR

E r

ef t

o cl

arity

IG

NO

RE

su

bsta

nces

T

ota

l8

F21

1 M

ark

Sch

em

e Ju

ne

2013

4

Qu

esti

on

A

nsw

er

Mar

ks

Gu

idan

ce

2 (a

) (i

) 0.

6 : 1

; ;

2

Cor

rect

ans

wer

= 2

mar

ks

Rat

io m

ust

be

corr

ect

way

ro

un

d

1: 0

.6 is

not

cor

rect

but

ca

n st

ill a

llow

mar

k fo

r co

rrec

t wor

king

if s

how

n If

answ

er in

corr

ect

AL

LO

W 1

mar

k fo

r w

orki

ng

e.

g.

600

÷ 10

00

600

: 100

0 =

1 m

ark

(ii)

as

SA

:VO

L ra

tio d

ecre

ases

rat

e of

diff

usio

n de

crea

ses

O

R

as S

A:V

OL

ratio

incr

ease

s ra

te o

f di

ffusi

on in

crea

ses

;

use

of tw

o pa

irs o

f fig

ures

with

cor

rect

uni

ts (

mm

s-1)

for

rat

e to

illu

stra

te tr

end

;

ref

to r

ate

of d

iffus

ion

in e

ither

of

the

first

tw

o cu

bes

not

f

ittin

g tr

end

;

m

ax 2

AC

CE

PT

po

sitiv

e co

rrel

atio

n

DO

NO

T C

RE

DIT

as

rate

of

diffu

sion

dec

reas

es S

A:V

OL

ratio

dec

reas

es

use

of fi

gs r

equi

res

ratio

quo

te a

nd r

ate

quot

e at

two

poin

ts

e.g.

at S

A:V

OL

of 3

:1 r

ate

is 0

.02

mm

s-1, a

t SA

:VO

L ra

tio o

f 0.

2:1

rate

is 0

.013

(co

rrec

t un

its o

nly

need

to

be u

sed

once

) D

O N

OT

CR

ED

IT if

uni

t for

SA

:Vol

giv

en

AC

CE

PT

cor

rect

cal

cula

tion

of r

ate

chan

ge

e.g.

whe

n th

e S

A:V

OL

ratio

was

3:1

the

rate

of d

iffus

ion

was

0.

020m

ms-1

whi

ch is

0.0

07m

ms-1

fast

er th

an th

e cu

be w

ith

0.2:

1 S

A:V

OL

ratio

(iii)

(larg

e pl

ants

) ha

ve a

, sm

all /

low

, SA

: V

OL

ratio

;

idea

of d

iffus

ion

too

slow

(to

sup

ply

requ

irem

ents

) ;

idea

of

need

tran

spor

t sys

tem

(fo

r w

ater

/ m

iner

als

/

as

sim

ilate

s) ;

id

ea o

f ne

ed (

spec

ial)

surf

ace

area

for,

gas

eous

exc

hang

e

/ u

ptak

e of

min

eral

s ;

max

2

DO

NO

T C

RE

DIT

sm

alle

r un

less

we

know

sm

alle

r th

an w

hat

AC

CE

PT

e.g

. lar

ger

plan

ts h

ave

a sm

alle

r S

A :

Vol

rat

io

mus

t hav

e id

ea o

f too

slo

w

AC

CE

PT

diff

usio

n ta

kes

too

long

D

O N

OT

CR

ED

IT t

rans

port

of

gase

s

F21

1 M

ark

Sch

em

e Ju

ne

2013

5

Qu

esti

on

A

nsw

er

Mar

ks

Gu

idan

ce

(b

) (i

) di

vide

d le

ngth

of s

ide

by ti

me

take

n ;

1 IG

NO

RE

div

ide

mm

by

s (u

nits

alo

ne to

o va

gue)

(ii)

id

ea th

at s

tude

nt u

sed

who

le le

ngth

of

side

, ra

ther

tha

n ha

lf le

ngth

;

