TMJC DNA Mut & Conseq Notes

Page 1 of 39 Tampines Meridian Junior College JC1 H2/9744 Biology 2023 Core Idea 2D | 2E 6. Genetics & Inheritance (III) – DNA Mutations & Their Consequences SYLLABUS OVERVIEW No. Overarching Idea Topics 1 Core Idea 1 The Cell and Biomolecules of Life Cell – The Basic Unit of Life 2 Biomolecules of Life and Cellular Transport 3 Core Idea 3 Energy and Equilibrium Transformation of Energy – Photosynthesis and Cellular Respiration 4 Core Idea 2 Genetics and Inheritance Genetics and Inheritance (I) – The Cell Cycle 5 Genetics and Inheritance (II) – DNA Replication and Gene Expression 6 Genetics and Inheritance (III) – DNA Mutations and their Consequences 7 Genetics and Inheritance (IV) – Molecular Techniques in DNA Analysis 8 Genetics and Inheritance (V) – Organization of Genome & Control of Gene Expression in Eukaryotes [Includes Core Idea 1D: Stem Cells] 9 Genetics and Inheritance (VI) – Organization and Inheritance of Viral Genomes 10 Genetics and Inheritance (VII) – Organization of Genome & Control of Gene Expression in Prokaryotes 11 Genetics and Inheritance (VIII) - Inheritance 12 Core Idea 3 Energy and Equilibrium Communication and Equilibrium in Multicellular Organisms 13 Core Idea 4 Biological Evolution Biological Evolution 14 Extension Topic A Infectious Diseases Immunity and Infectious Diseases 15 Extension Topic B Impact of Climate Change on Animals & Plants Climate Change – Causes and Impacts on Animals and Plants

Page 2 of 39 TOPIC SYNOPSIS An understanding of Genetics and Inheritance that would help make sense of the transition from molecular to organismal level. Genetics and Inheritance provides the molecular basis to the understanding of how variations in populations arise and this is important in the study of biological evolution. At the cellular level, expression of genes involves cellular structures such as the nucleus, endoplasmic r eticulum and ribosome. Many essential products of gene expression are enzymes involved in biochemical pathways which control physiological functions. As such, mutation of genes may give rise to dysfunctional proteins which in turn could result in diseases. Sickle cell anemia and cancer are raised as examples of a monogenic and a multi -genic disease respectively. The following questions should help you frame your learning: • How does the genetic make-up of an organism influence its appearance, behavior and survival? • How can we ensure continuity of human as a species? Mutation arises from imperfect replication of genetic information. Together with other biological processes, such mutations increase genetic variation. Based on the central dogma, a change in the sequence of DNA nucleotide, i.e. gene mutation, may affect the amino acid sequence in the polypeptide and hence the phenotype of the organism. Many mutations are detrimental to the individual since they affect the normal functioning of the gene product, e.g. genetic disease