Jan 2006 U6

1.

(a)

(b)

(c)

1.

Concentration of monosaccharide decreases, lipids increase;

2.

Reference to greater change in monosaccharide;

3.

From 60 minutes, concentration of lipid remains higher than monosaccharide;

4.

Both level out {after 240 minutes / eq};

5.

Credit manipulated, quantitative comparison;

1.

Monosaccharides used as an energy source / eq;

2.

At start / eq (of flight);

3.

Used up quickly / eq;

4.

Lipid concentration increases as removed from stores / eq;

5.

Lipid used as a substrate after monosaccharide;

6.

Idea that Lipids are slower to be [mobilised / metabolised eq};

3

3

Glycogen converted to {monosaccharide / glucose}; {Monosaccharides / glucose} used for {energy / respiration flight muscle contraction}

2 [8]

2.

(a)

Third / tertiary (trophic level) / secondary consumers / carnivores;

(b)

(i)

(ii)

(c)

(i)

1.

Birds that hatched earlier have a higher chance of survival / eq (or converse);

2.

Greatest drop in survival 10th to 20th May;

3.

Then steady decrease / eq;

4.

Credit comparative use of figures;

1.

More food available early in the season / converse;

2.

Less competition for food / converse;

3.

Fewer predators / converse;

4.

Ref. to temperature change;

(iii)

3

2

Survival rate at 15 days for mean mass of 21 g (from Graph 2) = 18 % Number of birds surviving = 18 × (8  100); [or equivalent calculation] = 1 ; [accept c. e.]

(ii)

1

1.

They have more food reserves / energy stores;

2.

Grow faster(in future);

3.

More muscle development;

4.

More feathers;

5.

Able to escape from predators / eq;

6.

Smaller surface area to volume ratio;

7.

Better temperature control / eq;

8. Reference to competition; Birds with greatest mass;

2006 Jan Module 6 MS

3

2

1

(and) hatched earlier in breeding season; (d)

1.

Less heat loss;

2.

Protection from predators / eq;

3.

Less chance of fatting out of nest / nest may fall off branch;

4.

Need fewer nest building materials;

5.

Reference to protection from weather / eq;

2

2 [15]

3.

Units 2 & 5 Introduction could include reference to the importance of genetic variation – Sexual reproduction involves fusion of gametes leading to genetic variation – Gamete formation involves reduction division (meiosis) – Behaviour of chromosomes during first and second divisions of meiosis – Chiasmata formation – Crossing over – Units 1 & 5 Autosomal linkage and recombinants in relation to events of meiosis – Significance of mutations – Causes of mutations, chemical mutagens and radiation – Point mutations – Chromosome mutations – Translocation – Polysomy – Polyploidy – Scientific content 11 marks Balance 2 marks Coherence 2 marks Total 15 marks

ESSAY MARK SCHEME Total maximum mark available: 15 11 available for Scientific content 2 available for Balance 2 available for Coherence

2006 Jan Module 6 MS

2

Scientific content (S) Scientific content (S)

Description

11 (good)

The essay demonstrates a sound understanding of the topic, contains a significant amount of material relevant to two (or more) Units(including A2 units) of the specification, and includes suitable examples where appropriate. The candidate has clearly and coherently linked together information from different parts of the specification.

9 (above average)

An above average essay, with accurate content. The essay includes a good balance of material from two (or more) Units(including the A2 units), and examples where appropriate. There may be some minor factual errors.

7 (average)

The essay includes relevant information from two (or more) Units(including A2 units), and the candidate links together some facts and principles. Some examples are included. There may be some minor factual errors.

5 (below average)

The essay includes some generally factually accurate and relevant material, and there is some attempt to link material from more than one Unit. However, the discussion lacks details, particularly of A2 Units.

3 (poor)

There are some correct facts, but the essay lacks depth and accuracy. Little or no relevant information from A2 Units is included.

1 (poor)

There are very few correct facts. The essay is generally superficial and inaccurate.

0 (poor)

No correct, or relevant, information included.

Note: If a scientific content mark of 0, 1, or 3 is awarded, it is very unlikely that a balance mark of more than 1 is appropriate. S = 11 marks

Balance(b) 2

Most of the main topic areas outlined are covered Some discussion of each of the areas chosen, illustrated with suitable examples where appropriate Material included is all relevant to the topic and the candidate has linked information from more than one area of the specification. Few, if any, errors

1

Some of the main topic areas outlined are covered. Some discussion of each of the areas chosen. Some irrelevant material included. There are some examples which link together different areas of the specification. Some errors

0

Very limited account, possibly only one aspect chosen Material mostly irrelevant No examples of the candidate linking information from different topics Large number of errors B = 2 marks

2006 Jan Module 6 MS

3

Coherence(c) 2

Material logically presented, with little or no repetition Essay has coherence, ideas are developed well; continuous prose used throughout Essay has an introduction and a conclusion, summing up the main points Technical terms have been used correctly Spelling, punctuation and grammar are sound

1

Material is presented in an orderly way and some ideas developed Continuous prose used throughout The introduction and conclusion may be present, but brief Technical terms are used and generally in the correct context Spelling, punctuation and grammar are generally sound

0

Essay style not used Material in note form or numbered points Very poor standard of spelling, punctuation and grammar C = 2 marks

4.