1

AC

CE

PT

ne

eds

to d

ivid

e an

swer

by

2 / d

ista

nce

has

to b

e to

ce

ntre

of

cube

rat

her

than

who

le le

ngth

of

side

/ as

sum

ed

diff

usio

n oc

curs

(ac

ross

who

le c

ube)

fro

m o

ne s

ide

(c

)

sq

uam

ous

epith

eliu

m

shor

t(er

) di

ffusi

on, d

ista

nce

/ pat

h ;

larg

e nu

mbe

r of a

lveo

li la

rge(

r) s

urfa

ce a

rea

;

good

blo

od s

uppl

y hi

gh /

larg

e / s

teep

, co

ncen

trat

ion

grad

ient

O

R

rem

oves

oxy

gen

(fro

m lu

ng s

urfa

ce)

/ brin

gs c

arbo

n

dio

xide

(to

lung

sur

face

);

go

od v

entil

atio

n hi

gh /

larg

e / s

teep

, co

ncen

trat

ion

grad

ient

O

R

su

pplie

s ox

ygen

(to

alv

eoli)

/ re

mov

es

carb

on d

ioxi

de

(fr

om a

lveo

li) ;

4

AC

CE

PT

re

duce

d /

shor

ter

diff

usio

n di

stan

ce

AC

CE

PT

thi

n di

ffus

ion

barr

ier

IGN

OR

E t

hin

diff

usio

n pa

thw

ay

AC

CE

PT

incr

ease

s su

rfac

e ar

ea

IGN

OR

E S

A :

Vol

rat

io

AC

CE

PT

mai

ntai

ns /

cre

ates

con

cent

ratio

n gr

adie

nt

IGN

OR

E r

ef d

iffus

ion

grad

ient

A

CC

EP

T m

aint

ains

/ c

reat

es c

once

ntra

tion

grad

ient

IG

NO

RE

ref

diff

usio

n gr

adie

nt

IGN

OR

E r

ef to

air

T

ota

l12

F21

1 M

ark

Sch

em

e Ju

ne

2013

6

3 (a

) (i

) m

itosi

s /

mito

tic ;

1 C

orre

ct s

pelli

ng o

nly

(ii)

fo

ur c

hrom

osom

es o

n eq

uato

r ;

(eac

h ch

rom

osom

e as

) tw

o si

ster

chr

omat

ids

;

2

If th

e im

age

is u

ncle

ar th

en p

enci

l or

a di

ffere

nt c

olou

r m

ay

have

bee

n us

ed -

RA

ISE

AN

EX

CE

PT

ION

A

war

d 2

ma

rks

for

the

follo

win

g

DO

NO

T C

RE

DIT

mp

1 if

nucl

ear

mem

bran

e sh

own

DO

NO

T C

RE

DIT

mp

1 if

hom

olog

ous

chro

mos

omes

pai

red

e.g.

D

O N

OT

CR

ED

IT m

p 2

if s

iste

r ch

rom

atid

s ar

e no

t joi

ned

(at

cent

rom

ere)

F21

1 M

ark

Sch

em

e Ju

ne

2013

7

(iii)

arro

w fr

om R

to T

;

arro

w fr

om R

to S

AN

D a

rrow

from

S to

T

OR

ar

row

from

R to

S to

T ;

2

e.g.

