Jan 2006 W2

1.

(a) Leaf number

Leaf area / mm2

Total indentation depth / mm

12

173

23

4

184

19

11

193

20

7

194

33

10

198

34

6

211

31

8

213

28

3

245

44

1

271

42

5

277

40

9

278

36

2

306

54

[shaded column optional] 1.

Neat table correctly formatted;

2.

Correct rows and columns with units;

3.

Leaf area ranked(ascending or descending);

4.

All totals correct;

(b)

A

(correctly orientated) and labelled axes with units;

S

Scale correct and suitable size (more than ½ graph paper);

P

Plotted points correct;

F

Format correct scatter graph without line or if line drawn must be good line of best fit;

(c)

(d)

4

4

Correct substitution or stage in calculation 1 – (6 × 44)  (123 - 12) OR 1 – (264  1716); Correct answer is 0.85 / 0.846

2

There is a significant positive correlation between leaf area and degree of indentation;

1 [11]

W2 Jan 2006 MS

1

2.

(a)

Estimating squirrel population 1.

Traps laid in wood in random manner described;

2.

Reference to humane treatment of squirrels / unharmed by traps / marking inconspicuous / eq;

3.

How captured squirrels marked / non-toxic dye / shave off patch of fur / eq;

4.

Marked animals counted and released;

5.

Traps inspected again after suitable time (1-2 days);

6.

Number marked and unmarked counted;

7.

Details of calculation: no. marked 1st sample  total trapped in 2nd sample ; N no. marked in 2 nd sample [accept from part(b)] Estimating acorn numbers

8.

Use of quadrats of stated size (0.5 m > 1.0 m);

9.

Number of measurements (minimum 10);

10.

Method of randomisation described (not thrown);

11.

Numbers of acorns in each quadrat counted;

12.

Counts repeated at exactly the same time of year (not just Autumn);

Style

10

Account is concise and well-organised, there is good use of technical vocabulary and almost no spelling errors -2 marks There is some lack of organisation, limited vocabulary and a number of spelling errors –1 mark The account lacks organisation, there is little or no technical vocabulary and many spelling errors – 0 marks

(b)

1.

Table with organisation for all raw data with units;

2.

Reference to calculation of mean acorn count;

3.

Suitable graphical format (scatter or line of best fit) with correctly orientated axes;

4.

Use of (named) correlation test; [details of Lincoln Index calculation to be credited in plan]

W2 Jan 2006 MS

2

4

2

(c)

Limitations 1.

Squirrels eat other foods than acorns / other animals eat acorns;

2.

Reference to one limitation of Lincoln Index method(assumes random mixing of population / marking may affect individuals / eq);

3.

Other named factor may affect population size (e.g. harsh winter / predators immigration / emigration);

4.

Acorns may not be randomly spread / oak trees may be concentrated in one area / eq; Further work

5.

Estimate abundance of other possible food supplies;

6.

Check age profile of squirrels;

7.

Investigate areas where red and grey squirrels are present;

8.

Investigate variations in acorn abundance throughout the year;

5 [21]

W2 Jan 2006 MS

3