Module 6: Genetic Change
9 dot points across 3 inquiry questions, in syllabus order. Each dot point has a focused answer, with exam-style questions and worked answers where available.
Inquiry Question 1: How does mutation introduce new alleles into a population?
Classifying mutations. Covers point mutations (substitution, insertion, deletion), silent vs missense vs nonsense, frameshift effects on reading frame, chromosomal mutations (deletion, duplication, inversion, translocation, non-disjunction), and the somatic vs germ-line distinction.
Mutagens. Physical mutagens (UV, X-rays, gamma rays), chemical mutagens (base analogues, alkylating agents, intercalators) and biological mutagens (viruses, transposons), with named examples and the molecular mechanism by which each damages DNA.
Pedigree analysis. How to identify autosomal recessive, autosomal dominant, X-linked recessive and X-linked dominant inheritance patterns from pedigree charts, with a worked haemophilia example and rules for spotting new mutations.
Sources of genetic variation. Meiotic shuffling (independent assortment, crossing over, random fertilisation), DNA replication fidelity, mutation as the ultimate source of new alleles, and the link to natural selection and evolution.
How mutations alter protein products. Coding versus non-coding regions, silent missense and nonsense substitutions, frameshift consequences, splice-site mutations, and a worked sickle cell example.
Inquiry Question 2: How do genetic techniques affect Earth's biodiversity?
Biotechnology uses. Agricultural (Bt cotton, golden rice), medical (recombinant insulin, gene therapy), industrial (rennet, biofuels) and forensic applications, with a balanced analysis of the social and ethical implications.
Biotechnology and biodiversity. The narrowing effect of monocultures and cloning, gene flow to wild relatives, herbicide and insecticide resistance, conservation applications (gene banks, de-extinction), and an evaluative judgement on net impact.
Inquiry Question 3: Does artificial manipulation of DNA have the potential to change populations forever?
Genetic technologies. Recombinant DNA (restriction enzymes, ligase, plasmid vectors), CRISPR-Cas9 mechanism, whole genome sequencing, gene therapy (somatic vs germline) and cloning of transgenic species, with named examples.
Future of genetic research and its potential impacts. Germline gene editing (heritable changes passed to offspring), gene drives, resistance evolution in pests and pathogens (Bt and antibiotic resistance), synthetic biology, xenotransplantation, and the regulatory and ethical questions they raise.