If co

ntra

dict

ory

arro

ws

to th

e ab

ove

are

dra

wn,

app

ly C

ON

fo

r ea

ch a

rrow

goi

ng fr

om lo

w

to

high

.

e.

g.

g

ets

0

(b)

th

is is

whe

re c

ambi

um /

mer

iste

m /

xyle

m /

phlo

em /

v

ascu

lar

bund

le, i

s fo

und

;

mito

sis/

cell

divi

sion

, occ

urs

in c

ambi

um (

to p

rodu

ce n

ew

cells

for

grow

th)

; ne

w c

ells

, diff

eren

tiate

/ sp

ecia

lise,

(in

to x

yle

m a

nd p

hloe

m)

; xy

lem

sup

plie

s w

ater

for,

(ce

ll) e

long

atio

n / (

cell)

gro

wth

; ph

loem

sup

plie

s, s

ugar

s / a

ssim

ilate

s, f

or, e

nerg

y / g

row

th

/res

pira

tion

; m

ax 2

CR

ED

IT f

rom

a la

belle

d di

agra

m

CR

ED

IT d

esc

riptio

n of

pos

ition

bei

ng c

lose

to

the

edge

of

trun

k D

O N

OT

CR

ED

IT r

esp

onse

s th

at s

ugge

st th

at c

ambi

um e

tc.

are

in o

r ou

tsid

e ba

rk O

R u

nder

cut

sur

face

A

CC

EP

T c

ambi

um d

iffer

entia

tes

IG

NO

RE

nu

trie

nts

R

S

T

R

S

T

F21

1 M

ark

Sch

em

e Ju

ne

2013

8

(c

)

tip /

apex

, of,

shoo

t / r

oot ;

mer

iste

m ;

bu

d ;

max

1

Mar

k th

e fi

rst

answ

er o

n e

ach

pro

mp

t lin

e. If

the

answ

er is

co

rrec

t and

an

addi

tiona

l ans

wer

is g

iven

that

is in

corr

ect o

r co

ntra

dict

s th

e co

rrec

t an

swer

the

n =

0 m

arks

IG

NO

RE

ro

ot o

r sh

oot

unqu

alifi

ed

AC

CE

PT

be

hind

roo

t tip

(d

)

allo

w o

xyge

n to

rea

ch, c

ells

/ tis

sues

(un

der

bark

) ;

fo

r (a

erob

ic)

resp

iratio

n ;

anim

als

tran

spor

t oxy

gen

in, b

lood

/ ci

rcul

atio

n /

tr

ansp

ort s

yste

m ;

pl

ants

do

not t

rans

port

(m

uch)

oxy

gen

in tr

ansp

ort

sys

tem

;

idea

that

(ox

ygen

not

sup

plie

d fr

om le

aves

as)

sto

mat

a

onl

y op

en in

day

/ no

leav

es in

win

ter

;

m

ax 2

IGN

OR

E r

efs

to n

eed

for

CO

2 / p

hoto

synt

hesi

s th

roug

hout

A

CC

EP

T c

orre

ct fo

rmul

a O

2 D

O N

OT

CR

ED

IT o

xyg

en fo

r ph

otos

ynth

esis

A

CC

EP

T g

as(

es)

for

oxyg

en

AC

CE

PT

ga

s(es

) fo

r ox

ygen

T

ota

l10

F21

1 M

ark

Sch

em

e Ju

ne

2013

9

Qu

esti

on

A

nsw

er

Mar

ks

Gu

idan

ce

4 (a

) (i

) 1

pla

cent

a ha

s lo

w p

O2

;

2 a

dult

(oxy

)hae

mog

lobi

n w

ill, r

elea

se O

2 /

diss

ocia

te,

(in, l

ow p

O2

/ pl

acen

ta) ;

3

feta

l hae

mog

lobi

n ha

s hi

gher

affi

nity

for

oxyg

en /

d

escr

ibed

;

