The document is an 11-page memorandum for a Life Sciences exam consisting of principles for marking, answers to exam questions, and a section on marking criteria. It provides concise summaries and the essential information needed to mark exam responses in 3 sentences or less.
This 10-page memorandum provides guidance for grading South African Grade 12 Life Sciences students' answers. It covers Sections A, B, and C, with Section A including multiple-choice and matching questions on topics like meiosis, genetics, and reproduction. Section B involves labelling diagrams and short questions on subjects like the male reproductive system and the menstrual cycle. Section C consists of longer essay questions on genetics, forensics, and genetically modified organisms.
This memorandum consists of 11 pages and provides answers and marking schemes for questions in Life Sciences P2 from February/March 2010. Section A contains multiple choice and short answer questions on topics such as evolution, classification of organisms, geological time periods, and human evolution. Section B involves longer answer questions on natural selection, inheritance of acquired characteristics, environmental issues, and river pollution. Section C contains questions on plant germination, data analysis, human evolution, and fisheries management. The memorandum provides detailed answers and point allocations for each question.
This document is a 10 page memorandum for a Life Sciences exam consisting of 4 sections and 15 questions. It provides the answers and explanations for each question, along with the number of marks allocated to each part. The memorandum also includes rubrics for marking diagrams and explanations. In total, there are 150 marks available for the exam.
This document provides instructions for a Life Sciences exam consisting of 15 pages with 150 marks over 2.5 hours. It instructs students to answer all questions, write answers in the answer book, number answers correctly, and do all drawings in pencil with labels in ink. Diagrams are not necessarily to scale. Students must use a non-programmable calculator, protractor, and compass where needed. The exam consists of two sections. Section A contains multiple choice, matching, and short answer questions. Section B involves labeling diagrams and short answer questions related to DNA, RNA, protein synthesis, and meiosis.
This document provides instructions for a Life Sciences exam consisting of 17 pages. It outlines that students must answer all questions, writing answers in the answer book and numbering them correctly. Diagrams should be drawn in pencil with labels in ink. Calculators and other equipment may be used. Students should write neatly and legibly. The exam is worth 150 marks and must be completed in 2.5 hours.
This memorandum consists of 11 pages and provides grading guidelines for answering questions about Life Sciences. It includes 20 principles for marking answers, such as crediting parts of responses even if the whole process isn't described. The memorandum also provides the answers to sample questions on topics like human reproduction, genetics, ecology and the human nervous and endocrine systems.
This document provides instructions for students taking the Grade 12 Life Sciences exam. It consists of three sections with a total of 150 marks over 21⁄2 hours. Students must answer all questions, writing their answers in the answer book and numbering them correctly. Diagrams should be drawn in pencil and labeled in ink. Calculators, protractors, and compasses may be used.
This document provides the memorandum for marking Life Sciences Paper 1 from November 2010 for the National Senior Certificate in South Africa. It outlines 20 principles for marking, including how to allocate marks for partial or incorrect answers. The memorandum then provides the answers and marking schemes for questions in Sections A, B and C of the paper. It gives the correct responses and number of marks awarded for each answer line or part. In total 150 marks were available for the paper.
This 10-page memorandum provides guidance for grading South African Grade 12 Life Sciences students' answers. It covers Sections A, B, and C, with Section A including multiple-choice and matching questions on topics like meiosis, genetics, and reproduction. Section B involves labelling diagrams and short questions on subjects like the male reproductive system and the menstrual cycle. Section C consists of longer essay questions on genetics, forensics, and genetically modified organisms.
This memorandum consists of 11 pages and provides answers and marking schemes for questions in Life Sciences P2 from February/March 2010. Section A contains multiple choice and short answer questions on topics such as evolution, classification of organisms, geological time periods, and human evolution. Section B involves longer answer questions on natural selection, inheritance of acquired characteristics, environmental issues, and river pollution. Section C contains questions on plant germination, data analysis, human evolution, and fisheries management. The memorandum provides detailed answers and point allocations for each question.
This document is a 10 page memorandum for a Life Sciences exam consisting of 4 sections and 15 questions. It provides the answers and explanations for each question, along with the number of marks allocated to each part. The memorandum also includes rubrics for marking diagrams and explanations. In total, there are 150 marks available for the exam.
This document provides instructions for a Life Sciences exam consisting of 15 pages with 150 marks over 2.5 hours. It instructs students to answer all questions, write answers in the answer book, number answers correctly, and do all drawings in pencil with labels in ink. Diagrams are not necessarily to scale. Students must use a non-programmable calculator, protractor, and compass where needed. The exam consists of two sections. Section A contains multiple choice, matching, and short answer questions. Section B involves labeling diagrams and short answer questions related to DNA, RNA, protein synthesis, and meiosis.
This document provides instructions for a Life Sciences exam consisting of 17 pages. It outlines that students must answer all questions, writing answers in the answer book and numbering them correctly. Diagrams should be drawn in pencil with labels in ink. Calculators and other equipment may be used. Students should write neatly and legibly. The exam is worth 150 marks and must be completed in 2.5 hours.
This memorandum consists of 11 pages and provides grading guidelines for answering questions about Life Sciences. It includes 20 principles for marking answers, such as crediting parts of responses even if the whole process isn't described. The memorandum also provides the answers to sample questions on topics like human reproduction, genetics, ecology and the human nervous and endocrine systems.
This document provides instructions for students taking the Grade 12 Life Sciences exam. It consists of three sections with a total of 150 marks over 21⁄2 hours. Students must answer all questions, writing their answers in the answer book and numbering them correctly. Diagrams should be drawn in pencil and labeled in ink. Calculators, protractors, and compasses may be used.
This document provides the memorandum for marking Life Sciences Paper 1 from November 2010 for the National Senior Certificate in South Africa. It outlines 20 principles for marking, including how to allocate marks for partial or incorrect answers. The memorandum then provides the answers and marking schemes for questions in Sections A, B and C of the paper. It gives the correct responses and number of marks awarded for each answer line or part. In total 150 marks were available for the paper.
This document provides marking guidelines for grading Life Sciences papers in South Africa. It details 20 principles for markers to follow, such as marking the first three reasons given if more than three are provided. It also notes that abbreviations must be defined and that changes to memoranda require moderator approval. The document is signed, showing moderator consensus on the policies.
This document provides instructions for a Life Sciences exam that will take place over 150 minutes. It consists of 15 pages and covers topics related to human anatomy and genetics. The exam is divided into 3 sections. Section A contains multiple choice and short answer questions. Section B focuses on human reproduction and inheritance. Section C addresses genetics concepts like inheritance patterns, genetic crosses and co-dominance. Students are instructed to answer all questions, show their work, and label diagrams clearly. Calculators and drawing tools are permitted.
