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8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
1/18
Oxford Cambridge and RSA Examinations
GCE
Biology
Advanced Subsidiary GCE
Unit F211: Cells, Exchange and Transport
Mark Scheme for June 2013
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
2/18
OCR (Oxford Cambridge and RSA) is a leading UK awarding body, providing a wide range ofqualifications to meet the needs of candidates of all ages and abilities. OCR qualificationsinclude AS/A Levels, Diplomas, GCSEs, Cambridge Nationals, Cambridge Technicals,Functional Skills, Key Skills, Entry Level qualifications, NVQs and vocational qualifications inareas such as IT, business, languages, teaching/training, administration and secretarial skills.
It is also responsible for developing new specifications to meet national requirements and theneeds of students and teachers. OCR is a not-for-profit organisation; any surplus made isinvested back into the establishment to help towards the development of qualifications andsupport, 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 requirementsof the examination. It shows the basis on which marks were awarded by examiners. It does notindicate the details of the discussions which took place at an examiners’ meeting before markingcommenced.
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 skillsdemonstrated.
Mark schemes should be read in conjunction with the published question papers and the reporton the examination.
OCR will not enter into any discussion or correspondence in connection with this mark scheme.
© OCR 2013
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
3/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
1
A
n n o t a t i o n s
A v a i l a b l e i n S C O R I S
A n n o t a t i o n
M e a n i n g
B e
n e f i t o f D o u b t
C o
n t r a d i c t i o n
C r o s s
E r r o r C a r r i e d F o r w a r d
G i v e n m a r k
E x
t e n d a b l e h o r i z o n t a l w a v y l i n e
I g n
o r e
Q W
C
B e
n e f i t o f t h e d o u b t n o t g i v e n
a d
d i t i o n a l Q W C c r e d i t g i v e n
T i c
k
T i c
k 1
T i c
k 2
O m
i s s i o n M a r k
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
4/18
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
5/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
3
( c )
m a k e s v i s i b l e / e a s i e r t o s e e / s e e m o r e d e t a i l ;
( s t a i n i n g ) p r o v i d e s / i n c
r e a s e s , c o n t r a s t ;
i d e n t i f y / r e c o g n i s e , c e l l t y p e s / o r g a n e l l e s / p a r t s o f c e
l l ;
i d e n t i f y / r e c o g n i s e , d i f f e r e n t ( n a m e d ) , c o m p o u n d s /
m o l e c
u l e s ;
m a x 2
A C C E P T d i s t i n g u i s h , c e l l s / o r g a n e l l e s , ( f r o m b a c k g r o u n d )
I G N O R E r e f t o c l a r i t y
I G N O R E s u
b s t a n c e s
T o t a l
8
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
6/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
4
Q u e s t
i o n
A n s w e r
M a r k s
G u i d a n c e
2
( a )
( i )
0 . 6 : 1 ; ;
2
C o r r e c t a n s w e r = 2 m a r k s
R a t i o m u s t b e c o r r e c t w a y r o u n d 1 : 0 . 6 i s
n o t c o r r e c t b u t
c a n s t i l l a l l o w
m a r k f o r c o r r e c t w o r k i n g i f s h o w n
I f a n s w e r i n c o
r r e c t A L L O W 1 m a r k f o r w o r k i n g
e . g . 6 0
0 ÷ 1 0 0 0
6 0 0 : 1 0 0 0 =
1 m a r k
( i i )
a s S A : V O L r a t i o d e c r e a s e s r a t e o f d i f f u s i o n d e c r e a s e s
O R
a s S A : V O L r a t i o i n c r e a s e s r a t e o f d i f f u s i o n i n c r e a s e s ;
u s e o f t w o p a i r s o f f i g u r e s w i t h c o r r e c t u n i t s ( m m s - 1 ) f o
r
r a t e t o i l l u s t r a t e t r e n d ;
r e f t o r a t e o f d i f f u s i o n i n
e i t h e r o f t h e f i r s t t w o c u b e s n o t
f i t t i n g t r e n d ;
m a x 2
A C C E P T p o s i t i v e c o r r e l a t i o n
D O N O T C R E
D I T a s r a t e o f d i f f u s i o n d e c r e a
s e s S A : V O L
r a t i o d e c r e a s e
s
u s e o f f i g s r e q