4 fe

tal h

aem

oglo

bin,

is (

still

) ab

le to

take

up

(so

me)

oxy

gen,

in p

lace

nta

/ at l

ow(e

r) p

O2

;

m

ax 3

AC

CE

PT

oxy

gen

tens

ion

for

pO2

thro

ugho

ut

IGN

OR

E l

ow

er

Thi

s m

ust b

e a

com

para

tive

stat

emen

t C

RE

DIT

Idea

that

fet

al h

aem

oglo

bin

pick

s up

mor

e ox

ygen

th

an t

he a

dult

haem

oglo

bin

at a

giv

en p

O2 /

feta

l hae

mog

lobi

n pi

cks

up o

xyge

n a

t low

er p

O2

IGN

OR

E r

ef t

o ea

sier

/ q

uick

er,

upta

ke o

f O

2 T

his

is n

ot a

com

para

tive

poin

t, t

he e

mph

asis

is o

n th

e ab

ility

of

feta

l hae

mog

lobi

n to

take

up

som

e ox

ygen

eve

n w

hen

little

is

ava

ilabl

e D

O N

OT

CR

ED

IT if

res

pons

e su

gges

ts t

hat

% s

atur

atio

n in

crea

ses

as p

O2 de

crea

ses

AC

CE

PT

feta

l oxy

haem

oglo

bin

(i

i)

(fet

al)

haem

oglo

bin

may

not

cry

stal

lise

(muc

h)

(at l

ow p

O2)

; re

d bl

ood

cells

do

not c

hang

e sh

ape

;

(fet

al)

haem

oglo

bin

can

pick

up

mor

e ox

ygen

at

low

pO

2

(t

han

sick

le h

aem

oglo

bin)

; id

ea th

at m

ore

oxyg

en, t

rans

port

ed /

deliv

ered

(

arou

nd b

ody)

;

m

ax 2

assu

me

cand

idat

e re

fers

to fe

tal h

aem

oglo

bin

unle

ss a

dult

/ m

ater

nal s

tate

d E

mph

asis

for

this

mp

is th

e fe

tal h

aem

oglo

bin

bein

g ab

le to

pi

ck u

p m

ore

oxyg

en t

han

sic

kle

haem

oglo

bin

C

RE

DIT

(fe

tal)

haem

oglo

bin

beco

mes

mor

e sa

tura

ted

at

low

pO

2 (t

han

sick

le h

aem

oglo

bin)

A

llow

ref

to lo

wer

pO

2 un

less

it is

impl

ied

that

fet

al

haem

oglo

bin

pick

s up

mor

e ox

ygen

at

low

er p

O2 th

an

high

er p

O2

Em

phas

is fo

r th

is m

p is

the

dist

ribut

ion

of o

xyge

n IG

NO

RE

mor

e ox

ygen

obt

aine

d by

per

son

(as

this

impl

ies

brea

thin

g)

F21

1 M

ark

Sch

em

e Ju

ne

2013

10

(b

)

dif

fusi

on

;

from

hig

h co

ncen

trat

ion

to lo

w c

once

ntra

tion

/ dow

n

c

on

cen

trat

ion

gra

die

nt;

(h

ydro

stat

ic)

pre

ssu

re in

cap

illar

y hi

gh(e

r th

an in

tiss

ue

f

luid

) ;

capi

llary

(w

alls

) le

aky

/ des

crib

ed ;

flu

id /

plas

ma,

forc

ed o

ut (

of c

apill

ary)

O

R

fluid

/ pl

asm

a, m

oves

, fro

m h

ighe

r pr

essu

re to

low

er

pres

sure

/ do

wn

pres

sure

gra

dien

t ;

(as

the

fluid

/ pl

asm

a m

oves

out

) gl

ucos

e / o

xyge

n / s

mal

l m

olec

ules

, lea

ve w

ith, f

luid

/ pl

asm

a ;

max

3

IGN

OR

E d

iffus

ion

of g

luco

se t

hrou

ghou

t an

swer

‘d

own

diffu

sion

gra

dien

t’ =

1 fo

r ‘d

iffus

ion’

(m

p 1

no

t m

p 2)