The document discusses polygenic disorders, which are genetic disorders caused by more than one gene and influenced by environmental factors. They are difficult to study due to genetic variability. Two specific polygenic disorders discussed are Alzheimer's disease and diabetes/hypertension. For Alzheimer's, researchers are searching for biomarkers to detect the disease early before symptoms appear. For diabetes/hypertension, a study found that immune cells called eosinophils play an important role in regulating blood vessel function and their absence contributes to these conditions. Identifying the genetic factors for these disorders may help develop preventative measures and treatments to improve patient outcomes and quality of life.
This document provides instructions for a Life Sciences exam consisting of 3 sections worth 150 marks over 21⁄2 hours. Section A is worth 50 marks and contains multiple choice, matching, and short answer questions testing various concepts in Life Sciences. Section B is worth 30 marks and contains diagram labeling, sequencing, and longer answer questions on topics like meiosis and protein synthesis. Section C is worth 9 marks and contains labeling and short answer questions testing knowledge of the female reproductive system. The exam paper consists of 14 pages and students are instructed to answer all questions, show their work, and draw diagrams as required. Calculators and drawing tools are permitted.
This memorandum provides answers and guidance for grading a Life Sciences exam consisting of 12 pages. It includes answers to multiple choice questions, short answer questions, and longer essay questions on topics relating to human reproduction, genetics, and biotechnology. Scoring rubrics are provided for questions involving diagrams, graphs, and experimental designs. The memorandum also notes common student errors to avoid for certain questions.
This document discusses gene interaction and epistasis. It defines gene interaction as when the expression of one gene depends on the presence or absence of another gene. Epistasis occurs when one gene masks or interferes with the expression of another. There are several types of epistatic interactions including dominant epistasis, recessive epistasis, dominant inhibitory epistasis, duplicate dominant epistasis, and duplicate recessive epistasis. Examples are provided for each type.
This document provides principles for marking the Life Sciences memorandum for the 2011 National Senior Certificate Grade 12 examination. It outlines 20 principles related to marking, including how to mark answers that provide extra information, partial processes, diagrams instead of descriptions, non-recognized abbreviations, and spelling errors. It also provides guidance on marking different language responses and adhering only to approved marking memoranda.
This memorandum provides marking guidelines for Life Sciences Paper 2 for the February/March 2013 examination in South Africa. It consists of 9 pages outlining the principles for marking, answers to questions in Sections A, B and C, and allocation of marks. The memorandum addresses topics related to human reproduction, genetics, ecosystems, population ecology, and endocrine system regulation.
Wood smoke and polycyclic aromatic hydrocarbons can cause direct DNA damage through free radicals and lipid peroxidation. There are several types of DNA damage including damage from ultraviolet light, deamination, and depurination. The cell has multiple pathways to repair damaged DNA, including direct reversal, base excision repair, nucleotide excision repair, and mismatch repair. Defects in DNA repair pathways can cause genetic diseases like xeroderma pigmentosum and Cockayne syndrome. Xeroderma pigmentosum patients are highly susceptible to skin cancers due to an inability to repair UV damage.
This document is a 16-page Life Sciences question paper for Grade 12 from the February/March 2013 National Senior Certificate exams in South Africa. It consists of 4 sections with multiple choice, short answer, and longer answer questions testing knowledge of topics like genetics, evolution, and human origins. The instructions state that students have 2.5 hours to complete the paper and must answer all questions, showing their work in the provided answer book.
The human Y chromosome is much smaller than the X chromosome, containing only about 58 million base pairs and 86 genes compared to the X chromosome's 1,500 genes. Over time, most of the Y chromosome has stopped recombining with the X during meiosis, leaving only small regions at the ends that still recombine. As a result, the Y chromosome has lost over 1,300 genes and is degrading, with the potential to lose all function in 10 million years if the rate of gene loss continues. The small size and inability to recombine makes the Y chromosome highly prone to accumulating mutations and "junk DNA" with no way to remove harmful sequences.
This document discusses monosomic analysis, which is the study of plants or organisms that are missing one chromosome from their normal somatic number. It provides background on the classification of different types of monosomics, including monosomic, double monosomic, monotelosomic and more. The document also covers the history of the identification of monosomics in various species dating back to the early 1900s, as well as methods of producing monosomics like through haploids, backcrosses and irradiation. Key points covered include the cytological effects of monosomy seen during meiosis, like the presence of an unpaired univalent chromosome.
This document provides information on genetic concepts including genes, DNA, chromosomes, genotypes and phenotypes. It defines key terms and describes patterns of inheritance such as dominant, recessive, X-linked, autosomal and codominant traits. Examples are given of human genetic disorders and their inheritance patterns. Questions at the end test understanding of calculating inheritance probabilities and determining modes of inheritance from pedigree charts.
This document consists of a physics exam with multiple choice and free response questions covering topics like kinematics, density, center of mass, states of matter, and boiling vs evaporation. It contains diagrams, graphs, and calculations. The exam is 18 pages with an additional 2 blank pages for a total of 20 pages.
Gregor Johann Mendel was an Augustinian monk who conducted genetic experiments with pea plants in the 1850s and 1860s. He presented his findings in 1865, which proposed basic principles of inheritance now known as Mendel's laws of inheritance. However, his work was not widely recognized until the 1900s. Mendel's experiments involved breeding thousands of pea plants and tracking discrete traits like flower color, seed texture, and pod shape over multiple generations. His results showed dominant and recessive traits are inherited in predictable ratios and segregate independently of one another. Mendel's experiments were groundbreaking in establishing genetics as a science.
Mitochondrial DNA is typically less than 1% of an animal cell's DNA. Mitochondria contain their own genome in multiple copies that is distinct from nuclear DNA. Mitochondrial DNA is maternally inherited, circular, encodes 37 genes, and does not undergo recombination like nuclear DNA.
This document provides the marking guidelines for the 2008 Life Sciences P1 National Senior Certificate examination in South Africa. It consists of 13 pages outlining 20 key principles for marking the exam. Some of the main points include:
- Stop marking a question once the maximum marks have been reached.
- Credit all relevant parts of an answer, even if more information is provided than was asked.
- Accept answers if they are recognizable and in the correct sequence, even if spelling or language differs slightly from the guidelines.
- Credit diagrams, flow charts or tabulations if they provide the required information, even if not in the format specified.
- Be sensitive to alternative interpretations or explanations provided in answers.
This document summarizes several pedigree analyses involving inheritance patterns of traits:
1. A pedigree is presented where a woman has a 100% chance of passing on a defective gene to her daughter based on her genotype. Calculations are shown for determining the probability that her grandson will have the defective gene.
2. Multiple pedigrees demonstrate autosomal recessive inheritance patterns based on affected and unaffected family members. X-linked inheritance is ruled out.