u i r e s r a t i o q u o t e a n d r a t e q u o t e a t t w o p o i n t s
e . g . a t S A : V O L o f 3 : 1 r a t e i s 0 . 0 2 m m s - 1 , a t S
A : V O L r a t i o o f
0 . 2 : 1 r a t e i s 0 . 0 1 3 ( c o r r e c t u n i t s o n l y n e e d t o
b e u s e d o n c e )
D O N O T C R E
D I T i f u n i t f o r S A : V o l g i v e n
A C C E P T c o r r e c t c a l c u l a t i o n o f r a t e c h a n g e
e . g . w h e n t h e
S A : V O L r a t i o w a s 3 : 1 t h e r a t e
o f d i f f u s i o n w a s
0 . 0 2 0 m m s - 1 w
h i c h i s 0 . 0 0 7 m m s - 1 f a s t e r t h a n
t h e c u b e w i t h
0 . 2 : 1 S A : V O L
r a t i o
( i i i )
( l a r g e p l a n t s ) h a v e a , s m a l l / l o w , S A : V O L r a t i o ;
i d e a o f d i f f u s i o n t o o s l o
w ( t o s u p p l y r e q u i r e m e n t s ) ;
i d e a o f n e e d t r a n s p o r t
s y s t e m ( f o r w a t e r / m i n e r a l s /
a s s i m i l a t e s ) ;
i d e a o f n e e d ( s p e c i a l ) s u r f a c e a r e a f o r , g a s e o u s e x c h
a n g e
/ u p t a k e o f m i n e
r a l s ;
m a x 2
D O N O T C R E
D I T s m a l l e r u n l e s s w e k n o w s m a l l e r t h a n w h a t
A C C E P T e . g .
l a r g e r p l a n t s h a v e a s m a l l e r S A : V o l r a t i o
m u s t h a v e i d e
a o f t o o s
l o w
A C C E P T d i f f u
s i o n t a k e s t o o l o n g
D O N O T C R E
D I T t r a n s p o r t o f g a s e s
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
7/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
5
Q u e s t
i o n
A n s w e r
M a r k s
G u i d a n c e
( b )
( i )
d i v i d e d l e n g t h o f s i d e b
y t i m e t a k e n ;
1
I G N O R E d i v i d
e m m b y s ( u n i t s a l o n e t o o v a g
u e )
( i i )
i d e a t h a t s t u d e n t u s e d w h o l e l e n g t h o f s i d e , r a t h e r t h a
n
h a l f l e n g t h ;
1
A C C E P T n e e d s t o d i v i d e a n s w e r b y 2 / d i s t a
n c e h a s t o b e t o
c e n t r e o f c u b e
r a t h e r t h a n w h o l e l e n g t h o f s i d e / a s s u m e d
d i f f u s i o n o c c u r s ( a c r o s s w h o l e c u b e ) f r o m o n
e s i d e
( c )
s q u a m o u s e p i t h e
l i u m
s h o r t ( e r ) d i f f u s i o n , d i s t a
n c e / p a t h ;
l a r g e n u m b e r o f a l v e o l i
l a r g e ( r ) s u r f a c e a r e a ;
g o o d b l o o d s u p p l y
h i g h / l a r g e / s t e e p , c o n
c e n t r a t i o n g r a d i e n t
O R
r e m o v e s o x y g e n ( f r o m
l u n g s u r f a c e ) / b r i n g s c a r b o n
d i o x i d e ( t o l u n g s u r f a c e ) ;
g o o d v e n t i l a t i o n
h i g h / l a r g e / s t e e p , c o n
c e n t r a t i o n g r a d i e n t
O R
s u p p l i e s o x y g e n ( t o a l v e o l i ) / r e m o v e s c a r b o n d i o x i d e
( f r o m a l v e o
l i ) ;
4
A C C E P T r e d u
c e d / s h o r t e r d i f f u s i o n d i s t a n c e
A C C E P T t h i n
d i f f u s i o n b a r r i e r
I G N O R E t h i n d i f f u s i o n p a t h w a y
A C C E P T i n c r e a s e s s u r f a c e a r e a
I G N O R E S A :
V o l r a t i o
A C C E P T m a i n t a i n s / c r e a t e s c o n c e n t r a t i o n g
r a d i e n t
I G N O R E r e f d
i f f u s i o n g r a d i e n t
A C C E P T m a i n t a i n s / c r e a t e s c o n c e n t r a t i o n g
r a d i e n t
I G N O R E r e f d
i f f u s i o n g r a d i e n t
I G N O R E r e f t o a i r
T o t a l
1 2
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
8/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
6
3
( a )
( i )
m i t o s i s / m i t o t i c ;
1
C o r r e c t s p e l l i n
g o n l y
( i i )
f o u r c h r o m o s o m e s o n e q u a t o r ;
( e a c h c h r o m o s o m e a s )
t w o s i s t e r c h r o m a t i d s ;
2
I f t h e i m a g e i s
u n c l e a r t h e n p e n c i l o r a d i f f e r e
n t c o l o u r m a y
h a v e b e e n u s e d - R A I S E A N E X C E P T I O N
A w a r d 2 m a r k
s f o r t h e f o l l o w i n g
D O N O T C R E
D I T m p 1 i f n u c l e a r m e m b r a n e
s h o w n
D O N O T C R E
D I T m p 1 i f h o m o l o g o u s c h r o m
o s o m e s p a i r e d
e . g .