D

O N

OT

CR

ED

IT d

iffus

ion

linke

d to

pre

ssur

e A

CC

EP

T p

O2

for

conc

entr

atio

n A

CC

EP

T p

erm

eabl

e

IGN

OR

E p

ores

/ f

enes

trat

ions

/ h

oles

A

CC

EP

T id

ea o

f sm

all g

aps

betw

een

cells

E

mph

asis

her

e is

on

pres

sure

for

cing

flu

id o

ut

DO

NO

T C

RE

DIT

tis

sue

fluid

for

ced

out

Em

phas

is h

ere

is o

n gl

ucos

e/ o

xyge

n b

eing

car

ried

out a

s a

resu

lt of

mas

s flo

w o

f flu

id (

not

diff

usio

n)

QW

C;

1

awar

d if

any

two

term

s sp

elt c

orre

ctly

and

use

d in

cor

rect

co

ntex

t fro

m:

dif

fusi

on

/ d

iffu

se, p

ress

ure

, hyd

rost

atic

, co

nce

ntr

atio

n g

rad

ien

t

T

ota

l9

F21

1 M

ark

Sch

em

e Ju

ne

2013

11

Qu

esti

on

A

nsw

er

Mar

ks

Gu

idan

ce

5 (a

)

form

s, v

esic

les

/ (na

med

) or

gane

lle(s

) ;

sepa

rate

(co

nten

ts o

f) o

rgan

elle

s fr

om c

ytop

lasm

/

c

ompa

rtm

enta

lisat

ion

; si

te o

f (n

amed

), p

roce

sses

/ r

eact

ions

;

prov

ides

sur

face

for

atta

chm

ent (

of e

nzym

es /

ribos

omes

) ;

cont

rol w

hat s

ubst

ance

s, e

nter

/ le

ave,

org

anel

les

; A

VP

;

max

2

AC

CE

PT

tra

nspo

rt in

ves

icle

s e.

g. is

olat

es D

NA

fro

m c

ytop

lasm

/ se

para

te d

iffer

ent

envi

ronm

ents

/ se

para

te o

rgan

elle

s e.

g. ly

soso

mes

isol

ate

enzy

mes

(a

nd p

reve

nt d

amag

e

to

cells

) e.

g. s

epar

ates

(m

etab

olic

) re

actio

ns

IGN

OR

E a

ny

ref t

o nu

clea

r po

res

DO

NO

T C

RE

DIT

sub

stan

ces,

ent

er /

leav

e, c

ells

e.

g. a

llow

cre

atio

n of

con

cent

ratio

n gr

adie

nts

e.g.

ref

to in

trac

ellu

lar

com

mun

icat

ion

e.

g. h

old

bind

ing

site

s fo

r m

ove

men

t of

org

anel

les

F21

1 M

ark

Sch

em

e Ju

ne

2013

12

(b

)

A1

ph

osp

ho

lipid

s fo

rm b

ilaye

r /d

esc

ribe

d

O

R

pho

spho

lipid

hyd

rop

ho

bic

tai

ls p

oint

ing

inw

ards

and

h

ydro

ph

ilic

head

s po

intin

g ou

t ;

F1

pro

vide

bar

rier

to, l

arge

/ po

lar

/

(nam

ed)

mol

ecul

es O

R io

ns

O

R

d

escr

ibed

;

A2

pro

tein

s fo

rm, p

ore

s /

chan

nel

/ ca

rrie

rs

OR

ex

trin

sic

/ in

trin

sic

/ tra

nsm

emb

ran

e / d

escr

ibed

,

p

rote

ins

; F

2 fo

r (a

ctiv

e) tr

ansp

ort /

co

tran

spo

rt /

f

acili

tate

d d

iffu

sio

n

OR

en

zym

es

;

A3

ch

ole

ster

ol m

olec

ules

fit,

with

in b

ilaye

r / b

etw

een

p

ho

sph

olip

id /

betw

een

fatt

y ac

ids

/ be

twee

n

(p

hosp

holip

id O

R h

ydro

phob

ic)

tails

;

F3

sta

bilis

e m

embr

ane

(str

uctu

re)