3. The mode of inheritance is determined to be autosomal recessive for a pedigree where an affected mother passes the trait to all her children. Mitochondrial inheritance and variable expression are discussed.
4. Probabilities are calculated for heterozygous parents and
Features of multiple alleles. The same genes have more than two alleles. All multiple alleles in homologous chromosomes occupy the respective loci. A chromosome or gamete only has one group allele. Each human contains only two separate gene alleles, one for each homologous pair of chromosomes carrying the gene.
More than two alternative alleles of a gene are known as multiple alleles in a population occupying the same locus on a chromosome or its homologue. ... Multiple alleles express various alternatives of one trait. Different alleles can exhibit codominance, dominance-recessive behaviour or incomplete dominance.
This document contains assessment exemplars for Life Sciences for Grade 10, including control tests, a research project, and practical tasks. It provides teacher guidelines, assessment rubrics, and worksheets for learners for each assessment. The introductions explain that the exemplars are meant to be used for continuous assessment throughout the year. They assess the three learning outcomes, with the tests and project assessing mastery of content and skills, and the practical tasks assessing skills. Guidelines are provided for implementing the research project and practical activities, including classroom management, technology use, and thinking strategies.
This document contains instructions for a Grade 12 Life Sciences exam. It consists of 17 pages and students have 2.5 hours to complete it. The exam contains multiple choice questions, terminology questions, matching questions and short answer questions testing knowledge of human anatomy and physiology, genetics, ecology and other topics. Students must answer all questions in the answer book provided and show all working where required. Diagrams should be drawn in pencil. Calculators and other aids are permitted.
This document provides marking guidelines for grading Life Sciences papers in South Africa. It details 20 principles for markers to follow, such as marking the first three reasons given if more than three are provided. It also notes that abbreviations must be defined and that changes to memoranda require moderator approval. The document is signed, showing moderator consensus on the policies.
This document provides instructions for a Life Sciences exam that will take place over 150 minutes. It consists of 15 pages and covers topics related to human anatomy and genetics. The exam is divided into 3 sections. Section A contains multiple choice and short answer questions. Section B focuses on human reproduction and inheritance. Section C addresses genetics concepts like inheritance patterns, genetic crosses and co-dominance. Students are instructed to answer all questions, show their work, and label diagrams clearly. Calculators and drawing tools are permitted.
The document discusses polygenic disorders, which are genetic disorders caused by more than one gene and influenced by environmental factors. They are difficult to study due to genetic variability. Two specific polygenic disorders discussed are Alzheimer's disease and diabetes/hypertension. For Alzheimer's, researchers are searching for biomarkers to detect the disease early before symptoms appear. For diabetes/hypertension, a study found that immune cells called eosinophils play an important role in regulating blood vessel function and their absence contributes to these conditions. Identifying the genetic factors for these disorders may help develop preventative measures and treatments to improve patient outcomes and quality of life.
This document provides instructions for a Life Sciences exam consisting of 3 sections worth 150 marks over 21⁄2 hours. Section A is worth 50 marks and contains multiple choice, matching, and short answer questions testing various concepts in Life Sciences. Section B is worth 30 marks and contains diagram labeling, sequencing, and longer answer questions on topics like meiosis and protein synthesis. Section C is worth 9 marks and contains labeling and short answer questions testing knowledge of the female reproductive system. The exam paper consists of 14 pages and students are instructed to answer all questions, show their work, and draw diagrams as required. Calculators and drawing tools are permitted.
This memorandum provides answers and guidance for grading a Life Sciences exam consisting of 12 pages. It includes answers to multiple choice questions, short answer questions, and longer essay questions on topics relating to human reproduction, genetics, and biotechnology. Scoring rubrics are provided for questions involving diagrams, graphs, and experimental designs. The memorandum also notes common student errors to avoid for certain questions.
This document discusses gene interaction and epistasis. It defines gene interaction as when the expression of one gene depends on the presence or absence of another gene. Epistasis occurs when one gene masks or interferes with the expression of another. There are several types of epistatic interactions including dominant epistasis, recessive epistasis, dominant inhibitory epistasis, duplicate dominant epistasis, and duplicate recessive epistasis. Examples are provided for each type.
This document provides principles for marking the Life Sciences memorandum for the 2011 National Senior Certificate Grade 12 examination. It outlines 20 principles related to marking, including how to mark answers that provide extra information, partial processes, diagrams instead of descriptions, non-recognized abbreviations, and spelling errors. It also provides guidance on marking different language responses and adhering only to approved marking memoranda.
This memorandum provides marking guidelines for Life Sciences Paper 2 for the February/March 2013 examination in South Africa. It consists of 9 pages outlining the principles for marking, answers to questions in Sections A, B and C, and allocation of marks. The memorandum addresses topics related to human reproduction, genetics, ecosystems, population ecology, and endocrine system regulation.
Wood smoke and polycyclic aromatic hydrocarbons can cause direct DNA damage through free radicals and lipid peroxidation. There are several types of DNA damage including damage from ultraviolet light, deamination, and depurination. The cell has multiple pathways to repair damaged DNA, including direct reversal, base excision repair, nucleotide excision repair, and mismatch repair. Defects in DNA repair pathways can cause genetic diseases like xeroderma pigmentosum and Cockayne syndrome. Xeroderma pigmentosum patients are highly susceptible to skin cancers due to an inability to repair UV damage.
This document is a 16-page Life Sciences question paper for Grade 12 from the February/March 2013 National Senior Certificate exams in South Africa. It consists of 4 sections with multiple choice, short answer, and longer answer questions testing knowledge of topics like genetics, evolution, and human origins. The instructions state that students have 2.5 hours to complete the paper and must answer all questions, showing their work in the provided answer book.
The human Y chromosome is much smaller than the X chromosome, containing only about 58 million base pairs and 86 genes compared to the X chromosome's 1,500 genes. Over time, most of the Y chromosome has stopped recombining with the X during meiosis, leaving only small regions at the ends that still recombine. As a result, the Y chromosome has lost over 1,300 genes and is degrading, with the potential to lose all function in 10 million years if the rate of gene loss continues. The small size and inability to recombine makes the Y chromosome highly prone to accumulating mutations and "junk DNA" with no way to remove harmful sequences.
This document discusses monosomic analysis, which is the study of plants or organisms that are missing one chromosome from their normal somatic number. It provides background on the classification of different types of monosomics, including monosomic, double monosomic, monotelosomic and more. The document also covers the history of the identification of monosomics in various species dating back to the early 1900s, as well as methods of producing monosomics like through haploids, backcrosses and irradiation. Key points covered include the cytological effects of monosomy seen during meiosis, like the presence of an unpaired univalent chromosome.
