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GENERAL CERTIFICATE OF EDUCATION
TYSTYSGRIF ADDYSG GYFFREDINOL




MARKING SCHEME



BIOLOGY/HUMAN BIOLOGY (NEW)
AS/Advanced

JANUARY 2009

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INTRODUCTION

The marking schemes which follow were those used by WJEC for the January 2009
examination in GCE BIOLOGY/HUMAN BIOLOGY. They were finalised after detailed
discussion at examiners' conferences by all the examiners involved in the assessment. The
conferences were held shortly after the papers were taken so that reference…

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AS MODULE BY1
Question Answers/Explanatory Notes Marks
Available
1. (a) F / calcium or G / phosphate
(b) I / sucrose

(c) A / magnesium

(d) D / cellulose

(e) G / phosphate

(f) H / water
(mark first answer) [1 mark each] [Total 6 marks]

2. (a)

Level of…

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Question Answers/Explanatory Notes Marks
Available

3. (d) long chains cross linked by hydrogen bonds;

adjacent glucose molecules are rotated by 180º;

hydrogen bonds form between hydroxyl groups of adjacent parallel chains;

microfibrils. [2]

(not: fibres/fibrils) [Any 2]

[Total 6 marks]


4. (a)

Structure Name Function
A Mitonchondrion (Cell) respiration /…

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Question Answers/Explanatory Notes Marks
Available

5. (c) (i) P = diffusion Q = facilitated diffusion (must have both) [1]

(ii) facilitated diffusion causes more rapid movement of

molecules through a membrane than simple diffusion;

it relies on protein carriers / channel proteins;

and the rate is limited by the number…

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Question Answers/Explanatory Notes Marks
Available

6. (a) (i) A competitive [1]

B non competitive [1]

(ii) A [1]

(b) (i) 5°C kinetic energy is low / few collisions between the (active site)

of the enzyme and the substrate; [1]
Allow: ref. to increasing temp and kinetic energy i.e. assume 0…

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Question Answers/Explanatory Notes Marks
Available

7. (a) (i) metaphase [1]

(ii) centromere [1]

(iii) pulls chromatids/chromosomes to opposite poles [1]

(b)
Statement Stage in cell cycle
Chromosomes shorten and thicken Prophase
and spindle forms
A period of intense activity which interphase
includes the replication of DNA
Formation of two nuclei…

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Question Answers/Explanatory Notes Marks
Available

8. (a) (i) A DNA is a polymer of many nucleotides / nucleotide chains /
polynucleotide; [1]

B The nucleotide contain the (5-carbon sugar / pentose sugar)
deoxyribose; [1]

C Attached to which is a base, either thymine, cytosine, adenine
or guanine; [1]

D The…

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Question Answers/Explanatory Notes Marks
Available

8. (b) A water is a polar molecule / dipolar / allows chemical reactions to
to take place in solution; [1]

B explanation of dipolar H +ve, O ­ve (allows diagram); [1]

C explanation of hydrogen bonding; [1]

D water is an universal solvent /…

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WJEC
245 Western Avenue
Cardiff CF5 2YX
Tel No 029 2026 5000
Fax 029 2057 5994
E-mail: [email protected]
website: www.wjec.co.uk/exams.html

Comments

11LAmbes1234

Do you have the grade boundaries at all ??? 

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