D O N O T C R E
D I T m p 2 i f s i s t e r c h r o m a t i d s a r e n o t j o i n e d ( a t
c e n t r o m e r e )
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
9/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
7
( i i i )
a r r o w f r o m R t o T ;
a r r o w f r o m R t o S A N D
a r r o w f r o m S t o T
O R
a r r o w f r o m R t o S t o T ;
2
e . g .
I f c o n t r a d i c t o r y a r r o w s t o t h e a b o v e a r e d r a w
n , a p p l y C O N
f o r e a c h a r r o w
g o i n g f r o m l o w t o h i g h .
e . g .
g e t s 0
( b )
t h i s i s w h e r e c a m b i u m / m e r i s t e m / x y l e m / p h l o e m /
v a s c u l a r b u n d l e , i s f o u n d ;
m i t o s i s / c e l l d i v i s i o n , o c c u r s i n c a m b i u m ( t o p r o d u c e n e w
c e l l s f o r g r o w t h ) ;
n e w c e l l s , d i f f e r e n t i a t e / s p e c i a l i s e ,
( i n t o x y l e m a n d p h l o e m ) ;
x y l e m s u p p l i e s w a t e r f o
r , ( c e l l ) e l o n g a t i o n / ( c e l l ) g r o w
t h ;
p h l o e m s u p p l i e s , s u g a r s / a s s i m i l a t e s , f o r , e n e r g y / g r o w t h
/ r e s p i r a t i o n ;
m a x 2
C R E D I T f r o m
a l a b e l l e d d i a g r a m
C R E D I T d e s c r i p t i o n o f p o s i t i o n b e i n g c l o s e t o t h e e d g e o f
t r u n k
D O N O T C R E
D I T r e s p o n s e s t h a t s u g g e s t t h a t c a m b i u m e t c .
a r e i n o r o u t s i d e b a r k O R u n d e r c u t s u r f a c e
A C C E P T c a m
b i u m d i f f e r e n t i a t e s
I G N O R E n u t r i e n t s
R
S
T
R
S
T
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
10/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
8
( c )
t i p / a p e x , o f , s h o o t / r o o t ;
m e r i s t e m ;
b u d ;
m a x 1
M a r k t h e f i r s t a n s w e r o n e a c h p r o m p t l i n e
. I f t h e a n s w e r i s
c o r r e c t a n d a n
a d d i t i o n a l a n s w e r i s g i v e n t h a
t i s i n c o r r e c t o r
c o n t r a d i c t s t h e c o r r e c t a n s w e r t h e n = 0 m a r k s
I G N O R E r o o t
o r s h o o t u n q u a l i f i e d
A C C E P T b e h i n d r o o t t i p
( d )
a l l o w o x y g e n t o r e a c h ,
c e l l s / t i s s u e s ( u n d e r b a r k ) ;
f o r ( a e r o b i c ) r e s p i r a t i o n
;
a n i m a l s t r a n s p o r t o x y g e n i n , b l o o d / c i r c u l a t i o n /
t r a n s p o r t s y s t e m ;
p l a n t s d o n o t t r a n s p o r t
( m u c h ) o x y g e n i n t r a n s p o r t
s y s
t e m ;
i d e a t h a t ( o x y g e n n o t s u p p l i e d f r o m l e a v e s a s ) s t o m a t a
o n l y o p e n i n d a y / n o l e a v e s i n w i n t e r ;
m a x 2
I G N O R E r e f s
t o n e e d f o r C O 2 / p h o t o s y n t h e s
i s t h r o u g h o u t
A C C E P T c o r r e c t f o r m u l a O 2
D O N O T C R E
D I T o x y g e n f o r p h o t o s y n t h e s i s
A C C E P T g a s ( e s ) f o r o x y g e n
A C C E P T g a s ( e s ) f o r o x y g e n
T o t a l
1 0
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
11/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
