2024 RI H2 Bio P3 MS

© RI 2024 Preliminary Examination 9744/03 [Turn over RAFFLES INSTITUTION 2024 Year 6 Preliminary Examination Higher 2 BIOLOGY 9744/03 Paper 3 Long Structured and Free-response Questions 11 Sept 2024 2 hours Candidates answer on the Question Paper. Additional Materials: Writing paper. R E A D T H E S E I N S T R U C T I O N S F I R S T Write your index number, CT group & name in the spaces at the top of this page. Write in dark blue or black pen. You may use a HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Section A Answer all questions in the spaces provided on the Question Paper. Section B Answer any one question in the writing paper provided. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. At the end of the examination, hand in your essay question SEPARATELY. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 19 printed pages. CIVICS GROUP CANDIDATE NAME INDEX NUMBER 4 S 0 3 2 Raffles Institution Internal Examination For Examiner’s Use Section A 1 / 30 2 / 11 3 / 9 Section B 4 or 5 / 25 Total / 75

2 © RI 2024 Preliminary Examination 9744/0 3 For Examiner’s Use Section A Answer all the questions in this section. 1 The human papillomavirus (HPV) is sexually transmitted and can cause the development of cervical intraepithelial neoplasia (CIN). Patients with CIN are o b s e r v e d t o h a v e a b n o r m a l growth of cells that line the cervix. This can lead to the development of cervical cancer. Fig. 1.1 shows the structure of the HPV. Fig. 1.1 (a) With reference to Fig. 1.1, compare the structure of HPV with a T4 bacteriophage. .……………………………………………………...…………………………………………………… .……………………………………………………...…………………………………………………… ………………………………………………………...…………………………………………………. …………………………………………………………...………………………………………………. .………………………………………………………..………………………………………………… ………………………………………………………..………………………………………………[3] Similarities 1. The genome of both viruses are enclosed by a protein capsid*; OR Both viruses have a capsid* which is made up of several individual protein subunits (capsomeres); 2. Both viral genomes are made up of DNA*; Differences capsid protein L1 histone capsid protein L2 genomic DNA

3 © RI 2024 Preliminary Examination 9744/0 3 [Turn over For Examiner’s Use 3. The HPV has DNA associated with histone protein, while the T4 bacteriophage DNA does not associate with histone protein; 4. spherical capsid vs icosahedral capsid head 5. T4 bacteriophage has a sheath, collar, tail and tail fibres (name any 1) while the HPV has does not; (A only if no mark point 4 or 5: The HPV has a spherical shape, while the T4 bacteriophage has a complex shape) 6. The HPV has 2 types of capsid proteins, L1 and L2, while the T4 bacteriophage has only 1 type. A recent study assessed the impact of routine vaccination against HPV on the development of CIN. Fig. 1.2 shows the effect of HPVvaccination on the percentage of women found to have the most severe grade of CIN by cervical screening over the years. Fig. 1.2 (b) With reference to Fig. 1.2, explain how the data support the suggestion that vaccination against HPV could lead to herd immunity. .……………………………………………………...…………………………………………………… .……………………………………………………...…………………………………………………… ………………………………………………………...…………………………………………………. …………………………………………………………...………………………………………………. .………………………………………………………..………………………………………………… ………………………………………………………..………………………………………………[3] 1. Vaccination programme started in 1990 and resulted in lower (A: low) % of women with CIN amongst the vaccinated women, preventing transmission of HPV; 2. Due to % of vaccinated women reaching sufficiently high numbers/ number reaching critical threshold from 1992; 3. Resulting in a decrease in the percentage of non-vaccinated women with the most severe CIN from 0.7% to 0.2% from 1992 (R: 1990) to 1996 (A: 1995).

4 © RI 2024 Preliminary Examination 9744/0 3 For Examiner’s Use (c) Fig. 1.3 shows the number of cases of cervical cancer and death rate from cervical cancer in females of different ages in one year. Fig. 1.3 With reference to Fig. 1.3, ( i ) describe changes that occur in the number of cases of cervical cancer from the ages of 20–29 to 90–99. ………………………………………………………………………………….………………… ………………………………………………………………………………….………………… ………………………………………………………………………………….………………… ………………………………………………………………………………………..………..[2] 1. As age increases from 20-29 to 30-39 the number of cases of cervical cancer increases from 24 to 38 per 100 000/increases by 14 per 100 000; 2. and then from ages 30-39 to 90-99, the number of cases of ce rvical cancer decreases from 38 to 8 per 100 000/decreases by 30 per 100 000; (must quote values with units for both axes correctly to award marks)

5 © RI 2024 Preliminary Examination 9744/0 3 [Turn over For Examiner’s Use ( i i ) Suggest a reason for the decrease in the death rate from cervical cancer between ages 80–89 and 90–99. …………………………………………………………………………………………………… …………………………………………………………………………………………………[1] Many females with cervical cancer have died before this age; OR Many females with cervical cancer died of other causes; ( i i i ) Express as a simplest whole number ratio, the number of cases compared to death rate at ages 30–39. [1] 38:4 =19:2 ______________: ________ number of cases : death rate ( i v ) The human papillomavirus (HPV) is commonly associated with cases of cervical cancer. Many countries have a vaccination programme against HPV. Use information from Fig. 1.3 to suggest why females are given the vaccine in their teenage years. …………………………………………………………………………………………………[2] 1. There are no cases below 20/in teenage years/between 0-19/10-19 OR From (age) 20-29/after teenage/in adult years there are cases (of cervical cancer); 2. Thus girls are given the vaccine before they are likely to be sexually active/ infected by the HPV; ( v ) The HPV vaccination programme is being extended to boys’ schools. Explain the advantages of: offering the HPV vaccine to boys, …………………………………………………………………………………………………[2] Advantages of vaccinating boys 1. protects boys from becoming infected so the virus is less likely to get passed on to girls during intercourse; 2. greater chance of developing herd immunity ; 3. help to protect girls who cannot be vaccinated; 4. protects boys from becoming infected and developing other types of HPV-related cancer; and carrying out the vaccination programme in schools. …………………………………………………………………………………………………[1] Advantages of vaccination in schools

6 © RI 2024 Preliminary Examination 9744/0 3 For Examiner’s Use 5. more boys / girls likely to be vaccinated because they are not reliant on a doctor's appointment being made / available; 6. seeing others being vaccinated might encourage others to get vaccinated; 7. inoculating school children is likely to be before they become sexually active so less likely to get infected;