Units 2 & 5B Introduction could include relationship between structure and function of a leaf – External and internal structure of a mesophyte leaf – Upper and lower epidermis, palisade mesophyll, spongy mesophyll – Xylem – Phloem – Structure and roles of stomata – Units 1, 3 & 5B Effect of light intensity on photosynthesis – Effect of wavelength on photosynthesis – Effect of carbon dioxide concentration – Effect of temperature – Effect of air pollution – Concept of limiting factors – Compensation point – Scientific content 11 marks Balance 2 marks Coherence 2 marks Total 15 marks

ESSAY MARK SCHEME Total maximum mark available: 15 11 available for Scientific content 2 available for Balance 2 available for Coherence

2006 Jan Module 6 MS

4

Scientific content (S) Scientific content (S)

Description

11 (good)

The essay demonstrates a sound understanding of the topic, contains a significant amount of material relevant to two (or more) Units(including A2 units) of the specification, and includes suitable examples where appropriate. The candidate has clearly and coherently linked together information from different parts of the specification.

9 (above average)

An above average essay, with accurate content. The essay includes a good balance of material from two (or more) Units(including the A2 units), and examples where appropriate. There may be some minor factual errors.

7 (average)

The essay includes relevant information from two (or more) Units(including A2 units), and the candidate links together some facts and principles. Some examples are included. There may be some minor factual errors.

5 (below average)

The essay includes some generally factually accurate and relevant material, and there is some attempt to link material from more than one Unit. However, the discussion lacks details, particularly of A2 Units.

3 (poor)

There are some correct facts, but the essay lacks depth and accuracy. Little or no relevant information from A2 Units is included.

1 (poor)

There are very few correct facts. The essay is generally superficial and inaccurate.

0 (poor)

No correct, or relevant, information included.

Note: If a scientific content mark of 0, 1, or 3 is awarded, it is very unlikely that a balance mark of more than 1 is appropriate. S = 11 marks

Balance(b) 2

Most of the main topic areas outlined are covered Some discussion of each of the areas chosen, illustrated with suitable examples where appropriate Material included is all relevant to the topic and the candidate has linked information from more than one area of the specification. Few, if any, errors

1

Some of the main topic areas outlined are covered. Some discussion of each of the areas chosen. Some irrelevant material included. There are some examples which link together different areas of the specification. Some errors

0

Very limited account, possibly only one aspect chosen Material mostly irrelevant No examples of the candidate linking information from different topics Large number of errors B = 2 marks

2006 Jan Module 6 MS

5

Coherence(c) 2

Material logically presented, with little or no repetition Essay has coherence, ideas are developed well; continuous prose used throughout Essay has an introduction and a conclusion, summing up the main points Technical terms have been used correctly Spelling, punctuation and grammar are sound

1

Material is presented in an orderly way and some ideas developed Continuous prose used throughout The introduction and conclusion may be present, but brief Technical terms are used and generally in the correct context Spelling, punctuation and grammar are generally sound

0

Essay style not used Material in note form or numbered points Very poor standard of spelling, punctuation and grammar C = 2 marks

5.

Units 1 & 5 Introduction could include an outline structure of DNA and methods for dating or investigating relationships Unit 1 Basic structure of a mononucleotide – Purine and pyrimidine bases – DNA as a polynucleotide – Base pairing and the double helix – Unit 5H DNA-DNA hybridisation – Comparison of base sequences – Amino acid sequences – Immunological studies of blood sera – Credit specific examples such as haemoglobin or cytochrome structure – Scientific content 11 marks Balance 2 marks Coherence 2 marks Total 15 marks

ESSAY MARK SCHEME Total maximum mark available: 15 11 available for Scientific content 2 available for Balance 2 available for Coherence

2006 Jan Module 6 MS

6

Scientific content (S) Scientific content (S)

Description

11 (good)

The essay demonstrates a sound understanding of the topic, contains a significant amount of material relevant to two (or more) Units(including A2 units) of the specification, and includes suitable examples where appropriate. The candidate has clearly and coherently linked together information from different parts of the specification.

9 (above average)

An above average essay, with accurate content. The essay includes a good balance of material from two (or more) Units(including the A2 units), and examples where appropriate. There may be some minor factual errors.

7 (average)

The essay includes relevant information from two (or more) Units(including A2 units), and the candidate links together some facts and principles. Some examples are included. There may be some minor factual errors.

5 (below average)

The essay includes some generally factually accurate and relevant material, and there is some attempt to link material from more than one Unit. However, the discussion lacks details, particularly of A2 Units.

3 (poor)

There are some correct facts, but the essay lacks depth and accuracy. Little or no relevant information from A2 Units is included.

1 (poor)

There are very few correct facts. The essay is generally superficial and inaccurate.

0 (poor)

No correct, or relevant, information included.

Note: If a scientific content mark of 0, 1, or 3 is awarded, it is very unlikely that a balance mark of more than 1 is appropriate. S = 11 marks

Balance(b) 2

Most of the main topic areas outlined are covered Some discussion of each of the areas chosen, illustrated with suitable examples where appropriate Material included is all relevant to the topic and the candidate has linked information from more than one area of the specification. Few, if any, errors

1

Some of the main topic areas outlined are covered. Some discussion of each of the areas chosen. Some irrelevant material included. There are some examples which link together different areas of the specification. Some errors

0

Very limited account, possibly only one aspect chosen Material mostly irrelevant No examples of the candidate linking information from different topics Large number of errors B = 2 marks

2006 Jan Module 6 MS

7

Coherence(c) 2

Material logically presented, with little or no repetition Essay has coherence, ideas are developed well; continuous prose used throughout Essay has an introduction and a conclusion, summing up the main points Technical terms have been used correctly Spelling, punctuation and grammar are sound

1

Material is presented in an orderly way and some ideas developed Continuous prose used throughout The introduction and conclusion may be present, but brief Technical terms are used and generally in the correct context Spelling, punctuation and grammar are generally sound

0

Essay style not used Material in note form or numbered points Very poor standard of spelling, punctuation and grammar C = 2 marks

2006 Jan Module 6 MS

8