/ reg

ulat

es fl

uidi

ty ;

m

ax 4

Mar

k th

e fi

rst

two

co

mp

on

ents

list

ed o

nly

A

war

d m

arks

fo

r su

itab

ly la

bel

led

dia

gra

m(s

) M

ark

po

ints

are

lin

ked

– e

nsu

re t

he

fun

ctio

n m

atch

es

the

com

po

nen

t e.

g. D

O N

OT

CR

ED

IT a

n en

zym

e ar

rang

ed a

s a

chan

nel

prot

ein

AC

CE

PT

pho

spho

lipid

bila

yer

A

CC

EP

T O

RA

– o

nly

allo

w s

mal

l / n

on-p

olar

mol

ecul

es to

pa

ss t

hrou

gh

e.g.

pre

vent

s m

ove

men

t of g

luco

se a

cros

s m

embr

ane

AC

CE

PT

po

re /

cha

nnel

/ ca

rrie

r, p

rote

in

AC

CE

PT

pro

tein

em

bedd

ed in

bila

yer

AC

CE

PT

cor

rect

ref

to m

ove

men

t of (

appr

opria

te)

subs

tanc

e(s)

acr

oss

mem

bran

e

AC

CE

PT

be

twee

n bi

laye

r IG

NO

RE

incr

ease

s flu

idity

/ re

duce

s rig

idity

/ st

reng

then

s /

keep

s it

fluid

F21

1 M

ark

Sch

em

e Ju

ne

2013

13

A4

gly

cop

rote

ins

/ g

lyco

lipid

s ,

on s

urfa

ce /

stic

king

out

fr

om s

urfa

ce, (

of c

ell s

urfa

ce m

embr

ane

) ;

F4

cel

l sig

nal

lin

g /

rece

pto

r si

tes

/ ad

hes

ion

/

an

tig

ens

/ rec

ogni

tion

O

R

sta

bilis

ing

(cel

l sha

pe)

;

Ens

ure

cand

idat

e is

ref

errin

g to

the

sur

face

of a

m

embr

ane

rath

er th

an th

e ce

ll su

rfac

e m

embr

ane

unqu

alifi

ed

CR

ED

IT Id

ea o

f gly

copr

otei

ns /

glyc

olip

ids

on in

ner

surf

ace

or o

uter

sur

face

of (

cell

surf

ace)

mem

bra

ne

IGN

OR

E g

lyco

prot

ein

/ gl

ycol

ipid

s em

bedd

ed in

m

embr

ane

QW

C ;

1

No

te:

on

ly a

war

d t

his

mar

k fo

r te

rms

use

d in

d

escr

ipti

on

of

firs

t tw

o c

om

po

nen

ts –

an

d o

nly

aw

ard

if

giv

en in

co

rrec

t d

escr

ipti

on

as

sho

wn

bel

ow

. aw

ard

if a

ny tw

o te

rms

spel

t cor

rect

ly a

nd u

sed

in c

orr

ect

con

text

from

: fo

r pho

spho

lipid

s ac

cept

: ph

osp

ho

lipid

, bila

yer,

h

ydro

ph

ilic

, hyd

rop

ho

bic

fo

r pro

tein

s ac

cept

: pro

tein

, po

re, c

han

nel

, car

rier

, en

zym

e, in

trin

sic,

ext

rin

sic,

tra

nsm

emb

ran

e,

cotr

ansp

ort

, fac

ilita

ted

dif

fusi

on

fo

r cho

lest

erol

acc

ept:

cho

lest

ero

l, f

atty

aci

d,

ph

osp

ho

lip

id

for g

lyco

prot

ein

/ gly

colip

id a

ccep

t: g

lyco

pro

tein

, g

lyco

lipid

, cel

l sig

nal

(l)i

ng

, rec

epto

r, a

dh

esio

n,

anti

gen

F21

1 M

ark

Sch

em

e Ju

ne

2013

14

(c

) (i

) (p

hosp

holip

id)

bila

yer

;