This document provides information on genetic concepts including genes, DNA, chromosomes, genotypes and phenotypes. It defines key terms and describes patterns of inheritance such as dominant, recessive, X-linked, autosomal and codominant traits. Examples are given of human genetic disorders and their inheritance patterns. Questions at the end test understanding of calculating inheritance probabilities and determining modes of inheritance from pedigree charts.
This document consists of a physics exam with multiple choice and free response questions covering topics like kinematics, density, center of mass, states of matter, and boiling vs evaporation. It contains diagrams, graphs, and calculations. The exam is 18 pages with an additional 2 blank pages for a total of 20 pages.
Gregor Johann Mendel was an Augustinian monk who conducted genetic experiments with pea plants in the 1850s and 1860s. He presented his findings in 1865, which proposed basic principles of inheritance now known as Mendel's laws of inheritance. However, his work was not widely recognized until the 1900s. Mendel's experiments involved breeding thousands of pea plants and tracking discrete traits like flower color, seed texture, and pod shape over multiple generations. His results showed dominant and recessive traits are inherited in predictable ratios and segregate independently of one another. Mendel's experiments were groundbreaking in establishing genetics as a science.
Mitochondrial DNA is typically less than 1% of an animal cell's DNA. Mitochondria contain their own genome in multiple copies that is distinct from nuclear DNA. Mitochondrial DNA is maternally inherited, circular, encodes 37 genes, and does not undergo recombination like nuclear DNA.
This document provides the marking guidelines for the 2008 Life Sciences P1 National Senior Certificate examination in South Africa. It consists of 13 pages outlining 20 key principles for marking the exam. Some of the main points include:
- Stop marking a question once the maximum marks have been reached.
- Credit all relevant parts of an answer, even if more information is provided than was asked.
- Accept answers if they are recognizable and in the correct sequence, even if spelling or language differs slightly from the guidelines.
- Credit diagrams, flow charts or tabulations if they provide the required information, even if not in the format specified.
- Be sensitive to alternative interpretations or explanations provided in answers.
This document summarizes several pedigree analyses involving inheritance patterns of traits:
1. A pedigree is presented where a woman has a 100% chance of passing on a defective gene to her daughter based on her genotype. Calculations are shown for determining the probability that her grandson will have the defective gene.
2. Multiple pedigrees demonstrate autosomal recessive inheritance patterns based on affected and unaffected family members. X-linked inheritance is ruled out.
3. The mode of inheritance is determined to be autosomal recessive for a pedigree where an affected mother passes the trait to all her children. Mitochondrial inheritance and variable expression are discussed.
4. Probabilities are calculated for heterozygous parents and
Features of multiple alleles. The same genes have more than two alleles. All multiple alleles in homologous chromosomes occupy the respective loci. A chromosome or gamete only has one group allele. Each human contains only two separate gene alleles, one for each homologous pair of chromosomes carrying the gene.
More than two alternative alleles of a gene are known as multiple alleles in a population occupying the same locus on a chromosome or its homologue. ... Multiple alleles express various alternatives of one trait. Different alleles can exhibit codominance, dominance-recessive behaviour or incomplete dominance.
This document contains assessment exemplars for Life Sciences for Grade 10, including control tests, a research project, and practical tasks. It provides teacher guidelines, assessment rubrics, and worksheets for learners for each assessment. The introductions explain that the exemplars are meant to be used for continuous assessment throughout the year. They assess the three learning outcomes, with the tests and project assessing mastery of content and skills, and the practical tasks assessing skills. Guidelines are provided for implementing the research project and practical activities, including classroom management, technology use, and thinking strategies.
This document contains instructions for a Grade 12 Life Sciences exam. It consists of 17 pages and students have 2.5 hours to complete it. The exam contains multiple choice questions, terminology questions, matching questions and short answer questions testing knowledge of human anatomy and physiology, genetics, ecology and other topics. Students must answer all questions in the answer book provided and show all working where required. Diagrams should be drawn in pencil. Calculators and other aids are permitted.
This document shows demonstration of a heart dissection, if the teacher wishes to this practical he/she should moderate the learners so that they don't hurt themselves
This 10-page memorandum provides marking guidelines for a Life Sciences P2 examination consisting of 150 marks. It details 20 marking principles, including how to mark answers that provide more information than required or have sequencing and language issues. The memorandum then provides answer keys for 50 marks of section A multiple choice and structured questions, 60 marks of section B short answer and diagram labeling questions, and 40 marks of section C essay questions on topics like population growth and endocrine system function.
This 10-page memorandum provides marking guidelines for a Life Sciences P1 exam consisting of 150 marks and taken by full-time candidates in February/March 2013. It outlines 20 principles related to marking, including how to mark answers that provide more or less information than required or have incorrect sequencing. The memorandum also provides answer keys and mark allocations for 4 sections worth a total of 150 marks. Section A covers multiple choice, terminology, and genetics inheritance questions. Section B addresses DNA structure, sex-linked inheritance, protein synthesis, and meiosis. Section C involves human evolution topics and a graphing activity. Section D covers genetics principles like phenotypes and genotypes.
This memorandum provides guidelines for marking the 2011 Life Sciences Paper 2 for the National Senior Certificate in South Africa. It consists of 20 principles to ensure consistent and fair marking. Some key principles include: awarding marks for the first few reasons/examples provided, even if incorrect; accepting answers that demonstrate understanding despite differences in format; and not penalizing for spelling errors if the word is recognizable. The memorandum also provides mark allocations for each question and sub-question.
This document provides instructions for a Life Sciences exam. It consists of 15 pages and students have 2.5 hours to complete it. The instructions state that students must answer all questions, write answers in the answer book provided, number answers according to the question paper, present drawings according to instructions, and write neatly. It also provides information about the number of marks allocated, use of calculators and drawing tools, and copyright notice.
This document provides examination guidelines for the Grade 12 Life Sciences exam in South Africa. It consists of 19 pages covering: the format and weighting of the exam papers; the formal assessment program and sequence of topics; and an elaboration of the content to be assessed for each topic, including DNA, meiosis, reproduction, genetics and inheritance. The topics will be assessed across two question papers that contain short answers, structured questions and an essay. The guidelines are intended to clarify the scope of the exam and assist teachers in preparing learners.
The memorandum provides principles for marking Life Sciences papers in 2012. It details 20 marking principles, including crediting relevant parts of answers even if extra information is provided, marking the first few reasons or examples given, and being sensitive to answers stated differently but conveying the same meaning. The memorandum also addresses aspects like spelling, abbreviations, diagrams, flow charts, and language.
