# Life Sciences Grade 12 Paper 2 KZN Prelim 2024 Memo > Grade 12 Life Sciences Paper 2 memorandum from the KZN Prelim Exam 2024, 27 pages. Read online or download the free PDF. - Page: https://www.hlayiso.com/library/kzn-life-sciences-grade-12-september-2024-p2-and-memo/9349dac5-ff79-4eeb-982f-6883ffa34d12 - Updated: 2026-09-27 - Subject: Life Sciences - Grade: Grade 12 - Document type: Memorandum - Year: 2024 - Exam period: KZN Prelim Exam - Paper: 2 - Curriculum: CAPS - Pages: 27 Breadcrumbs: [Home](https://www.hlayiso.com/) › [Library](https://www.hlayiso.com/library) › [Grade 12](https://www.hlayiso.com/library/grade-12) › [Life Sciences](https://www.hlayiso.com/library/grade-12/life-sciences) › [Life Sciences Grade 12 Paper 2 KZN Prelim 2024 Memo](https://www.hlayiso.com/library/kzn-life-sciences-grade-12-september-2024-p2-and-memo/9349dac5-ff79-4eeb-982f-6883ffa34d12) ## About this document Life Sciences · Grade 12 · KZN Prelim Exam · 2024. Memorandum, 27 pages. Read online or download the PDF. Read it free online on the page above; download the PDF from there. ## Document text Text extracted from the PDF. Layout, diagrams and tables may not survive extraction. ### Page 1 Downloaded from hlayiso.com Downloaded from Stanmorephysics.com KWAZULU-NATAL PROVINCE EDUCATION REPUBLIC OF SOUTH AFRICA NATIONAL SENIOR CERTIFICATE GRADE 12 MARKS: 150 TIME: 2% hours N.B. This question paper consists of 16 pages. Copyright Reserved Please Turn Over ### Page 2 Life Sci Downloaded from hlayiso.com vA : Si 2024 Pr Examinati jowhloaded from Stanmorepkysics.comi °°" *0% Peramioy Bamnaton INSTRUCTIONS AND INFORMATION Read the following instructions carefully before answering the questions. 10. 11. Answer ALL the questions. Write ALL the answers in the ANSWER BOOK. Start the answers to each question at the top of a NEW page. Number the answers correctly according to the numbering system used in this question paper. Present your answers according to the instructions of each question. Do ALL drawings in pencil and label them in blue or black ink. Draw diagrams, tables or flow charts only when asked to do so. The diagrams in this question paper are NOT necessarily drawn to scale. Do NOT use graph paper. You may use a non-programmable calculator, protractor and a compass. Write neatly and legibly. Copyright Reserved Please Turn Over ### Page 3 Downloaded from hlayiso.com Life SCS WA loa de d from Ss tanmorephysics.conv™"*™ Preparatory Examination SECTION A QUESTION 1 1.1. Various options are provided as possible answers to the following questions. Choose the answer and write only the letter (A to D) next to the question number (1.1.1 to 1.1.9) in the ANSWER BOOK, for example 1.1.10.D. 1.1.1. Which ONE of the following occurs in mitosis but NOT in meiosis? Crossing over takes place Two cells are formed at the end of the division Homologous chromosomes arrange at the equator Centrioles form at the poles of the cell 0QOWD> 1.1.2 The scientists who discovered that DNA is double helix. Crick and Watson Franklin and Wilkins Watson and Wilkins Wilkins and Crick 00ODND> 1.1.3. Which ONE of the following is an ac Lamarck's theory of evolution? _» eptable explanation based on A __ An increasi at are resistant to insecticides because they id reproduce B__ Giraffes have lo ect d e have short necks C Humans evolve 2 D- The ete ngers removed will give birth to children withou P 5 1.1.4 Which ONE of the following is an acceptable explanation based on Mendel’s law of segregation? A Various ‘factors' controlling the different characteristics separate out independently during gamete formation B Two ‘factors' separate so that each gamete contains different ‘factors’ C Heterozygous individual for a particular characteristic will have the dominant trait as the phenotype D_ Two ‘factors' separate so that each gamete contains only one of these ‘factors’ Copyright Reserved Please Turn Over ### Page 4 Downloaded from hlayiso.com Life Sci Si P2 September 2024 Preparatory Examination whloaded from Stanmorephysics.com 1.1.5-..DNA was extracted from the cells of