9
Q u e s t
i o n
A n s w e r
M a r k s
G u i d a n c e
4
( a )
( i )
1 p l a c e n t a h a s l o w p O 2 ;
2 a d u l t ( o x y ) h a e m o g l o b i n w i l l , r e l e a s e O 2 / d i s s o c i a t e ,
( i n , l o w p O 2 / p l a c e n
t a ) ;
3 f e t a l h a e m o g l o b i n h a
s h i g h e r a f f i n i t y f o r o x y g e n /
d e s c r i b
e d ;
4 f e t a l h a e m o g l o b i n , i s
( s t i l l ) a b l e t o t a k e u p
( s o m e ) o
x y g e n , i n p l a c e n t a / a t l o w ( e r ) p O 2 ;
m a x 3
A C C E P T o x y g e n t e n s i o n f o r p O 2 t h r o u g h o u t
I G N O R E
l o w e r
T h i s m u s t b e a c o m p a r a t i v e s t a t e m e n t
C R E D I T I d e a
t h a t f e t a l h a e m o g l o b i n p i c k s u p m o r e o x y g e n
t h a n t h e a d u l t
h a e m o g l o b i n a t a g i v e n p O 2 /
f e t a l h a e m o g l o b i n p i c k s u p o x y g e n a t l o w e r p
O 2
I G N O R E r e f t o e a s i e r / q u i c k e r , u p t a k e o f O 2
T h i s i s n o t a c
o m p a r a t i v e p o i n t , t h e e m p h a s i s i s o n t h e a b i l i t y
o f f e t a l h a e m o
g l o b i n t o t a k e u p s o m e o x y g e n
e v e n w h e n l i t t l e
i s a v a i l a b l e
D O N O T C R E
D I T i f r e s p o n s e s u g g e s t s t h a t % s a t u r a t i o n
i n c r e a s e s a s p
O 2 d e c r e a s e s
A C C E P T f e t a l o x y h a e m o g l o b i n
( i i )
( f e t a l ) h a e m o g l o b i n m a y n o t c r y s t a l l i s e ( m u c h )
( a t l o w p
O 2 ) ;
r e d b l o o d c e l l s d o n o t c
h a n g e s h a p e ;
( f e t a l ) h a e m o g l o b i n c a n
p i c k u p m o r e o x y g e n a t l o w p O 2
( t h a n s i c k l e h a e m o g l o
b i n ) ;
i d e a t h a t m o r e o x y g e n ,
t r a n s p o r t e d / d e l i v e r e d
( a r o u n d b o
d y ) ;
m a x 2
a s s u m e c a n d i d a t e r e f e r s t o f e t a l h a e m o g l o b i n u n l e s s a d u l t /
m a t e r n a l s t a t e
d
E m p h a s i s f o r t h i s m p i s t h e f e t a l h a e m o g l o b i n b e i n g a b l e t o
p i c k u p m o r e o x y g e n t h a n s i c k l e h a e m o g l o b i n
C R E D I T ( f e t a l ) h a e m o g l o b i n b e c o m e s m o r e
s a t u r a t e d a t
l o w p O 2 ( t h a n
s i c k l e h a e m o g l o b i n )
A l l o w r e f t o l o w e r p O 2 u n l e s s i t i s i m p l i e d t h a t f e t a l
h a e m o g l o b i n p i c k s u p m o r e o x y g e n a t l o w e r
p O 2 t h a n
h i g h e r p O 2
E m p h a s i s f o r t h i s m p i s t h e d i s t r i b u t i o n o f o x y g e n
I G N O R E m o r e o x y g e n o b t a i n e d b y p e r s o n ( a
s t h i s i m p l i e s
b r e a t h i n g )
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
12/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
1 0
( b )
d i f f u s i o n ;
f r o m h i g h c o n c e n t r a t i o n
t o l o w c o n c e n t r a t i o n / d o w n
c o n c e n t r a t i o n g r a d
i e n t ;
( h y d r o s t a t i c ) p r e s s u r e i n c a p i l l a r y h i g h ( e r t h a n i n t i s s u e
f l u i d ) ;
c a p i l l a r y ( w a l l s ) l e a k y /
