c
N02/410/H(2)
IB DIPLOMA PROGRAMME PROGRAMME DU DIPLÔME DU BI PROGRAMA DEL DIPLOMA DEL BI
Name
BIOLOGY HIGHER LEVEL PAPER 2
Number Wednesday 13 November 2002 (afternoon) 2 hours 15 minutes
INSTRUCTIONS TO CANDIDATES ! ! ! !
!
Write your candidate name and number in the boxes above. Do not open this examination paper until instructed to do so. Section A: Answer all of Section A in the spaces provided. Section B: Answer two questions from Section B. Write your answers in a continuation answer booklet, and indicate the number of booklets used in the box below. Write your name and candidate number on the front cover of the continuation answer booklets, and attach them to this question paper using the tag provided. At the end of the examination, indicate the numbers of the Section B questions answered in the boxes below.
QUESTIONS ANSWERED SECTION A
EXAMINER
TEAM LEADER
IBCA
ALL
/32
/32
/32
QUESTION QUESTION
......... .........
/20
/20
/20
/20
/20
/20
NUMBER OF CONTINUATION BOOKLETS USED
.........
SECTION B
882-135
TOTAL
TOTAL /72
TOTAL /72
/72
9 pages
–2–
N02/410/H(2)
SECTION A Candidates must answer all questions in the spaces provided. 1.
Seed dispersal is important in the migration of plants from one area to another area. Plants have evolved many methods, both physical and biological, by which to disperse their seeds. 50 maple seeds, which are wind dispersed, were dropped one at a time from two different heights, 0.54 m and 10.8 m respectively. The histograms below show the distribution of the distance the maple seeds travelled. 18
18
17
16
Height = 0.54 m
15
14
14
12
12
10
10
Number 8 of seeds 6
Number 8 of seeds 6
5
4
3
3
1
Height = 10.8 m
9 7 5
4
4
3
3
2
1
1
Distance travelled / cm
11 .9 1 15 4.9 to 1 18 7.9 to 20 . 21 9 to 24 ov er 24 to
12
8. 9 9
to
to
5. 9 6
to 3
to
to 20 19 to 40 39 to 60 59 to 80 79 10 to 9 9 0 to 12 11 9 0 to 14 13 9 0 to 16 15 9 0 to 18 17 9 0 to 20 0
0
2. 9
0
0
0
2
2
4
17
16
Distance travelled / m
[Source: student experiment, Guralnick]
(a)
(b)
For each height, identify the distance travelled by the greatest number of seeds. (i)
Height = 0.54 m: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(ii)
Height = 10.8 m: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
State the effect of height on seed dispersal.
[1]
[1]
......................................................................... (c)
Suggest two reasons for the effect of the drop height on the distance travelled by the seeds.
[2]
......................................................................... ......................................................................... ......................................................................... .........................................................................
(This question continues on the following page) 882-135
–3–
N02/410/H(2)
(Question 1 continued) The following graphs show the rate and timing of seed release from different species of grass in the same area during the summer. 100
100
Festuca rubra
Rate of seed fall / number 50 week-1 100 cm-2
Holcus lanatus
Rate of seed fall / number 50 week-1 100 cm-2
0 14 21 28 5 12 19 26 2
June
July
16
August
30 35
June
400
Agrostis stolonifera
600
0 14 21 28 5 12 19 26 2
July
16
30 35
16
30 35
August
Poa trivialis
300
Rate of seed fall / 400 number week-1 100 cm-2 200
Rate of seed fall / number 200 week-1 100 cm-2 100
0 14 21 28 5 12 19 26 2
June
July
16
August
30 35
0 14 21 28 5 12 19 26 2
June
July
August
[Source: J L Harper, Population Biology of Plants , Academic Press (Harcourt Brace Jovanovich) 1997, page 57]
(d)
Identify the grass species which produces the most seeds in this area.
[1]
......................................................................... (e)
Identify the grass species which produces the most seeds in June.
[1]
......................................................................... (f)
Compare seed production for all species relative to the timing of their release.
[3]
......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... (This question continues on the following page) 882-135
Turn over
–4–
N02/410/H(2)
(Question 1 continued) (g)
[2]
Suggest two benefits for these plants in the timing of seed release. ......................................................................... ......................................................................... ......................................................................... .........................................................................