a cat and was analysed for its nitrogenous base composition. It was found that 26% of the bases are guanine. What percentage of the bases are thymine? A 26 B 52 Cc 24 D 48 1.1.6 A female that has received two identical alleles for haemophilia from each parent is described as being ... A dominant B homozygous C homologous D heterozygous 1.1.7. The diagrams below represent the four phases of meiosis in no sequence. ACU) K XZ Which ONE of the following is the correct sequence in which the phases of meiosis occur? PPAw Oane NNBPN =W0-— 0C0NOWDDY Copyright Reserved Please Turn Over ### Page 5 Life Sciggces P2 fo) Downloaded from hlayiso.com September 2024 Preparatory Examination Whloaded from Stanmorepkysics.coni 1.1.8--A mother has blood type O and father blood type AB. They have two biological children and two adopted. The genotypes of all children are represented in the table below. CHILDREN GENOTYPE Peter a Paul ii Penny 18) Patricia Ae Children adopted are ... won P -2 1.1.9 The diagram below shows the process fertilisation in humans. Peter and Paul Paul and Penny Penny and Patricia Patricia and Paul Gamete A Gamete B Which ONE of the following correctly represents the chromosomes in gamete A and B respectively? 0 QO BD PY Copyright Reserved GAMETE A GAMETE B 23 autosomes and Y 21 autosomes and X gonosome gonosome 22 autosomes and Y 22 autosomes and X gonosome gonosome 22 autosomes and X 22 autosomes and X gonosome gonosome 22 autosomes and X 23 autosomes and X gonosome gonosome (9 x 2) (18) Please Turn Over ### Page 6 Life Sciggces P2 fo) wn Downloaded from hlayiso.com loaded from Stanmorephysics.com 1.2 Give the correct biological term for each of the following descriptions. Write only the term next to the question number (1.2.1 to 1.2.9) in the ANSWER BOOK. 1.2.1. A disorder due to the presence of an extra chromosome on the chromosome pair 21 in somatic cells of humans 1.2.2 Similar structures that are inherited from a common ancestor and modified for different function 1.2.3. Asegment of a chromosome that codes for a particular characteristic 1.2.4 The stage in protein synthesis during which mRNA is coded from DNA 1.2.5 Undifferentiated cells that have the potential to form any body tissue 1.2.6 The study of the distribution of living organisms found in different regions 1.2.7 The type of nucleic acid that carries a specific amino acid 1.2.8 The chromosome condition describing the presence of a single set of chromosomes in a cell 1.2.9 An allele that is expressed phenotypically only in the homozygous condition (9x 1) 1.3. Indicate whether each of the descriptions in COLUMN | applies to A ONLY, B ONLY, BOTH A AND B or NONE of the items in COLUMN II. Write A only, B only, both A and B, or none next to the question number (1.3.1 to 1.3.2) in the ANSWER BOOK. COLUMN | COLUMN II 1.3.1. | The random arrangement of A: Metaphase | chromosomes at the equator singly B: Metaphase II 1.3.2 | The natural shape of the DNA molecule A: Double helix B: Single helix 1.3.3. | The site of meiosis in plants A: Stigma B:_ Anther Copyright Reserved (3 x 2) September 2024 Preparatory Examination (9) (6) Please Turn Over ### Page 7 Life Sciggces P2 fe] wn Downloaded from hlayiso.com loaded from Stanmorepbysics.com 1.4 The diagram below shows a process during meiosis. The letters represent the alleles of genes in the chromosomes. 1.4.1 1.4.2 1.4.3 1.4.4 1.4.5 Copyright Reserved Name the: (a) Process shown in the diagram (b) Phase of meiosis represented above Identify: (a) PointD (b) PartB Write down the LETTER and NAME of the part that join together two chromatids. Write down the genotype of the resulting chromatid A after the process named in QUESTION 1.4.1 (a). State how many: (a) Characteristics are represented in the diagram above. (b) Different genes are represented by the alleles in the diagram above. September 2024 Preparatory Examination (1) (1) (1) (1) (2) (1) (1) (1) (9) Please Turn Over ### Page 8 Downloaded from hlayiso.com “<“Bowhloaded from Stanmorephysics.com 1.5 Fossils are used as the evidence for human evolution. The table below shows the period of existence of some hominids. HOMINID PERIOD OF EXISTENCE Australopithecus aferensis 4-3 mya Australopithe: ricanus 3.2-2 mya 2.2-—1.4 mya 2-0.4 mya 0.4 - 0.05 mya 0.2—0 mya 1.5.1 With refere’ f above, name TWO: (a) Genera (b) Species that existed for the longest period of time. 1.5.2 State how long did Homo habilis live on earth. 