d e s c r i b e d ;
f l u i d / p l a s m a , f o r c e d o u t ( o f c a p i l l a r y )
O R f l u i d / p l a s m a , m o v e s , f r o m h i g h e r p r e s s u r e t o l o w e r
p r e s s u r e / d o w n p r e s s u r e g r a d i e n t ;
( a s t h e f l u i d / p l a s m a m
o v e s o u t ) g l u c o s e / o x y g e n / s m a l l
m o l e c u l e s , l e a v e w i t h , f l u i d / p l a s m a ;
m a x 3
I G N O R E d i f f u s i o n o f g l u c o s e t h r o u g h o u t a n s
w e r
‘ d o w n d i f f u s i o n g r a d i e n t ’ = 1 f o r ‘ d i f f u s i o n ’ ( m
p 1 n o t m p 2 )
D O N O T C R E
D I T d i f f u s i o n l i n k e d t o p r e s s u r e
A C C E P T p O 2 f o r c o n c e n t r a t i o n
A C C E P T p e r m
e a b l e
I G N O R E
p o r e s / f e n e s t r a t i o n s / h o l e s
A C C E P T i d e a
o f s m a l l g a p s b e t w e e n c e l l s
E m p h a s i s h e r e i s o n p r e s s u r e f o r c i n g f l u i d o u t
D O N O T C R E
D I T t i s s u e f l u i d f o r c e d o u t
E m p h a s i s h e r e i s o n g l u c o s e / o x y g e n b e i n g
c a r r i e d o u t a s a
r e s u l t o f m a s s
f l o w o f f l u i d ( n o t d i f f u s i o n )
Q W C ;
1
a w a r d i f a n y t w o t e r m s s p e l t c o r r e c t l y a n d u s
e d i n c o r r e c t
c o n t e x t f r o m :
d i f f u s i o n / d i f f u s e , p r e s s u r e , h y d r o s t a t i c ,
c o n c e n t r a t i o n g r a d i e n t
T o t a l
9
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
13/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
1 1
Q u e s t
i o n
A n s w e r
M a r k s
G u i d a n c e
5
( a )
f o r m s , v e s i c l e s / ( n a m e
d ) o r g a n e l l e ( s ) ;
s e p a r a t e ( c o n t e n t s o f ) o r g a n e l l e s f r o m c y t o p l a s m /
c o m p a r t m e n t a l i s a t i o n ;
s i t e o f ( n a m e d ) , p r o c e s
s e s / r e a c t i o n s ;
p r o v i d e s s u r f a c e f o r a t t a c h m e n t ( o f e n z y m e s / r i b o s o m
e s ) ;
c o n t r o l w h a t s u b s t a n c e
s , e n t e r / l e a v e , o r g a n e l l e s ;
A V P ;
m a x 2
A C C E P T t r
a n s p o r t i n v e s i c l e s
e . g . i s o l a t e s D N A f r o m c y t o p l a s m / s e p a r a
t e d i f f e r e n t
e n v i r o n m e n
t s / s e p a r a t e o r g a n e l l e s
e . g . l y s o s o m e s i s o l a t e e n z y m e s ( a n d p r e v
e n t d a m a g e
t o c e l l s )
e . g . s e p a r a
t e s ( m e t a b o l i c ) r e a c t i o n s
I G N O R E a n y r e f t o n u c l e a r p o r e s
D O N O T C R E D I T s u b s t a n c e s , e n t e r / l e a v
e , c e l l s
e . g . a l l o w c
r e a t i o n o f c o n c e n t r a t i o n g r a d i e
n t s
e . g . r e f t o i n
t r a c e l l u l a r c o m m u n i c a t i o n
e . g . h o l d b i n d i n g s i t e s f o r m o v e m e n t o f o r g a n e l l e s
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
14/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
1 2
( b )
A 1 p h o s p h o l i p i d s f o r m b i l a y e r / d e s c r i b e d
O R
p h o s p h o l i p i d h y d r o p h o b i c t a i l s p o i n t i n g i n w a r d s