1

(ii)

(n

amed

) pr

ote

ins

;

1 A

CC

EP

T g

lyco

prot

eins

D

O N

OT

CR

ED

IT c

oenz

ymes

(i

ii)id

ea th

at: f

reez

ing

/ def

rost

ing,

dam

ages

the,

p

erox

isom

e / (

plas

ma)

me

mbr

ane

; in

crea

ses

perm

eabi

lity

of m

embr

ane

to, e

nzym

e / h

ydro

gen

pero

xide

;

mor

e hy

dro

gen

pero

xide

bro

ken

dow

n (s

o m

ore

oxy

gen

rel

ease

d) ;

max

2

eg fo

rmat

ion

of ic

e cr

ysta

ls c

ause

s m

embr

ane

dam

age

/ pe

roxi

som

es

burs

t IG

NO

RE

de

natu

red

for

dam

aged

IG

NO

RE

mem

bran

es b

ecom

e m

ore

leak

y un

qual

ified

A

CC

EP

T r

elea

se e

nzym

e

AC

CE

PT

hyd

roge

n pe

roxi

de /

subs

trat

e, b

roke

n do

wn

at a

hi

gher

rat

e IG

NO

RE

hig

her

rate

of r

eact

ion

unqu

alifi

ed /

high

er r

ate

of

oxyg

en p

rod

uctio

n

To

tal

11

F21

1 M

ark

Sch

em

e Ju

ne

2013

15

6 (a

)

tra

nspi

ratio

n

loss

of w

ater

vap

our

/ eva

pora

tion

of w

ater

;

from

, aer

ial p

arts

of p

lant

/ le

aves

/ st

omat

a ;

tra

nspi

ratio

n st

ream

m

ove

men

t of w

ater

(up

xyl

em v

esse

ls)

; fr

om r

oots

to, l

eave

s / a

ir su

rrou

ndin

g le

aves

;

m

ax 3

IGN

OR

E e

vapo

ratio

n of

wat

er v

apou

r

(b

)

F ;

G

;

K ;

3

Onl

y on

e tic

k pe

r se

t – if

mor

e th

an o

ne ti

ck th

en a

pply

C

ON

IG

NO

RE

cro

sses

and

hyb

rid

cros

ses

(c)

X

ylem

P

hloe

m

(nam

ed)

min

eral

(s)

/ sal

ts

sucr

ose

/ am

ino

acid

s no

, en

d /

cros

s,

wal

ls

ligni

n

(bor

dere

d) p

its

Pla

smod

esm

ata

4

Aw

ard

1 m

ark

for

a co

rrec

t ro

w.

IGN

OR

E io

ns

unqu

alifi

ed /

nutr

ient

s IG

NO

RE

pro

tein

s /

suga

rs /

min

eral

s /

salts

for

phl

oem

D

O N

OT

CR

ED

IT g

luco

se

IGN

OR

E c

ont

inuo

us t

ube

DO

NO

T C

RE

DIT

hol

es

/ por

es

To

tal

10

; ; ; ;

Oxford Cambridge and RSA Examinations is a Company Limited by Guarantee Registered in England Registered Office; 1 Hills Road, Cambridge, CB1 2EU Registered Company Number: 3484466 OCR is an exempt Charity OCR (Oxford Cambridge and RSA Examinations) Head office Telephone: 01223 552552 Facsimile: 01223 552553 © OCR 2013

OCR (Oxford Cambridge and RSA Examinations) 1 Hills Road Cambridge CB1 2EU OCR Customer Contact Centre Education and Learning Telephone: 01223 553998 Facsimile: 01223 552627 Email: general.qualifications@ocr.org.uk www.ocr.org.uk For staff training purposes and as part of our quality assurance programme your call may be recorded or monitored