1.5.3 Name: (a) TWO fossils of Australopithecus africanus that were discovered in Sterkfontein. (b) The family to which Homo sapiens belong. TOTAL SECTION A: September 2024 Preparatory Examination (2) (2) (1) (2) (1) (8) 50 Copyright Reserved Please Turn Over ### Page 9 Downloaded from hlayiso.com Life Sciggces P2 September 2024 Preparatory Examination Gwhloaded from Stanmorepkysics.com SECTION B QUESTION 2 2.1. Pepsin (protein digesting enzyme) is a protein secreted in the stomach as an inactive pepsinogen. The TABLE 1 below shows the sequence of bases on the mRNA coding for some of the amino acids in a pepsin protein. 1 2 3 4 5 6 if UUC | AAG | CUG | UGG | GAU | AUC | UGG 2.1.1. Give the number of: (a) Different anticodons needed to form this part of a pepsin protein. (1) (b) Phosphates on the mRNA base triplets in the table above. (1) 2.1.2 Name the organelle where pepsin is synthesised in a human cell. (1) 2.1.3. The TABLE 2 below shows the amino acids and DNA base triplets. DNA BASE AMIND, ed TRIPLET ci [tac With reference to the TABLE 1 in QUESTION 2.1 and TABLE 2 above: (a) | Give the correct sequence of the tRNA base triplet that brings tyrosine for the synthesis of pepsin. (1) (b) | Give the amino acid coded for by the mRNA base triplet number 3. (1) (c) A mutation caused the mRNA base triplet number 6 to change from UUC to AUC. Explain the effect of this mutation on the protein formed. (4) (d) | Describe the type of mutation referred to in QUESTION 2.1.3 (c). (2) (11) Copyright Reserved Please Turn Over ### Page 10 Downloaded from hlayiso.com Life Sci Si P2 September 2024 Preparatory Examination Weer Whloaded from Stanmorepkysics.comi 2.2 Read the information below. DNA profiling is a forensic technique in criminal investigations. It is a tool for determining the identity of a specific DNA sample to solve legal disputes and notably help to determine paternity. Faulty preparation procedures during DNA profiling may cause problems. Other errors that may occur during DNA profiling include contamination of samples, intentional planting of DNA samples, and mistakes during interpretation of results. All this may lead to discrepancies in legal proof in court cases. 2.2.1. From the information above, state ONE: (a) Use of DNA profiling other than determining paternity. (1) (b) Effect of faulty preparations during DNA profiling. (1) 2.2.2 Explain how the DNA profiling is used in paternity testing. (6) (8) 2.3 In cattle, long horns (L) and a twisted horns (T) are dominant over short horns and straight horns. The diagram below shows part of a genetic cross between a bull and cow. A cow is heterozygous for the length of horns. P1 Bull Xx Cow (Long and straight horn) Genotype i Xx A Phenotype 6 long and twisted horns _ 6 long and straight horns offspring 2 short and twisted horns 2 short and straight horns 2.3.1 Name the type of dominance displayed by the horn length and shape. (1) 2.3.2 Give: (a) The phenotype of a bull. (1) (b) ALL the possible genotypes in the gametes of a bull. (3) (c) The genotype at A above. (1) (d) The phenotypic ratio for short and straight horns to long and twisted horns offspring. (1) (7) Copyright Reserved Please Turn Over ### Page 11 Life Sciggces P2 fe] 2.4 The diagram below shows the inheritance of fur colour in rabbits. Downloaded from hlayiso.com whloaded from Stanmorepkysics.co September 2024 Preparatory Examination m O- Og | © @ | Brown fur * Brown fur OC) wnite fur White fur 2.4.1 Name the phenotype that is controlled by the recessive allele. 2.4.2 Explain your answer in QUESTION 2.4.1. 