a n d
h y d r o p h i l i c h e a d s p o i n t i n g
o u t ;
F 1 p r o v i d e b a r r i e r t o , l a r g e / p o l a r /
( n a m e d ) m o l e c u l e s O
R i o n s
O R
d e s c r i b e d ;
A 2 p r o t e i n s f o r m , p o r
e s / c h a n n e l / c a r r i e r s
O R
e x t r i n s i c / i n t r i n s i c / t r a n s m e m b r a n e / d e s c r i b e d ,
p r o t e i n s ;
F 2 f o r ( a c t i v e ) t r a n s p o r t / c o t r a n s p o r t /
f a c i l i t a t e d d i f f u s i o n
O R
e n z y m e s ;
A 3 c h o l e s t e r o l m o l e c u l e s f i t , w i t h i n b i l a y e r / b e t w e e n
p h o s p h o l i p i d / b e t w e e n f a t t y a c i d s / b e
t w e e n
( p h o s p h o l i p i d O R h y d r o p h o b i c ) t a i l s ;
F 3 s t a b i l i s e m e m b r a n e
( s t r u c t u r e ) / r e g u l a t e s f l u i d i t y ;
m a x 4
M a r k t h e f i r s t t w o c o m p o n e n t s l i s t e d o n l y
A w a r d m a r k s f o r s u i t a b l y l a b e l l e d d i a g r a m ( s )
M a r k p o i n t s a r e l i n k e d – e n s u r e t h e f u n
c t i o n m a t c h e s
t h e c o m p o
n e n t
e . g . D O N O
T C R E D I T a n e n z y m e a r r a n g e
d a s a c h a n n e l
p r o t e i n
A C C E P T p h o s p h o l i p i d b i l a y e r
A C C E P T O
R A – o n l y a l l o w s m a l l / n o n - p o
l a r m o l e c u l e s t o
p a s s t h r o u g
h
e . g . p r e v e n
t s m o v e m e n t o f g l u c o s e a c r o s s m e m b r a n e
A C C E P T p o r e / c h a n n e l / c a r r i e r , p r o t e i n
A C C E P T p r o t e i n e m b e d d e d i n b i l a y e r
A C C E P T c o r r e c t r e f t o m o v e m e n t o f ( a p p r o p r i a t e )
s u b s t a n c e ( s ) a c r o s s m e m b r a n e
A C C E P T b e t w e e n b i l a y e r
I G N O R E i n
c r e a s e s f l u i d i t y / r e d u c e s r i g i d i t y / s t r e n g t h e n s /
k e e p s i t f l u i d
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15/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
1 3
A 4 g l y c o p r o t e i n s / g l y c o l i p i d s , o n s u r f a c e / s t i c k i n g o u t
f r o m s u r f a c e , ( o f c e l l s u
r f a c e m e m b r a n e ) ;
F 4 c e l l s i g n a l l i n g / r e c e p t o r s i t e s / a d h e s i o n /
a n t i g e n s / r e c o g n i t i o n
O R
s t a b i l i s i n g ( c e l l s h a
p e ) ;
E n s u r e c a n
d i d a t e i s r e f e r r i n g t o t h e s u r f a c
e o f a
m e m b r a n e
r a t h e r t h a n t h e c e l l s u r f a c e m e
m b r a n e
u n q u a l i f i e d
C R E D I T I d e a o f g l y c o p r o t e i n s / g l y c o l i p i d s
o n i n n e r
s u r f a c e o r o
u t e r s u r f a c e o f ( c e l l s u r f a c e ) m
e m b r a n e
I G N O R E g l y c o p r o t e i n / g l y c o l i p i d s e m b e d d e d i n
m e m b r a n e
Q W C ;
1
N o t e : o n l y
a w a r d t h i s m a r k f o r t e r m s u
s e d i n
d e s c r i p t i o n o f f i r s t t w o c o m p o n e n t s – a
n d o n l y a w a r d
i f g i v e n i n
c o r r e c t d e s c r i p t i o n a s s h o w n b e l o w .