Mitosis is the process of cell division that results in two daughter cells with identical genetic material as the parent cell. It occurs in eukaryotic cells and has five stages: interphase, prophase, metaphase, anaphase, and telophase. During interphase the cell grows and duplicates its DNA. In prophase the chromosomes condense and become visible. Metaphase involves the chromosomes aligning at the center of the cell. Anaphase separates the sister chromatids so that each daughter cell receives one set. Telophase involves the division of the cytoplasm and formation of new cell membranes. Mitosis plays an important role in growth, regeneration, and cell replacement. Errors can result in genetic mutations.
The document summarizes human reproduction. It describes sexual reproduction involving the fusion of egg and sperm cells. The male reproductive system produces sperm in the testes and transfers them through the penis during intercourse. The female reproductive system involves ovaries releasing eggs, fallopian tubes and uterus where fertilization and fetal development occur. The menstrual cycle and process of fertilization are also outlined.
This memorandum provides marking guidelines for Life Sciences Paper 2. It consists of 20 pages detailing the answers and marks allocated for each question. Principles for marking include stopping when maximum marks are reached, marking the first answer if more than required are given, and crediting relevant parts of longer answers. Abbreviations must be defined to receive marks. Diagrams or flow charts lose marks if descriptions are required.
This document contains a biology exam for 9th grade students with 40 multiple choice questions covering various topics like cells, transport in plants, human anatomy and physiology, enzymes, respiration, excretion, homeostasis and digestion. The exam is divided into sections with diagrams, graphs, tables and questions. It provides instructions for students on completing the multiple choice answer sheet within the 1 hour time limit.
Additional Language
4.5
Mathematics
4.5
Life Sciences
4
Physical Sciences
4
Social Sciences
4
Economic and Management Sciences
4
Technology
4
Computer Applications Technology (CAT)
2
Creative Arts
2
Life Orientation
2
Physical Education
2
Elective Subjects
(maximum 3 electives can be taken)
2 each
CAPS
7
LIFE SCIENCES GRADES 10-12
SECTION 2
INTRODUCTION TO LIFE SCIENCES
2.1 What is Life
This document provides instructions for a Grade 12 Life Sciences exam. It consists of 14 pages and students have 2.5 hours to complete it. The exam contains 3 sections. Section A has 10 multiple choice questions worth 1 or 2 marks each, and short answer questions worth 1-8 marks. Section B contains diagram and graph interpretation questions worth 1-14 marks. Section C involves investigating the resistance of mosquitoes to DDT over time, with associated graphing and analysis questions worth 1-6 marks. Students are instructed to show all working, use scientific terms correctly, and answer all questions in full sentences in the answer book provided.
Mitosis is a process of cell division where one cell splits into two identical daughter cells. It allows for organism growth and repair of damaged tissues. The key stages are interphase, prophase, metaphase, anaphase and telophase. In interphase, the cell grows and its DNA is replicated. The other phases involve the condensing and separating of chromosomes and splitting of the cell contents until two identical daughter cells are formed. Mitosis is important for reproduction, growth, and repair in many organisms.
This document outlines the curriculum and assessment policy for Life Sciences in grades 10-12 in South African schools. It aims to heal divisions of the past and establish a society based on democratic values of social justice, human rights, and improved quality of life. The curriculum covers core content in Life Sciences including cell biology, genetics, evolution, ecology, and human impacts. It assesses students' knowledge of concepts as well as their ability to investigate phenomena and appreciate the importance of Life Sciences in society. Formal assessment includes tests, examinations, practical tasks, and investigations conducted throughout grades 10-12.
This document outlines the curriculum and assessment policy for Life Sciences in grades 10-12 in South African schools. It aims to heal divisions of the past and establish a society based on democratic values of social justice, human rights, and improved quality of life. The curriculum covers core content in Life Sciences including cell biology, genetics, evolution, ecology, and human impacts. It emphasizes developing scientific knowledge and skills through investigation of phenomena. Time and resources are allocated for teaching Life Sciences and formal assessments are outlined for each grade to measure learning outcomes.
Grade 10 Science Learner' Material Unit 2-Force, Motion and EnergyJudy Aralar
Here are the instructions for Activity 1:
Part A: Virtual Tour of a Radio Broadcasting Studio
1. Using the internet, search for images and videos of a typical radio broadcasting studio. Take note of the equipment and devices used.
2. Identify the basic equipment and devices used in a radio studio for recording and broadcasting audio programs. Some examples are microphones, mixing console, recording devices, playback devices, etc.
3. Classify whether each device uses electricity, magnetism or both based on its function. You may need to do additional research.
4. Take screenshots of the studio setup and label the basic equipment.
Part B: My Own Home Recording Studio! For Life
1. Imagine putting together
This document is the cover page for a Life Sciences exam consisting of 16 pages. It provides instructions for candidates taking the exam, including answering all questions, writing answers in the answer book, numbering answers correctly, presenting answers as instructed, using pencil for drawings, only drawing diagrams when asked, and writing neatly. It also allows for the use of a calculator, protractor, and compass where necessary.
The document provides instructions for the National Entrance Screening Test (NEST) to be held on 2014. It details that the test will be 3 hours long and contain 5 sections worth 50 marks each. One of the sections is general and students must attempt it along with 3 of the 4 subject sections. Calculators and electronic devices are not allowed. Answers must be marked on an optical mark recognition (OMR) sheet using the provided code. The document also provides some useful physical constants and the atomic masses of some elements as reference.
This document provides a summary of the key points from a biology exam marking scheme:
1. The marking scheme provides guidance for examiners on how to award marks to student responses on a biology exam covering topics like digestion, genetics, and ecosystems.
2. Detailed answers and notes are provided for multiple choice and longer answer questions testing understanding of concepts such as cell division, heart disease risk factors, and genetic inheritance of traits.
3. Mark allocations are given for each sub-part of longer questions to help examiners accurately assess and score different aspects of student answers.
This document provides a summary of the key points from the given text:
1. The document is a mark scheme that evaluates exam questions on biology and science subjects. It provides sample answers and notes for multiple choice and structured questions.
2. The mark scheme covers topics related to biology, such as digestion, cell division, genetics, ecosystems and human physiology.
3. Detailed answers are given marks based on how well they address the learning points or processes outlined in the exam questions. Partial or incomplete responses receive fewer marks.
This document provides instructions for a Life Sciences exam consisting of 13 pages and 150 marks over 2.5 hours. It is divided into 3 sections. Section A contains multiple choice and matching questions about topics in evolution, genetics, human origins, and inheritance patterns. Section B asks students to represent genetic crosses, discuss advantages and disadvantages of genetic engineering, and interpret data on human height. Section C contains diagrams of skulls and asks students to identify species, compare evolutionary trends, and describe evidence for the African origin of humans.
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This document provides a mark scheme for Pearson Edexcel's International GCSE in Biology exam. It outlines the general marking guidance which instructs examiners to mark candidates positively and according to the mark scheme. It also notes that all marks on the mark scheme should be awarded if deserved. The mark scheme then provides the answers and notes for six exam questions and assigns marks to different parts of the answers.