24.3 2.4.4 Give a reason for your answer in QUESTION 2.4.3. (1) (4) Identify the parents that support the conclusion that both rabbits with brown and white fur coat belong to the same species. (1) (2) 2.4.5 State how many generations in the diagram have heterozygous rabbits? (1) 2.4.6 Rabbit 11 was crossed with a white fur coat colour rabbit. Copyright Reserved Using the letters B and b, do a genetic cross to show the phenotypic ratio of their offspring. (7) (16) Please Turn Over ### Page 12 Downloaded from hlayiso.com Life Sci Siwh loa de d from Stanmore B sics.com nr Preparatory Examination 2.5 Read the passage below. Farmers can kill weeds by spraying glyphosate which targets EPSPS (enzyme) which is essential for plant life. Weeds are consistently developing resistance to herbicides. Soybean was genetically modified using glyphosate-resistant gene from the cell_of a resistant weed. Genetically modified organism (GMO) such as soybean has an impact on food security and resistance to diseases. The environmental impact of genetically modified soybeans includes the increased herbicide usage which pollutes air. The consumption of GMO foods can cause allergic reactions and increased antibiotic resistance. 2.5.1. Define the term genetically modified organism. (2) 2.5.2 From the passage, give TWO: (a) Negative effects of GMO in human health (2) (b) Benefits of GMO in agriculture (2) 2.5.3 Explain why the gene of a weed cell was used in modifying soybean. (2) (8) [50] Copyright Reserved Please Turn Over ### Page 13 Downloaded from hlayiso.com Life Sciggces P2 September 2024 Preparatory Examination Gwhloaded from Stanmorepkysics.com QUESTION 3 3.1. Read the information below. Colour blindness (b) occurs when there is a problem with the pigments in certain nerve cells of the photoreceptors in the retina. Parents pass down the red-green colour vision deficiency to the offspring. The diagram below represents the human somatic cell. 484.28 83 aK x3 “AR GH BH BS BS 4B 13 14 15 16 17 18 = 7 XR KR AA AA 09 19 20 21 22 23 3.1.1 Identify the diagram above. (1) 3.1.2 Name the type of photoreceptors referred to in the information above. (1) 3.1.3 Give the: (a) Collective name for the type of chromosomes in pair numbered 23 (1) (b) Genotype of the male who is colour blind. (1) 3.1.4 State THREE characteristics of the autosomal homologous chromosome pairs. (3) 3.1.5 Give ONE reason why this diagram represents the human somatic cell. (1) (8) Copyright Reserved Please Turn Over ### Page 14 Downloaded from hlayiso.com Life Sci Siwh loa de d from Ss tanmore Ki sics.com nr Preparatory Examination 3.2 There are insects called Fireflies, their blood contain a toxic chemical called lucibufagin. They produce a glowing light to warn predators that they are toxic. A scientist conducted an investigation to determine the relationship between the toxic chemical and survival of the insects against predation. Fireflies and non-toxic fruit flies were collected (200 each). Both insects were released into the greenhouse structure in a controlled environment. e The lizards of the same species that are feeding on insects were released into the greenhouse structure for one day. e The number of survived insects was counted and recorded 3 times a day. The percentage of insects survived are shown in the graph below. 100 90 80 70 60 50 = 40 - — 30 4— “all @Fruit flies el OFireflies 20 7— 10 12 14 Time (Hours) Percentage of insects survived 3.2.1. State the aim of the investigation. (2) 3.2.2 Identify the dependent variable of the investigation. (1) 3.2.3 State THREE planning steps to consider when conducting this investigation. (3) 3.2.4 State ONE way in which the scientist ensured the: (a) Validity of the results (1) (b) Reliability of the results (1) 3.2.5 Calculate the number of fruit flies that have survived from predation in 10 hours. Show ALL workings. (3) (11) Copyright Reserved Please Turn Over ### Page 15 Downloaded from hlayiso.com Life Sci Si P2 September 2024 Preparatory Examination Whloaded from Stanmorepkysics.comi 3.3. Describe the process of speciation through geographic isolation. (6) 3.4 Different insecticides were used to control weeds in fields. The insecticides kill insects, Random