2026 NJC H2 Bio Prelim P1 (MS)

©NJC 2026 9477/01/SH2 Preliminary Examination [Turn over NATIONAL JUNIOR COLLEGE, SINGAPORE Senior High 2 Preliminary Examination Higher 2 CANDIDATE NAME BIOLOGY CLASS 2bi2_____ REGISTRATION NUMBER Biology Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet 9477/01 16 September 2026 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, Biology class and registration number on all the work you hand in. There are thirty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. Read the instructions on the Answer Sheet very carefully. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. The use of an approved scientific calculator is expected, where appropriate. Your five-digit OAS index number is made up of the second and last four digits of your registration number. For example: Registration no. OAS Index no. 2205123 25123 This document consists of 19 printed pages and 1 blank page.

2 ©NJC 2026 9477/01/SH2 Preliminary Examination 1 The electron micrograph shows some cell structures. Some cell structures are listed. 1 nucleolus 2 chloroplast 3 microtubules 4 ribosomes 5 mitochondria Which cell structures can be seen in the electron micrograph? A 1, 2, 3 and 4 B 1, 4 and 5 C 2, 3 and 5 D 2, 4 and 5

3 ©NJC 2026 9477/01/SH2 Preliminary Examination [Turn over 2 Cell structures can be isolated by centrifuging the cells in a sucrose density gradient. This breaks up the cells and separates the cell structures into fractions. The diagram shows the fractions in a sucrose density gradient after centrifugation. cellular components density chloroplasts and mitochondria 1.18 endoplasmic reticulum 1.16 Golgi bodies 1.06 lysosomes 1.14 ribosomes 1.60 Which fractions contain cell structures that carry out protein synthesis? A 1, 2 and 3 B 2, 3 and 4 C 2, 3 and 5 D 3, 4 and 5 3 The diagrams show three types of covalent bonds. Which bonds will be found in glycolipids and glycoproteins? bond 1 bond 2 bond 3 A glycolipids only glycolipids and glycoproteins glycoproteins only B glycolipids and glycoproteins glycolipids only glycoproteins only C glycoproteins only glycolipids only glycolipids and glycoproteins D glycoproteins only glycolipids and glycoproteins glycolipids only

4 ©NJC 2026 9477/01/SH2 Preliminary Examination 4 The table shows the results of an experiment on the rate of uptake of sugars by rat intestine. sugars rate of absorption under aerobic conditions under anaerobic conditions hexose sugars glucose 100 30 galactose 106 32 pentose sugars xylose 32 32 arabinose 30 30 Which conclusion may be drawn from the results? A All four sugars can be absorbed by active transport. B Only hexose sugars can be metabolised by the rat. C The intestine is freely permeable to hexose sugars. D The rate of passive diffusion of all four sugars into the gut is similar.

5 ©NJC 2026 9477/01/SH2 Preliminary Examination [Turn over 5 Some students investigated the effect of pH on the rate of starch digestion by amylase. • They added 2 cm3 of a 1% amylase solution and 1 cm3 of pH 4 buffer to a test-tube. • They added 2 cm3 of a starch solution, containing 0.02 g of starch, to the test-tube. • They measured the time taken for the starch to be digested (to disappear). The students then repeated these steps with pH 5, pH 6, pH 7 and pH 8 buffers. The table shows the results. pH time taken for starch to be digested/ minutes 4 5 6 7 8 4.0 1.5 1.0 2.5 6.0 Which graph is correct for these data?

6 ©NJC 2026 9477/01/SH2 Preliminary Examination 6 Scientists cultured two populations of human stem cells for many generations. • Population P consisted of adult stem cells. • Population Q consisted of embryonic stem cells. Which prediction about telomere length is most likely? population P population Q A telomeres are completely lost telomeres lengthen continuously B telomeres lengthen continuously telomere length is unchanged C telomere length is largely maintained telomeres shorten gradually D telomeres shorten gradually telomere length is largely maintained 7 The nucleic acids present in a cell of the bacterium Escherichia coli were analysed. Some of the results are shown in the table. type of nucleic acid number of different variants number of molecules per cell percentage of dry mass of cell 1 600 2500 2 2 60 160 000 3 3 2 20 000 21 Which row identifies each type of nucleic acid, 1, 2 and 3? 1 2 3 A DNA mRNA tRNA B mRNA tRNA rRNA C rRNA DNA mRNA D tRNA rRNA DNA

7 ©NJC 2026 9477/01/SH2 Preliminary Examination [Turn over 8 Which row describes the role of the enzymes DNA polymerase and DNA ligase? DNA polymerase DNA ligase A adds nucleotides in a 5’ to 3’ direction joins sections of DNA together on the lagging strand B adds nucleotides in a 3’ to 5’ direction joins sections of DNA together on the leading strand C adds nucleotides in a 5’ to 3’ direction joins sections of DNA together on the leading strand D adds nucleotides in a 3’ to 5’ direction joins sections of DNA together on the lagging strand 9 One hypothesis about the origin of viruses is that they existed before cellular life forms, later evolving into parasites of cellular organisms. Groups with an ancient, common origin tend to share conserved sequences of DNA or RNA. Which observation about virus genomes supports the view that viruses existed before cellular life forms and only much later evolved into parasites? A All viruses have genes that code for capsid components. B Introns of eukaryotic genes have common features with viral genomes. C Large virus genomes have genes that originate in host cells. D Viral genomes have conserved genes not found in any other genomes. 10 In an experiment using bacteriophage, different component molecules were labelled. • Protein coats were labelled with radioactive sulfur. • DNA was labelled with radioactive phosphorus. The labelled bacteriophages were allowed to infect host bacteria. The inside and outside of infected bacteria before lysis were tested for radioactive sulfur and radioactive phosphorus. Which set of results would be expected? radioactive molecules inside bacterial cells outside bacterial cells A phosphorus sulfur B phosphorus and sulfur phosphorus C sulfur phosphorus D sulfur phosphorus and sulfur

8 ©NJC 2026 9477/01/SH2 Preliminary Examination 11 The electron-micrographs below show two different processes of genetic transfer in bacteria. The statements concerning genetic transfer in bacteria are shown below. 1 Specific gene from the donor bacterium is transferred. 2 Only bacteria with a specific plasmid can act as donors. 3 Physical contact between the donor and recipient bacterium is necessary. 4 The donor bacterium is lysed during the process. Which row shows the correct statements for processes R and S? process R process S A 1 and 2 3 and 4 B 1 and 4 2 and 3 C 2 and 3 1 and 4 D 3 and 4 1 and 2

9 ©NJC 2026 9477/01/SH2 Preliminary Examination [Turn over 12 The following are characteristics of eukaryote transcription. • A promoter may contain recognition sites for several transcription factors. • Some transcription factors can recognise similar DNA sequences. • More than one transcription factor may be able to bind to the same recognition site. • Binding of different transcription factors can have different effects on transcription. What