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This document provides instructions for a Life Sciences exam consisting of three sections worth a total of 150 marks over 21⁄2 hours. Section A is worth 50 marks and includes multiple choice, matching, and short answer questions testing concepts in evolution, ecology and microbiology. Section B is worth 30 marks for each of two structured questions on topics like pollution indicators, deforestation, and comparative anatomy. Section C consists of an essay worth 40 marks. Students are instructed to answer all questions, show workings, use diagrams where required, and write neatly.
Class 12 Cbse Biology Sample Paper 2012-13Sunaina Rawat
- Develop extensive root systems to absorb water from deeper soil layers.
du
- Have thick cuticle and sunken stomata to reduce transpiration.
- Possess water storage tissues like succulents.
.e
- Droop or shed leaves during drought.
w
w
Animals:
- Migrate to areas with available water.
w
- Enter state of aestivation or hibernation during drought.
- Concentrate urine to reduce water loss.
- Obtain water from metabolic processes like respiration.
28. (a) Labelled diagram of sectional view of human ovary showing:
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This document provides instructions for a laboratory activity on evolution. The activity has two parts: (1) distinguishing heritable and non-heritable traits within populations using published data on different species, and (2) simulating natural selection on a population of sticks of different colors scattered in different environments. Students are asked to record data on initial and final population counts and proportions, perform statistical tests to analyze changes, and answer questions about heritability of traits, natural selection, and fitness of different individuals.
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BIOL4417/5517:OrganicEvolution Fall2018
DueFridayOctober12,2018at5:00PM
Mid-TermExam
This is a take-home exam: use your text, notes and other materials to prepare your answers. You may discuss
questions with classmates but must write your answers independently. Although factual, accurate answers are
expected, much of your grade will depend upon the thoughtfulness and creativity of your answers. Concise,
complete & grammatically correct sentences are essential; references are allowed but not required. Please
number your answers using the question numbers (otherwise, your grader will get confused).
The exam is due Friday October 12 at 5:00 PM, submitted on the Moodle website.
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tences). Solve BOTH of the problems. 5 points each. Read each question carefully.
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largely determined at the K-locus by the alleles A1 and A2. Yellowstone wolves with genotype A1A1 have the
black coat beneficial for hunting in forested ecosystems; fitness of W11 = 0.80. Wolves with the genotype
A2A2 have the gray coat normally found in open tundra ecosystems; W22 = 0.75. Wolves A1A2 are interme-
diate for coat color; W12 = 1.0. At equilibrium, what will be the frequencies of the A1 allele and the three
genotypes? Show all work and fully justify your answer.
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cient mutation that introduced a neutral allele, T2: individuals with T1T2 have somewhat less white teeth
and those with T2T2 have substantially less white teeth. Although initially only found in one individual, after
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generations, q = 0.55. What is the probability today that the neutral T2 will eventually become fixed in
the population? Show all work and justify your answer.
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lapagos and on their way to a Halloween party. A storm blew in and redirected the birds to an island that
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es, collects feathers for a genetic analysis, and finds that this isolated population of vampire ground finches
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might thi.
Tetrad analysis is a technique used to study genetic linkage in fungi and other lower eukaryotes. During meiosis in these organisms, four haploid spores, known as a tetrad, are produced. If spores remain in ordered linear formations, called ordered tetrads, the arrangement allows mapping of genes relative to centromeres. If spores are randomly mixed in unordered tetrads, patterns of allele segregation can determine if two genes are linked. Analysis of tetrad segregation patterns is used to calculate genetic distance between loci.
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This document contains a sample of 20 multiple choice questions from a practice test for the NEET 2019 exam. The questions cover topics in biology, chemistry and general science. For each question, the correct answer is provided along with a brief explanation or hint. The questions range in difficulty and cover topics such as genetics, plants, animals, the human body and cell biology.
Similar to Life sciences p2 gr 12 exemplar 2014 eng memo (17)
1. The document defines evolution as gradual changes in organisms over generations due to natural selection. It discusses key figures in the development of evolutionary theory like Lamarck, Darwin, and Wallace.
2. Mechanisms of evolution include genetic variation, inheritance of traits, natural selection of advantageous variations, and accumulation of small changes over long periods of time leading to new species.
3. Evidence for evolution comes from fossils that show gradual changes in ancient species over millions of years, as well as anatomical, genetic, and biochemical similarities between living and extinct species, indicating common ancestry.
1) Fossil evidence from sites in South Africa like Sterkfontein provide insight into early hominids that lived over 3 million years ago, including Australopithecus africanus.
2) As hominids evolved, they exhibited skeletal changes associated with bipedalism as well as increases in brain size and cultural adaptations like tool use.
3) Genetic and fossil evidence supports the 'Out of Africa' theory where modern humans evolved in Africa around 200,000 years ago and migrated elsewhere, replacing earlier hominid species like Neanderthals.
Meiosis is a cell division process that produces gametes, or sex cells, with half the normal number of chromosomes. It occurs in two stages: Meiosis I splits homologous chromosome pairs, resulting in haploid cells, and Meiosis II splits the remaining sister chromatids into individual chromosomes, resulting in four haploid cells. This ensures that offspring receive a mixture of maternal and paternal chromosomes and introduces genetic variation through processes like crossing over during prophase I. Meiosis is essential for sexual reproduction, as it maintains the chromosome number between generations and produces genetic diversity in offspring.
This document discusses genetics and inheritance of genetic diseases. It covers Gregor Mendel's experiments with pea plants which laid the foundations of genetics, including genes, alleles, dominant and recessive traits. It also discusses chromosomes, genetic crosses, sex-linked inheritance and examples of genetic disorders like cystic fibrosis and muscular dystrophy. The role of mutations in causing genetic diseases as well as the process of genetic counseling is summarized.
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This document discusses speciation and the factors that can lead to the formation of new species. It outlines two main types of speciation: allopatric speciation which is caused by geographic isolation, and sympatric speciation which does not require a large geographic barrier. Factors that can influence speciation include genetic variation due to isolation, inbreeding within small isolated populations, outbreeding between unrelated individuals, founder effects in small groups colonizing new areas, population bottlenecks from catastrophic events, and reproductive isolation through mechanisms like breeding at different times or adapting to different pollinators.
(1) This document provides instructions for a Life Sciences exam consisting of 3 sections with multiple choice, matching, and short answer questions. It gives the time allotted, 150 marks, and details that all answers must be written in the answer book and drawings done in pencil.
(2) Section A includes 7 multiple choice questions testing content knowledge, 7 short answer questions requiring biological terms, and 6 matching questions. Section B has short answer questions on evolution, adaptations, natural selection, and speciation. Section C addresses disease transmission, resource use, and human evolution.