mutations within the insects over time, has caused the insects to be resistant to insecticides. Colorado potato beetle has a remarkable ability to develop resistance to a wide range of insecticides. Colorado potato beetle has shown a continuous resistance to different insecticides since 1960. The table below shows the number of different insecticides that were resisted by the Colorado potato beetle over years. Year Number of insecticides that were resisted 1960 2 1970 10 1980 28 1990 38 2000 40 2010 40 3.4.1. State ONE way in which the resistance of Colorado potato beetle was determined in the investigation over years. (1) 3.4.2 Describe the change in insecticide resistance over time. (3) 3.4.3. Explain the economic impact caused by the Colorado potato beetle resistance to insecticides. (3) 3.4.4 Use Darwin's theory of natural selection to explain the evolution of insecticide-resistant Colorado potato beetle. (6) [13] Copyright Reserved Please Turn Over ### Page 16 Life Sciggces P2 fe] 3.5 The dia Downloaded from hlayiso.com grams below show the pelvises of the African ape and modern human. The diagrams are not drawn to scale. 3.5.1 3.5.2 3.5.3 3.5.4 Copyright Reserved Identify a diagram of the pelvis above that belongs to an African ape? Tabulate TWO visible differences between pelvis in diagrams A and B. Explain the significance of the position of the foramen magnum that is associated with the pelvis in diagram B. The ‘Out of Africa’ hypothesis is one explanation of the evolution of modern humans. Describe how genetic evidence is used to support the ‘Out of Africa’ hypothesis. TOTAL SECTION B: GRAND TOTAL: September 2024 Preparatory Examination Whloaded from Stanmorepkysics.comi (1) (2) (4) (12) [50] 100 150 ### Page 17 Downloaded from hlayiso.com Downloaded from Stanmorephysics.com KWAZULU-NATAL PROVINCE EDUCATION REPUBLIC OF SOUTH AFRICA NATIONAL SENIOR CERTIFICATE GRADE 12 ~ =i § , gamorephwies.com MARKS: 150 This marking guideline consists of 11 pages. Please Turn Over ### Page 18 Life Sci Downloaded from hlayiso.com ices P2 September 2024 Preparatory Examination Gwhloaded from Stanmoraphysics&scom PRINCIPLES.RELATED TO MARKING LIFE SCIENCES SEPTEMBER 2024 10. 11. 12. If more information than marks allocated is given Stop marking when maximum marks are reached and put a wavy line and ‘max’ in the right-hand margin. If, for example, three reasons are required and five are given Mark the first three irrespective of whether all or some are correct/incorrect. If whole process is given when only part of it is required Read all and credit relevant part. If comparisons are asked for and descriptions are given Accept if differences / similarities are clear. If tabulation is required but paragraphs are given Candidates will lose marks for not tabulating. If diagrams are given with annotations when descriptions are required Candidates will lose marks If flow charts are given instead of descriptions Candidates will lose marks. If sequence is muddled and links do not make sense Where sequence and links are correct, credit. Where sequence and links is incorrect, do not credit. If sequence and links becomes correct again, resume credit. Non-recognised abbreviations Accept if first defined in answer. If not defined, do not credit the unrecognized abbreviation but credit the rest of answer if correct. Wrong numbering If answer fits into the correct sequence of questions but the wrong number is given, it is acceptable. If language used changes the intended meaning Do not accept. Spelling errors If recognizable accept provided it does not mean something else in Life Sciences or if it is out of context. Copyright Reserved Please Turn Over ### Page 19 Life Sci 13. 14. 15. 16. 17. 