2016 H2 Application of Molecular and Cell Biology Notes dot

NANYANG JUNIOR COLLEGE H2 Biology Applications of Molecular and Cell Biology J2/2016 1 TOPIC P: APPLICATIONS OF MOLECULAR AND CELL BIOLOGY Learning Outcomes Application Topic 9: Application of Molecular and Cell Biology Candidates should be able to (a) Describe the unique features of zygotic stem cells, embryonic stem cells and blood stem cells; correctly using the terms:  Totipotency Zygotic stem cells which have ability to differentiate into any cell type to form whole organisms and so are also pluripotent and multipotent.  Pluripotency Embryonic stem cells which have ability to differentiat e into almost any cell type to form any organ or type of cell and so are not totipotent but are multipotent.  Multipotency Blood stem cells which have ability to differentiate into a limited range of cell type and so are not pluripotent or totipotent. (b) Explain the normal functions of stem cells in a living organism (e.g. embryonic stem cells and blood stem cells). (c) Describe:  two types of genetic diseases e.g. SCID (severe combined immunodeficiency) and cystic fibrosis;  the treatment of SCID and cystic fibrosis, using viral and non-viral gene delivery systems respectively. (Details of manipulation of genes and formation of vectors carrying genes are not required.) (d) Explain the factors that keep gene therapy from becoming an effective treatment for genetic diseases. (e) Discuss the social and ethical considerations for the use of gene therapy. (f) Discuss cloning in plants in terms of plant tissue culture techniques (Gene cloning in plants using Agrobacterium spp. and gene gun are not required.) (g) Explain the significance of genetic engineering in improving the quality and yield of crop plants and animals in solving t he demand for food in the world (e.g. Bt corn, golden rice, GM salmon). (h) Discuss the ethical and social implications of genetically modified crop plants and anima ls (e.g. Bt corn, golden rice, GM salmon). Use the knowledge gained in this section in new situations or to solve related problems.

NANYANG JUNIOR COLLEGE H2 Biology Applications of Molecular and Cell Biology J2/2016 2 References 1. Campbell N. A. and Reece J.B. (2005). Biology. Chapter 20: DNA Technology and Genomics. Seventh Edition. Pearson Education, Inc. 2. Snustad D. P., Simmons M. J., Jenkins J. B. (1997). Principles of Genetics. Chapter 20: Molecular Analysis of Genes and Gene Products. First Edition. John Wiley and Sons, Inc. 3. Plant Propagation by Tissue Culture 3rd Edition. (2008). Vol. 1. M. A. H. Edwin F. George, Geert-Jan De Klerk (Ed.) Volume 1. The Background 4. Websites related to cloning in plants, its significance, and social and ethical issues: (a) http://edugreen.teri.res.in/explore/bio/tissue.htm (b) http://www.ornl.gov/sci/techresources/Human_Genome/publicat/primer2001/7.shtml (c) http://bioethicsweb.ac.uk/browse/mesh/D030841.html (d) http://fpc.state.gov/fpc/6176.htm (e) http://www.cimmyt.org/abc/10-faqaboutgmos/htm/10-faqaboutgmos.htm 5. Websites related to gene therapy, and its social and ethical issues: (a) http://www.scid.net/about.htm (b) http://www.ygyh.org/cf/whatisit.htm (c) http://www.ornl.gov/sci/techresources/Human_Genome/medicine/genetherapy.shtml#fa ctors (d) http://www.ornl.gov/sci/techresources/Human_Genome/publicat/primer2001/6.shtml (e) http://www.ornl.gov/sci/techresources/Human_Genome/publicat/primer2001/8.shtml 6. Websites related to stem cells (a) http://www.exploratorium.edu/imaging_station/gallery.php?Category=stemcells (b) http://stemcells.nih.gov/info/basics/basics1.asp Content Outline 1. Introduction 2. Techniques (a) Plant Tissue Culture (b) Genetic engineering in Plants (c) Genetic engineering in Animals 3. Genetically Modified Organisms (a) Importance and Benefits (in improving quality and yield) (b) Social, Environmental and Ethical Issues of Genetically Modified Organisms 4. Stem Cell (a) Features of Stem Cells (b) Functions of Stem Cells in Living Organisms 5. Gene therapy (a) Techniques (b) Importance and Benefits in treatment of SCID and CF (c) Limitations of Gene therapy (d) Social and Ethical Issues

NANYANG JUNIOR COLLEGE H2 Biology Applications of Molecular and Cell Biology J2/2016 3 1. Introduction In the previous topic, we have covered how recombinant DNA can be made using various molecular techniques. In this topic, we will focus on the application of genetic engineering technologies to plants and animals. Some of these applications include:  Introduction or enhancement of d esirable traits in agronomic plants and domestic animals  Production of valuable products by genetically modified plants and animals  Investigation of basic biological processes such as gene expression in genetically modified organisms  Gene therapy and stem cell research. A genetically modified organism is an organism that has its genetic material altered through the use of recombinant DNA technology . This technology involves the combination of DNA molecules from different sources into one molecule to create a new set of genes. A transgenic organism, a specific type of genetically modified organism, is an organism that has its genetic material altered by the insertion of a transgene, which confers desirable traits, through the use of recombinant DNA technology. The transgene is a DNA molecule obtained from different species, and can be inherited to subsequent generations. DNA is taken up by the cells and then inserts itself into one or more of the recipient’s chromosomes; it is then inherited like any othe r gene. From a transgenic cell, a multicellular transgenic organism can be produced; all of whose cells contain the transgene.

NANYANG JUNIOR COLLEGE H2 Biology Applications of Molecular and Cell Biology J2/2016 4 2. Techniques Plants have been genetically manipulated by plant breeders for decades. Today, plant breeders can directly modify the DNA of organisms and introduce genes from other species to plant or animal genomes by recombinant DNA techniques. To date, scientists have successfully manipulated various plants and animals to pos sess phenotypically benef icial characteristics. (a) Plant Tissue Culture Plant tissue culture is the technique of growing pieces of plant cells, tissues or organs (explants) isolated from the source plant , under controlled conditions on sterile artificial medium. This method of growing plants is called in vitro growth (outside the organism) as opposed to in vivo (within the organism). Micropropagation is used specifically to refer to the use of tissue culture technique to propagate plants. The objective of micropropagation is to create clones, via asexual propagation. This is especially useful in regeneration of genetically engineered plants and genotype modification, in which many exact copies are needed. (i) Plant Tissue Culture (Micropropagation) Procedure Preparation of the culture medium The plant tissue culture media supply the nutrients necessary for growth. However, the components of the nutrient medium may differ dependi ng on factors such as the species of plant to be cultured, type of organ cultured and stages of culture. The most common medium used is Murashige and Skoog medium (MS medium).  Inorganic mineral elements, which include macronutrients and micronutrients  Macronutrients: Salts of nitrogen, potassium, magnesium, calcium, phosphorus, sulphur  Micronutrients: Salts of iron, zinc, manganese etc. This is needed in much lower concentrations than macronutrients.  Organic compounds:  Sugar (e.g. sucrose; as a carbon or energy source)  Vitamins (cofactor for metabolic functions)  Amino acids  Plant growth regulators: E.g. Auxins and Cytokinins. Auxin and Cytokinin ratio will affect the morphogenesis of cultured tissues  High cytokinin to auxin ratio (cytokinin >