• explain the meaning of the term genetic code;
• explain how mutations can have beneficial, neutral or harmful effects on the way a protein functions;
• state that cyclic AMP activates proteins by altering their three-dimensional structure;
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• describe, with the aid of diagrams and photographs, the behaviour of chromosomes during meiosis, and the associated behaviour of the nuclear envelope, cell membrane and centrioles. (Names of the main stages are expected, but not the subdivisions of prophase);
• explain the terms allele, locus, phenotype, genotype, dominant, codominant and recessive;
• explain the terms linkage and crossing-over;
• explain how meiosis and fertilisation can lead to variation through the independent assortment of alleles;
• use genetic diagrams to solve problems involving sex linkage and codominance;
• describe the differences between continuous and discontinuous variation;
• explain the basis of continuous and discontinuous variation by reference to the number of genes which influence the variation;
• explain why variation is essential in selection
• explain, with examples, how environmental factors can act as stabilising or evolutionary forces of natural selection;
• explain how genetic drift can cause large changes in small populations;
• outline the differences between reproductive and non-reproductive cloning;
• describe how artificial clones of animals can be produced;
• discuss the advantages and disadvantages of cloning animals.
• explain why microorganisms are often used in biotechnological processes;
• describe, with the aid of diagrams, and explain the standard growth curve of a microorganism in a closed culture;
• describe how enzymes can be immobilised;
• outline the steps involved in sequencing the genome of an organism;
• outline how gene sequencing allows for genome-wide comparisons between individuals and between species;
• define the term recombinant DNA;
• describe how DNA probes can be used to identify fragments containing specific sequences;
• state other vectors into which fragments of DNA may be incorporated;
• explain how plasmids may be taken up by bacterial cells in order to produce a transgenic microorganism that can express a desired gene product;
• describe the advantage to microorganisms of the capacity to take up plasmid DNA from the environment;
• outline how genetic markers in plasmids can be used to identify the bacteria that have taken up a recombinant plasmid;
• outline the process involved in the genetic engineering of bacteria to produce human insulin;
• outline how animals can be genetically engineered for xenotransplantation;
• explain the term gene therapy;
• discuss the ethical concerns raised by the genetic manipulation of animals (including humans), plants and microorganisms.
• state that ecosystems are dynamic systems;
• define the terms biotic factor and abiotic factor
• explain how human activities can manipulate the flow of energy through ecosystems;
• describe one example of primary succession resulting in a climax community
• explain that conservation is a dynamic process involving management and reclamation;
• outline, with examples, the effects of human activities on the animal and plant populations in the Galapagos Islands.
• explain how plant responses to environmental changes are co-ordinated by hormones, with reference to responding to changes in light direction;
• discuss why animals need to respond to their environment;
• describe the role of the brain and nervous system in the co-ordination of muscular movement;
• describe how co-ordinated movement requires the action of skeletal muscles about joints, with reference to the movement of the elbow joint;
• explain, with the aid of diagrams and photographs, the sliding filament model of muscular contraction;
• outline the role of ATP in muscular contraction, and how the supply of ATP is maintained in muscles;
• state that responses to environmental stimuli in mammals are co-ordinated by nervous and endocrine systems;
• describe escape reflexes, taxes and kineses as examples of genetically-determined innate behaviours;
All the above are the specification points that have not yet come up.