18. Downloaded from hlayiso.com ices P2 September 2024 Preparatory Examination Gwhloaded from Stanmoraphysies&scom If common names given in terminology Accept provided it was accepted at the National memo discussion meeting. If only letter is asked for and only name is given (and vice versa) No credit If units are not given in measurements Candidates will lose marks. Memorandum will allocate marks for units separately Be sensitive to the sense of an answer, which may be stated in a different way. Caption All illustrations (diagrams, graphs, tables, etc.) must have a caption Code-switching of official languages (terms and concepts) A single word or two that appears in any official language other than the learners’ assessment language used to the greatest extent in his/her answers should be credited, if it is correct. A marker that is proficient in the relevant official language should be consulted. This is applicable to all official languages. Copyright Reserved Please Turn Over ### Page 20 Downloaded from hlayiso.com Life Sci s P2 September 2024 Preparatory Examination Whloaded from Stantworaphysicséncom SECTION A QUESTION 1 1.1 fie AyByvY 1.7.2- Avv 1-1-3- 9D 11.9 Cvv (9x2) (18) 1.2 1.2.1 Down Syndrome ¥ 1.2.2 Homologous structure Vv 1.2.3 Genev 1.2.4 Transcription Vv 1.2.5 Stem cells v 1.2.6 Biogeography Vv 1.2.7 tRNAY 1.2.8 Haploid v 1.2.9 Recessive Vv (9x1) (9) 1.3. 1.3.1 Bonlyvv 1.3.2 Aonlyvv 1.3.3 Bonly vv (3x2) (6) Copyright Reserved Please Turn Over ### Page 21 Life Sciggces P2 Gwhloaded from Stanmoraphysics&com 14 1.44 1.4.2 1.4.3 1.4.4 1.4.5 1.5 1.5.1 1.5.2 1.5.3 Copyright Reserved Downloaded from hlayiso.com (a) Crossing over v (b) Prophase | ¥ (a) Chiasma v (b) Chromosome ¥ CY Centromere v rTnD V (any order) (a) 4v (b) 4v (a) - Australopithecus “ - Homo ¥ (b) - Australopithecus africanus - Homo erectus ¥ 0.8 million years V / 800 thousand years (a) - Mrs Ples v - Little Foot v (b) Hominidae v September 2024 Preparatory Examination (2) (2) (1) (2) (1) (8) TOTAL SECTION A: 50 Please Turn Over ### Page 22 Downloaded from hlayiso.com Life Sciggces P2 September 2024 Preparatory Examination Gwhloaded from Stanmoraphysics&scom SECTION B QUESTION 2 21 244 (a) 6v (1) (b) 21” (1) 2.1.2. Ribosome ¥ (1) 2.1.3. (a) AUGY (1) (b) Leucine ¥ (1) (c) iffe in willbe formed v leucine Y in a protein Any (4) (d) -C e of bases v / nucleotides -a gene mutation will occurY Any (2) (11) 2.2 2.2.1 (a) Determining identity of criminals ¥ (1) (Mark the first ONE only) (b) Discrepancies in legal proof in court cases v (1) (Mark the first ONE only) 2.2.2 -Achild received DNA from both parents v - DNA profiles of the mother, child and the possible father are determined v - DNA bars of the mother and the child are compared v - Remaining DNA bars are compared to the possible father's DNA barsv - If all the remaining DNA bars in the child’s profile match the possible father’s DNA bars¥ - then the possible father is the biological fatherv - If all the remaining DNA bars in the child’s profile does not match the possible father DNA barsv - then the possible father is not the biological fathery’ Any (6) (8) Copyright Reserved Please Turn Over ### Page 23 Life Sciggces P2 wn 2.3 2.3-4 2.3.2 24 2.4.1 2.4.2 2.4.3 2.4.4 24.5 2.4.6 Downloaded from hlayiso.com loaded from Stanmoraphysics&com Complete dominanceY (a) Long and twisted hornsv (b) -LT -Ulyyy -IT -It (c) Littv (da) 1:3¥ White fury” - Both individual 3 and 4 have brown fur” - The offspring 7 has white furw” - which is expressed in the phenotype of homozygous condition’ - Each parent must be heterozygousv /carrying recessive allele - The offspring inherited recessive allele from both parentsY 5 and 6 v - They interbreed v - and produce a fertile offspring v 4v P, Phenotype Brown fur x White fury” Genotype Bb x bby Meiosis Gametes Fertilisation Fy Genotype Phenotype Phenotypic ratio: Pi and Fiv September 2024 Preparatory Examination (1) (1) (3) (1) (1) (7) (1) (4) (1) (2) (1) Meiosis and fertilisation’ Compulsory mark 1* + Any 6 OR Copyright Reserved Please Turn Over ### Page 24 Downloaded from hlayiso.com Life Sciences P2 September 2024 Preparatory Examination Whloaded from Stanworaphysicécom P, Phenotype Brown fur x white fury’ Genotype Bb. x bbv Meiosis . Fertilisation Fy Phenotype 2 brown fura Phenotypic ratio: 1:1v* Pi and Fiv Meiosis and fertilisation’ Compulsory mark 1* + Any 6 (7) (16) 2.5 2.5.1. Anorganism in which the genetic material