This document is a 16-page Life Sciences question paper for Grade 12 students taking a test. It consists of various multiple choice and short answer questions testing knowledge of topics like sexual reproduction, population ecology, human physiology, and more. The questions are formatted in numbered sections and subsections, with space provided to write answers directly in the test booklet.
This document provides instructions for a Life Sciences exam consisting of 150 marks over 2.5 hours. It is divided into three sections: Section A with 50 marks, Section B with 60 marks, and Section C with 40 marks. The paper contains various types of questions including multiple choice, matching columns, labeling diagrams, short answers and longer explanations. Students are instructed to answer all questions in their answer book and show all working where necessary. They are permitted to use a calculator, protractor and compass during the exam.
This document is a 16-page exam paper for Life Sciences P2 from February/March 2010. It contains instructions for the exam, which is divided into two sections worth a total of 150 marks and takes 2.5 hours. Section A contains multiple choice and short answer questions testing concepts related to evolution, ecology, genetics and the timeline of life on Earth. Section B includes several longer answer questions requiring explanations and descriptions related to topics like natural selection, Lamarckism, water pollution and plant uses.
This document contains instructions for a 150 mark, 2.5 hour Life Sciences exam for Grade 12. It outlines:
- The number of questions and pages in the paper
- Instructions that students must answer all questions, write answers in the answer book, and number them correctly
- Information on drawings, diagrams, and materials allowed
- The exam contains 3 sections: Section A with 7 multiple choice and descriptive questions worth 50 marks, Section B with 4 extended response questions worth 30 marks, and Section C with 1 extended response question worth 30 marks.
1. Copyright reserved Please turn over
MARKS: 150
This memorandum consists of 11 pages.
LIFE SCIENCES P2
EXEMPLAR 2014
MEMORANDUM
NATIONAL
SENIOR CERTIFICATE
GRADE 12
2. Life Sciences/P2 2 DBE/2014
NSC – Grade 12 Exemplar – Memorandum
Copyright reserved Please turn over
PRINCIPLES RELATED TO MARKING LIFE SCIENCES
1. If more information than marks allocated is given
Stop marking when maximum marks is reached and put a wavy line and 'max' in the right-hand margin.
2. If, for example, three reasons are required and five are given
Mark the first three irrespective of whether all or some are correct/incorrect.
3. If whole process is given when only a part of it is required
Read all and credit the relevant part.
4. If comparisons are asked for but descriptions are given
Accept if the differences/similarities are clear.
5. If tabulation is required but paragraphs are given
Candidates will lose marks for not tabulating.
6. If diagrams are given with annotations when descriptions are required
Candidates will lose marks.
7. If flow charts are given instead of descriptions
Candidates will lose marks.
8. If sequence is muddled and links do not make sense
Where sequence and links are correct, credit. Where sequence and links are incorrect, do not credit. If sequence and links become correct again, resume credit.
9. Non-recognised abbreviations
Accept if first defined in answer. If not defined, do not credit the unrecognised abbreviation but credit the rest of the answer if correct.
10. Wrong numbering
If answer fits into the correct sequence of questions but the wrong number is given, it is acceptable.
11. If language used changes the intended meaning
Do not accept.
12. Spelling errors
If recognisable, accept the answer, provided it does not mean something else in Life Sciences or if it is out of context.
13. If common names are given in terminology
Accept, provided it was accepted at the national memo discussion meeting.
14. If only the letter is asked for but only the name is given (and vice versa)
Do not credit.
3. Life Sciences/P2 3 DBE/2014
NSC – Grade 12 Exemplar – Memorandum
Copyright reserved Please turn over
15. If units are not given in measurements
Candidates will lose marks. Memorandum will allocate marks for units separately.
16. Be sensitive to the sense of an answer, which may be stated in a different way.
17. Caption
All illustrations (diagrams, graphs, tables, etc.) must have a caption.
18. Code-switching of official languages (terms and concepts)
A single word or two that appear(s) 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.
19. Changes to the memorandum
No changes must be made to the memoranda without consulting the provincial internal moderator who in turn will consult with the national internal moderator (and the Umalusi moderators where necessary).
20. Official memoranda
Only memoranda bearing the signatures of the national internal moderator and the Umalusi moderators and distributed by the National Department of Basic Education via the provinces must be used.
4. Life Sciences/P2 4 DBE/2014
NSC – Grade 12 Exemplar – Memorandum
Copyright reserved Please turn over
SECTION A
QUESTION 1
1.1
1.1.1
1.1.2
1.1.3
1.1.4
1.1.5
1.1.6
1.1.7
1.1.8
1.1.9
1.1.10
A
B
A
A
D
C
D
B
B
B
(10 x 2)
(20)
1.2
1.2.1
Recessive
1.2.2
Locus
1.2.3
Phenotype
1.2.4
Autosomes
1.2.5
1.2.6
Genetic engineering/DNA manipulation/
Biotechnology/DNA recombination
Chromatids (6 x 1)
(6)
1.3
1.3.1
1.3.2
1.3.3
1.3.4
1.3.5
1.3.6
1.3.7
1.3.8
Both A and B
A only
B only
A only
B only
A only
None
B only (8 x 2)
(16)
1.4
1.4.1
1.4.2
1.4.3
1.4.4
(a) RrYy
(b) rryy
RY, Ry, rY, ry
(a) Wrinkled, yellow seeds
(b) Round, yellow seeds
RRYY
(1)
(1)
(2)
(1)
(1)
(2)
(8)
[50]
5. Life Sciences/P2 5 DBE/2014
NSC – Grade 12 Exemplar – Memorandum
Copyright reserved Please turn over
QUESTION 2
2.1
2.1.1
(a) DNA
(b) Ribosome
(1)
(1)
2.1.2
(a) G
(b) U
(1)
(1)
2.1.3
2.1.4
2.1.5
− DNA codes for a particular protein but cannot leave nucleus
− One strand of DNA is used as a template
− to form mRNA
− According to the codons on mRNA
− tRNA molecules with matching anticodons
− bring the required amino acids to the ribosome
− This is called translation
− The amino acids become attached by peptide bonds
− to form the required protein (any 4)
Methionine, Glycine, Arginine (in the correct order)
(3)
(4)
(3)
(14)
2.2
2.2.1
2.2.2
H. erectus
A. afarensis
(1)
(1)
2.2.3
2.2.4
(a) 3 mya – 2,4 mya = 0,6 my
OR
3 mya – 2,3 mya = 0,7 my
(b) Fossils
(a) H. neanderthalensis
(b) H. neanderthalensis and H. sapiens share a common ancestor
OR
Both evolved from H heidelbergensis
(3)
(1)
(1)
(2)
(2)
(9)
6. Life Sciences/P2 6 DBE/2014
NSC – Grade 12 Exemplar – Memorandum
Copyright reserved Please turn over
2.3
2.3.1
− The homologous chromosome pair
− does not separate/non-disjunction
− during anaphase 1
(3)
2.4
2.4.1
Diagram 1
(1)
2.4.2
Diagrams 2 & 3/ 2 & 4/ 3 & 4
(2)
2.4.3
Analogous structures show that two organisms evolved independently of each other
Homologous structures show that two organisms have a common ancestor.
