Module Organisation
D N
R
N
Suggested Teaching Sequences
Importance of proteins Genetic information flow that controls life phenomena
(DNA ÆDNA;
DNAÆRNAÆprotein;
proteinsÆlife phenomena) Relationship between
chromosomes, DNA and genes
DNA as the genetic material (Historical approach) From genes to proteins
Genetic basis of biodiversity, evolution, and genetic diseases Inheritance and
chromosomes
Applications of DNA technology Relationship between genes,
amino acids and proteins
Applications of DNA technology
Patterns of inheritance
Applications of DNA Mutations and variations Mutations and variations
Case studies on family history of genetic diseases / the use of DNA
fingerprinting in forensic science (e.g. parentage testing)
Inheritance and chromosomes
Patterns of inheritance
Chemical nature of genes
Sequence A Sequence B Sequ
C 8: From Genes to Life
Students should learn Suggested learning and teaching activities 8.1 Genetic information flow that
controls life phenomena
• The relationship between the structure of DNA and genetic information flow
• Transmission of genetic information to the next generation: replication of DNA
• Expression of genetic information to control life phenomena
− DNA molecules passing their information to mRNA molecules
− Decoding information in mRNA to produce protein molecules for various life processes
• Using the DNA spooling method to extract DNA from living materials (e.g.
onion and fish testes)
• Watch animations of the processes of genetic information flow
• Decode a DNA sequence
• Discuss the roles of proteins in our body: acting as enzymes, structural components and regulatory molecules
8.2 DNA as the genetic material
• Evidence which suggests DNA is the genetic material
• The double helix model for DNA molecules: evidence contributing to its construction; structural features enabling DNA to serve as a genetic carrier
• Deduction of Mendel’s Laws of Inheritance from findings on monohybrid and dihybrid inheritance
• Mitosis, meiosis, and chromosomal theory as the physical basis of Mendel’s Laws
• Information search on the experiments suggesting DNA is the genetic material and the discovery of the DNA structure
• Discuss how the work of physicists, chemists and biologists have contributed to our current knowledge on DNA
• Build a model of a double helix DNA molecule
• Read about Mendel’s work
• Carry out virtual experiments on monohybrid and dihybrid inheritance
• Use animations/films to show mitosis, meiosis and the coiling of DNA into chromosomes
• Use electron micrographs to show mitosis, meiosis, and chromosomes 8.3 Genetic basis of biodiversity,
evolution, and genetic diseases
• Factors contributing to variations between individuals within a species
• Genetic variations and the claim of evolution by natural selection
• Gene mutation and its possible effects (e.g. sickle-celled anemia)
• Chromosome mutation and its possible
• Using computer modelling to simulate evolution by natural selection
• Use the development of resistance in bacteria to certain antibiotics as an example to illustrate the claim of an evolutionary mechanism
• Activity to pair up chromosomes to
• Spontaneous and induced mutations Down syndrome
• Examine photomicrographs of chromosome mutation
• Discuss the precautionary measures in using X-rays in medical examinations 8.4 Applications of DNA technology
• Recombinant DNA technology: basic principle and its applications in gene cloning (e.g. production of insulin in E.
coli); gene therapy and production of genetically-modified crops
• DNA fingerprinting: applications in forensic science, parentage testing and diagnosis of genetic diseases
• Organism cloning
• The impact of the Human Genome Project on our society
• Carry out separation of digested DNA molecules by electrophoresis
• Using paper models to simulate the process of making recombinant DNA
• Use animations to illustrate the process of recombinant DNA technology
• Read about how the sheep Dolly was cloned
• Discuss the ethical, social and legal impact of biotechnology on society
• Discuss the limitations of the application of DNA fingerprinting in forensic science
Module highlights
In this module, students have opportunities to:
• appreciate that the cell is a highly organised entity in which nucleotides, DNA and chromosomes are at different levels of organisation
• recognise the specific order of the flow of genetic information from DNA to mRNA to protein
• appreciate that scientific theories evolve with new evidence (e.g. scientists came to refute protein as the genetic material when emerging experimental evidence pointed to DNA)
• appreciate the importance of imagination in theorising, as scientific theories do not emerge automatically from data and its analysis alone (e.g. Mendel suggesting the Laws of Inheritance well before the existence of genes was realised; Watson and Crick proposing the anti-parallel double helical structure of DNA)
• appreciate that the work of scientists in one field may contribute to development of ideas in another (e.g. Watson and Crick drew upon evidence worked out by scientists in different fields to build their hypothesis of the double helical structure of DNA)
• appreciate that the different sequencing of the bases of the nucleotides in the DNA molecules is the basis of biodiversity
• appreciate that scientific knowledge is generated from a systematic process: making hypotheses, verifying them through careful experimental design and analyses of experimental results, and drawing valid conclusions (e.g. Mendel’s deduction of Laws of Inheritance from carefully designed experiments)
• recognise that the constancy in chromosome number in a fertilised egg is maintained by meiosis in gamete formation; and that mutation may change the number of
• appreciate that though it can be induced or enhanced by mutagens, mutation occurs spontaneously in Nature
• develop the skills for making risk-benefit analysis in weighing the benefits of using nuclear radiation in medical diagnosis and therapy against the mutagenic effects of radiation to the body cells
• appreciate that science has its limitations and cannot always provide clear-cut answers in certain areas, such as the moral issues surrounding DNA technology
• realise that the direction of scientific research is affected by prevailing opinions in society and its culture (e.g. research using human embryos is allowed in some countries but not in others)
• develop a concern for issues relating to the applications of DNA technology in different fields
• realise the social impact of the swift advances in DNA technology which may affect one’s personal decisions
• appreciate the importance of the joint effort of scientists all over the world and peer review for the rapid achievements in the Human Genome Project