Biological seed dispersal is usually dependent on the nutritional content of the seed or fruit. The following table gives the nutritional content for fruits of different species in temperate and tropical climates. Percentage by Dry Weight Common Name (genus)
Protein
Lipid
Carbohydrate
Dispersal Agents
Temperate Cranberry (Vaccinium) Hawthorn (Crataegus) Pin cherry (Prunus) Pokeberry (Phytolacca) Strawberry (Fragaria)
3 2 8 14 6
6 2 3 2 4
89 73 84 68 88
Birds Birds Birds Birds Birds
16 4 53 4 63
55 79 38 94 9
Birds Bats Birds Monkeys Birds
Tropical Bird palm (Chamaedorea) Fig (Ficus) Mistletoe (Viscum) Monkey fruit (Tetragastris) Wild nutmeg (Virola)
14 7 6 1 2
[Source: H Howe and L Westley, Ecological Relationship of Plants and Animals, Oxford University Press 1988, page 121]
(h)
Compare tropical fruits to temperate fruits in relation to the mean values for lipid, carbohydrate and protein content.
[2]
......................................................................... ......................................................................... ......................................................................... .........................................................................
(This question continues on the following page) 882-135
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(Question 1 continued) (i)
Explain which fruit would have the highest energy content.
[2]
......................................................................... ......................................................................... ......................................................................... ......................................................................... (j)
[2]
Suggest one advantage and one disadvantage of dispersal of seeds by animals. ......................................................................... ......................................................................... ......................................................................... .........................................................................
882-135
Turn over
–6– 2.
N02/410/H(2)
According to cell theory all cells arise from pre-existing cells. The following diagram shows the cell cycle of a eukaryotic (body) cell of a diploid organism.
A
(a)
B
Define the term diploid.
[1]
......................................................................... ......................................................................... (b)
Identify the parts of the cell cycle labelled A and B.
[1]
A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(c)
State three activities that occur during part A of the cell cycle.
[3]
......................................................................... ......................................................................... ......................................................................... ......................................................................... (d)
Outline the differences in cytokinesis in animal and plant cells.
[2]
......................................................................... ......................................................................... ......................................................................... ......................................................................... .........................................................................
(This question continues on the following page)
882-135
–7–
N02/410/H(2)
(Question 2 continued) (e)
Explain the significance of complementary base pairing in relation to the cell cycle.
[3]
......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... .........................................................................
882-135
Turn over
–8– 3.
N02/410/H(2)
The following diagram shows the lac operon which helps to regulate the expression of genes.
Permease ! -galactosidase
DNA
lac I
Promoter
Operator
Acetylase
lac Z lac Y lac A
[Source: Riki Lewis, Human Genetics, 3rd Edition, William C Brown, (1999), page 158]
(a)
Outline the term operon.
[2]
......................................................................... ......................................................................... ......................................................................... ......................................................................... (b)
Outline the relationship between the lac operon and transcription. ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... .........................................................................
882-135
[3]
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N02/410/H(2)
SECTION B Answer two questions. Up to two additional marks are available for the construction of your answers. Write your answers in a continuation answer booklet. Write your name and candidate number on the front cover of the continuation answer booklets, and attach them to this question paper using the tag provided. 4.
5.
6.
7.
(a)
Describe, with the aid of a diagram, the behaviour of chromosomes in the different phases of meiosis.
[5]
(b)
Explain how meiosis and fertilization can give rise to genetic variety.
[6]
(c)
Compare the processes of spermatogenesis and oogenesis.
[7]
(a)
Outline the role of the phloem in the active translocation of biochemicals.
[5]
(b)
Describe the metabolic events of germination in a starchy seed.
[5]
(c)
Explain how abiotic factors affect the rate of transpiration in a terrestrial plant.
[8]
(a)
State one example of an infectious disease caused by a member of each of the following groups: virus, bacteria, fungus and protozoa.
[4]
(b)
Outline the process of immunization.
[6]
(c)
Discuss the benefits and dangers of immunization against bacterial and viral infections.
[8]
(a)
Outline the production of a dipeptide by a condensation reaction. Include the structure of a generalized dipeptide in your answer.
[5]
(b)
Explain the process of translation.
[9]
(c)
List four functions of proteins, giving an example of each.
[4]
882-135
