RVHS 2023 JC2 H2 Prelim P1 QP

RIVER VALLEY HIGH SCHOOL JC2 PRELIMINARY EXAMINATION CANDIDATE NAME CENTRE NUMBER S CLASS 22J INDEX NUMBER BIOLOGY 9744/01 Paper 1 Multiple Choice 22 September 2023 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, Centre number and index number on the Answer Sheet in the spaces provided unless this has been done for you. DO NOT WRITE IN ANY BARCODES. 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. ____________________________________________________________________________ This Question Paper consists of 22 printed pages and 2 blank pages.

2 River Valley High School H2 Biology 9744/01 2023 JC2 Preliminary Examination 1 Which organelle(s) are required in the formation of glycoprotein 120 in the HIV viral envelope? 2 The diagram below shows a lipid molecule E, and a triglyceride. molecule E triglyceride Which row correctly identifies a feature that is present in molecule E and a triglyceride? molecule E triglyceride A one unsaturated fatty acid one saturated fatty acid B no ester bonds three ester bonds C one fatty acid three fatty acids D zero double bonds four double bonds mitochondria Golgi apparatus rough endoplasmic reticulum

3 River Valley High School H2 Biology 9744/01 2023 JC2 Preliminary Examination 3 An experiment was conducted to determine the mode of entry of a water-soluble drug into animal cells. The animal cells were placed into separate containers with different concentrations of the drug. The initial rate of entry of the drug into the cells were measured. The experiment was conducted at two different temperatures, 20 oC and 30 oC. The results are shown in the graph below. Which statement(s) are correct? 1 ATP is not required for the entry of the drug. 2 A change in pH will decrease the rate of drug entry. 3 An increase in membrane fluidity will increase the concentration of the drug inside the cell. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only rate of entry of drug concentration of drug outside cell 20 oC 30 oC

4 River Valley High School H2 Biology 9744/01 2023 JC2 Preliminary Examination 4 Bread contains a protein known as gluten. Some features of the structure of gluten are listed below. 1 Short α- helical sections are present in both polypeptides because of their high proline content. 2 Intermolecular bonds form between different polypeptides. 3 Up to 45% of the amino acids in both polypeptides are glutamine. 4 Hydrophobic amino acids such as glutamine and proline are not found on the surface of gluten proteins. Which row correctly links each of the stated feature to its level of protein structure? primary structure secondary structure tertiary structure quaternary structure A 4 1 3 2 B 1 3 2 4 C 3 1 4 2 D 1 2 4 3 5 The graph shows how the concentration of components 1, 2, 3 and 4, of an enzyme- catalysed reaction changes with time. Which row correctly identifies the components of this reaction? component 1 component 2 component 3 component 4 A enzyme–substrate complex unbound enzyme product substrate B enzyme–substrate complex product substrate unbound enzyme C product enzyme–substrate complex unbound enzyme substrate D product unbound enzyme substrate enzyme–substrate complex 4 concentration time 1 2 3

5 River Valley High School H2 Biology 9744/01 2023 JC2 Preliminary Examination 6 In the production of isoleucine from threonine, the end product acts as an inhibitor of the first enzyme of the pathway. The pathway is shown below. Which of the following graphs shows the changes in concentration of intermediate G when threonine is supplied in excess? A B C D concentration of intermediate G time concentration of intermediate G time concentration of intermediate G time concentration of intermediate G time

6 River Valley High School H2 Biology 9744/01 2023 JC2 Preliminary Examination 7 An experiment was conducted to investigate the effect of temperature on the activity of the enzyme β -glucosidase. The enzyme was tested when in solution (free) and when immobilised in alginate beads. The same amount of enzymes were used. The results are shown in the graph below. Which statements concerning the data in the graph are valid? 1 At all temperatures, immobilisation increased the stability of the enzyme structure. 2 Beyond 30 °C, temperature is now the limiting factor instead of enzyme concentration. 3 Activation energy of immobilised enzymes may be higher than that of free enzymes. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only temperature / oC β-glucosidase activity / arbitrary units immobilised enzyme free enzyme

7 River Valley High School H2 Biology 9744/01 2023 JC2 Preliminary Examination 8 A culture of bacteria was grown in a medium containing 15N. After several generations, all of the DNA contained 15N. The diagram shows the position of the DNA molecules containing 15N in the centrifuge tube. The culture of bacteria was then allowed to reproduce using nucleotides containing the light isotope of nitrogen (14N). DNA samples were taken and separated by centrifugation after the bacteria had divided once and again after the bacteria had divided twice. In which positions would the DNA be found after the bacteria had divided once and after the bacteria had divided twice? after dividing once after dividing twice A half at K and half at L quarter at K quarter at M and half at L B half at K and half at M quarter at K quarter at M and half at L C all at L half at K and half at L D all at M half at L and half at M 9 The structure of nucleic acids facilitates the accurate synthesis of proteins. Which row describing the nucleic acid structure and its role is correct? structure role A A mature mRNA has 997 nucleotides, including a 250-nucleotide poly-A-tail. When translated, the polypeptide has a maximum number of 249 amino acids. B There are 61 different types of tRNA molecules, each with a different anti- codon, present in each cell. During elongation, the activated tRNA brings the correct amino acid to the A- site of the ribosome. C rRNA are single-stranded but can fold to form double-stranded regions via A-T and C-G base-pairing. rRNA has both structural and enzymatic functions in the ribosome. D The hexose sugar in the DNA and RNA nucleotides are deoxyribose and ribose respectively. Both have free 3’-hydroxyl groups that form phosphoester bonds with incoming nucleotides during condensation.

8 River Valley High School H2 Biology 9744/01 2023 JC2 Preliminary Examination 10 The flowchart shows the classification of several types of non-coding eukaryotic DNA. Which statements can be concluded? 1 Q is found at varied positions for all chromosomes in a cell. 2 Q and R are mostly associated with proteins, but S is only associated with proteins during gene expression. 3 S may involve DNA bending but R shortens during DNA replication in all cell types. A 1, 2 and