is manipulated for the benefit of a human desirable characteristicv Vv (2) 2.5.2 (a) - Allergic reactionsY - Antibiotic resistancev (2) (Mark the first TWO only) (b) - Food security” - Resistance to diseasesY (2) (Mark the first TWO only) 2.5.3. - To produce a glyphosate-resistant soybeanv - since weeds are resistant to glyphosateY (2) (8) [50] Copyright Reserved Please Turn Over ### Page 25 Downloaded from hlayiso.com Life Sci Si P2 September 2024 Preparatory Examination Whloaded from Stanworaphysiasécom QUESTION 3 3.1 3.4.1-— KaryotypeY (1) 3.1.2 - Conesv¥ (1) 3:1.3.. (a) Gonosomesv/sex chromosomes (1) (b) xeyv (1) 3.1.4 - Similar sizev - Similar shapev - Same location of centromereY - Position of genev’/ alleles - Genes coding for the same characteristicsY Any (3) 3.1.5 - 46 chromosomesv / 23 pairs of chromosome (1) (8) 3.2 3.2.1. To determine the relationship between the toxic chemicals and survival of insects Vv (2) 3.2.2 Survival of insects” (1) 3.2.3. - Obtain permission from the greenhouse owner to conduct investigation’ - Decide on the sample sizev - Decide on the recording toolY - Decide on time/datev - Decide on the insect types” - Decide on the predator typev Any (3) (Mark the first THREE only) 3.2.4 (a) - Lizards of the same speciesY were used - The ratio of fire-flies to fruit-flies” - Same environmental conditions” in greenhouse structure Any (1) (Mark the first ONE only) (b) 200 insects of each were usedY (1) (Mark the first ONE only) 3.2.5 rd v x 200¥ = 120 v (3) (11) Copyright Reserved Please Turn Over ### Page 26 Downloaded from hlayiso.com Life Sci Si P2 September 2024 Preparatory Examination Whloaded from Stanporaphiysiaséncom 3.3. - Ifa population of a single species becomes separated by a geographical barrierY (sea, river, mountain, lake) - then the population splits into two” - There is now no gene flow between the two populations” - Since each population may be exposed to different environmental conditions~/the selection pressure may be different - natural selection occurs independentlyv in each of the two populations - such that the individuals of the two populations become very differentv from each other - genotypically and phenotypically” - Even if the two populations were to mix againv - they will not be able to interbreedv - The two populations are now different species” Any (6) 3.4 3.4.1 By counting the number of different insecticides that Colorado potato beetle resistedv (1) 3.4.2 - Insecticide resistance increasedv - from 1960 to 2000Y - and remained constant in 2010v (3) 3.4.3 - Buying different types of insecticidesv - will be very expensivev - leading to a greater loss of money ¥ (3) 3.4.4 - Colorado potato beetle show variation’ - Some have insecticide-resistant and others do notY - If there is an application of insecticidesY - Colorado potato beetle with resistance surviveY - whilst those without resistance died¥ - those that survive, reproducev - and pass the allele for resistance to their offspringv - The next generation will therefore have a higher proportion of Colorado potato beetle with resistancev (6) (13) Copyright Reserved Please Turn Over ### Page 27 Downloaded from hlayiso.com Life Sciggces P2 Whloaded from Stanworaphysicséncom 35 35.1 AY Rese F 4 ed A B It is longv It is shortv” Lis, Itis widev (1 mark for table + 4) only) 35:35 ar jon’ rt th = for bip v Od : turev Any 3.5.4 - Every cell has mitochondrion with DNAv - Mitochondrial DNA is only inherited through the maternal line - The analysis of mutations on the mitochondrial DNAY - shows that the oldest female ancestor was located in AfricaY - and that all humans descended from herv /mitochondrial Eve Any TOTAL SECTION B: GRAND TOTAL: Copyright Reserved September 2024 Preparatory Examination (1) (5) (2) (4) (13) [50] 100 150 ## Related documents - [Gr 12 Life Sciences P2 (English) 2024 Possible Answers](https://www.hlayiso.com/library/gr-12-life-sciences-p2-english-2024-possible-answers/056e47d6-2126-48a7-b13d-b4af9641a5a9) — Life Sciences · Memo · 2024 · Eng - 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