a w a r d i f a n
y t w o t e r m s s p e l t c o r r e c t l y a n d
u s e d i n c o r r e c t
c o n t e x t f r o
m :
f o r p h o s p h o
l i p i d s a c c e p t : p h o s p h o l i p i d , b
i l a y e r ,
h y d r o p h i l i c , h y d r o p h o b i c
f o r p r o t e i n s
a c c e p t : p r o t e i n , p o r e , c h a n n e l , c a r r i e r ,
e n z y m e , i n
t r i n s i c , e x t r i n s i c , t r a n s m e m b
r a n e ,
c o t r a n s p o r t , f a c i l i t a t e d d i f f u s i o n
f o r c h o l e s t e
r o l a c c e p t : c h o l e s t e r o l , f a t t y a c i d ,
p h o s p h o l i p i d
f o r g l y c o p r o
t e i n / g l y c o l i p i d a c c e p t : g l y c o p
r o t e i n ,
g l y c o l i p i d ,
c e l l s i g n a l ( l ) i n g , r e c e p t o r , a d
h e s i o n ,
a n t i g e n
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
16/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
1 4
( c )
( i )
( p h o s p h o l i p i d ) b i l a y e r ;
1
( i i )
( n a m e d ) p r o t e i n s ;
1
A C C E P T g l y c o p r o t e i n s
D O N O T C R E D I T c o e n z y m e s
( i i i )
i d e a t h a t : f r e e z i n g / d e f r o s t i n g , d a m a g e s t h e ,
p e r o x i s o m e / ( p l a s m a ) m e m b r a n e ;
i n c r e a s e s p e r m e a b i l i t y
o f m e m b r a n e t o , e n z y m e / h y d
r o g e n
p e r o x i d e ;
m o r e h y d r o g e n p e r o x i d
e b r o k e n d o w n ( s o m o r e o x y g e n
r e l e a s
e d ) ;
m a x 2
e g f o r m a t i o
n o f i c e c r y s t a l s c a u s e s m e m b r a n e d a m a g e /
p e r o x i s o m e
s b u r s t
I G N O R E d e n a t u r e d f o r d a m a g e d
I G N O R E m
e m b r a n e s b e c o m e m o r e l e a k y
u n q u a l i f i e d
A C C E P T r e
l e a s e e n z y m e
A C C E P T h y d r o g e n p e r o x i d e / s u b s t r a t e , b
r o k e n d o w n a t a
h i g h e r r a t e
I G N O R E h i g h e r r a t e o f r e a c t i o n u n q u a l i f i e
d / h i g h e r r a t e o f
o x y g e n p r o d u c t i o n
T o t a l
1 1
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
17/18
F 2 1 1
M a r k S c h e m e
J u n e 2 0 1 3
1 5
6
( a )
t r a n s p i r a t i o n
l o s s o f w a t e r v a p o u r / e
v a p o r a t i o n o f w a t e r ;
f r o m , a e r i a l p a r t s o f p l a
n t / l e a v e s / s t o m a t a ;
t r a n s p i r a t i o n s t r e a m
m o v e m e n t o f w a t e r ( u p
x y l e m v e s s e l s ) ;
f r o m r o o t s t o , l e a v e s / a
i r s u r r o u n d i n g l e a v e s ;
m a x 3
I G N O R E e v a p o r a t i o n o f w a t e r v a p o u r
( b )
F ; G ; K ;
3
O n l y o n e t i c k p e r s e t – i f m o r e t h a n o n e t i c
k t h e n a p p l y
C O N
I G N O R E c r
o s s e s a n d h y b r i d c r o s s e s
( c )
X y l e m
P h l o e m
( n a m e d ) m i n
e r a l ( s )
/ s a l t s
s u c r o s e / a m i n o
a c i d s
n o , e n d / c r o s s ,
w a l l s
l i g n i n
( b o r d e r e d ) p i t s
P l a s m o d e s m a t a
4
A w a r d 1 m
a r k f o r a c o r r e c t r o w .
I G N O R E i o
n s u n q u a l i f i e d / n u t r i e n t s
I G N O R E p r o t e i n s / s u g a r s / m i n e r a l s / s a l t s f o r p h l o e m
D O N O T C R E D I T g l u c o s e
I G N O R E c o
n t i n u o u s t u b e
D O N O T C R E D I T h o l e s / p o r e s
T o t a l
1 0
; ; ; ;
8/9/2019 176038 Mark Scheme Unit f211 Cells Exchange and Transport June
18/18
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