(2)
(5)
[40]
2.3.2
1
(1)
2.3.3
Down syndrome
(1)
2.3.4
− During crossing over
− in Prophase 1
− segments of chromatids of homologous chromosomes
− are exchanged
− leading to each gamete having a mix of genetic material from both parents (any 4)
− During Metaphase I/II
− each pair of homologous chromosomes/each chromosome
− may line up in different ways on the equator of the spindle
− allowing the gametes to have different combinations of maternal and paternal chromosomes (any 3)
(7)
(12)
7. Life Sciences/P2 7 DBE/2014
NSC – Grade 12 Exemplar – Memorandum
Copyright reserved Please turn over
3.1
3.1.1
(a) Time
(b) Mortality of mosquitoes
(1)
(1)
3.1.2
3.1.3
Mosquito Mortality due to DDT/Resistance of mosquitos to DDT will decrease over time
OR
Mosquito Mortality due to DDT/Resistance of mosquitos to DDT will increase over time
OR
Mosquito Mortality due to DDT/Resistance of mosquitos to DDT will remain the same over time
(3)
NOTE:
If the wrong type of graph is drawn:
- Marks will be lost for 'correct type of graph'
If axes are transposed:
- Marks will be lost for labelling of X-axis and Y-axis
QUESTION 3
Time (months)
8. Life Sciences/P2 8 DBE/2014
NSC – Grade 12 Exemplar – Memorandum
Copyright reserved Please turn over
Mark allocation for the graph
Criterion
Elaboration
Mark
Type of graph
Line graph drawn
1
Caption
Includes both variables: 'Percentage mortality of mosquitoes' and 'Time'
1
X-axis
Appropriate scale AND
Correct label and units for X-axis: Time (months)
1
Y-axis
Appropriate scale AND
Correct label and units for Y-axis: Mortality of mosquitoes (%)
1
Plotting of points
1–8 points plotted correctly – 1 mark
All 9 points plotted correctly – 2 marks
2
(6)
3.1.4
3.1.5
3.1.6
− Same species of mosquito
− Identical laboratory conditions for the full period of the investigation
− The same scientist must be used for the full period of the investigation
− Mosquitos should not be hurt for the full period of the investigation
(Mark first TWO only) (any 2)
− Use a larger sample of mosquitoes
− Repeat the investigation
− Take many samples each time and calculate the average mortality
(Mark first TWO only) (any 2)
− More mosquitoes are produced than can survive.
− There is genetic variation amongst the mosquitoes.
− Some mosquitoes may be naturally resistant to DDT.
− When DDT is applied
− those that are resistant survive
− and they then reproduce,
− passing the allele for resistance to the offspring.
− Those that are not resistant, die
− and their alleles are lost from the population.
− The number of DDT-resistant mosquitoes therefore increases over the generations. (any 8)
(2)
(2)
(8)
(23)
3.2
3.2.1
The oldest fossils of human ancestors were only found in Africa
(2)
3.2.2
− Mitochondrial DNA is passed down from mother to child
− mutations on the mitochondrial DNA
− were traced to an ancestral female that existed in Africa
(3)
(5)
9. Life Sciences/P2 9 DBE/2014
NSC – Grade 12 Exemplar – Memorandum
Copyright reserved Please turn over
3.3.3
P1 phenotype Normal female x Normal male
genotype XDXd x XDY
Meiosis
G1 XD , Xd x XD , Y
Fertilisation
XDXD,
XDXd,
XDY,
XdY
F1 genotype
phenotype
2 normal females
1 normal male
1 colour- blind male
Parents and offspring/P1 & F1
Meiosis and fertilisation (any 6)
OR
P1/parent phenotype Grey bodied x grey bodied
genotype Gg x Gg
Meiosis
Fertilisation
F1 genotype
phenotype
2 normal females
1 normal male
1 colour- blind male
Parents and offspring/P1 & F1
Meiosis and fertilisation (any 6)
TOTAL SECTION B:
(6)
(12)
[40]
80
3.3
3.3.1
(a) XdXd
(b) XDY
(2)
(2)
3.3.2
3
(2)
gametes
XD
Xd
XD
XDXD
XDXd
Y
XDY
XdY
1 mark for correct gametes 1 mark for correct genotypes
10. Life Sciences/P2 10 DBE/2014
NSC – Grade 12 Exemplar – Memorandum
Copyright reserved Please turn over
SECTION C
QUESTION 4
The development of a new species
• If a population splits into two populations.
• There is now no gene flow between the two populations.
• Since each population may be exposed to different environmental conditions,
• Natural selection occurs independently in each of the two populations
• such that the individuals of the two populations become very different from each other
• genotypically and phenotypically.
• Even if the two populations were to mix again,
• they will not be able to reproduce with each other, thus becoming different species (any 5)
The development of bipedalism
• The backward position of the foramen magnum on the skull,
• the narrow pelvis
• and the less-curved spine
• indicates that the ape-like beings were quadripedal (any 3)
• The forward position of the foramen magnum on the skull,
• the wider pelvis
• and the curved spine
• indicates that modern humans are bipedal (any 3)
Change in the diet from raw food to cooked food
• The large teeth, especially the canines
• as well as the large and long jaws
• which makes the skull prognathous
• as well as cranial/brow ridges associated with large muscles that operate the jaws
• indicate that the ape-like beings ate raw food that required a great amount of processing/tearing, biting and chewing. (any 3)
• The smaller teeth, including the canines
• as well as the smaller jaw size
• which makes the skull less prognathous
• as well as the absence of cranial/brow ridges due to the presence of smaller muscles for chewing
• indicate that modern humans rely on a diet of cooked food that does not require the same amount of processing/tearing, biting and chewing. (any 3)
Content:
Synthesis:
(5)
(6)
(6)
(17)
(3)
(20)
11. Life Sciences/P1 11 DBE/2014
NSC – Grade 12 Exemplar – Memorandum
Copyright reserved
ASSESSING THE PRESENTATION OF THE ESSAY
Relevance
Logical sequence
Comprehension
Only information regarding development of a new species, the development of bipedalism and change in diet is given (no irrelevant information).
Generally, the development of a new species, the development of bipedalism and change in diet are explained logically.
All three aspects of the question are described correctly.
TOTAL SECTION C:
20
GRAND TOTAL:
150