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EnglandBiology

Module 6: Genetics, evolution and ecosystems

6 dot points across 6 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How is gene expression controlled, and how do genes such as the lac operon and homeobox genes regulate cells and development?

6.1.1 Cellular control: the nature of gene mutations and their effects on proteins; the control of gene expression at the transcriptional level, including operons (the lac operon) and transcription factors; the role of homeobox (Hox) genes in body plan development; and the role of apoptosis (programmed cell death).
A focused answer to the OCR H420 6.1.1 dot point on cellular control. Covers gene mutations and their effects, the control of transcription by the lac operon and transcription factors, the role of homeobox (Hox) genes in body plan development, and apoptosis.
13 min answer →

How are plants and animals cloned, and how are microorganisms and immobilised enzymes used in biotechnology?

6.1.4 Cloning and biotechnology: natural and artificial cloning of plants (including micropropagation and tissue culture) and animals; the use of microorganisms in biotechnology and the conditions in an industrial fermenter; the principles and advantages of using immobilised enzymes; and the asepsis and growth curve of a microbial culture.
A focused answer to the OCR H420 6.1.4 dot point on cloning and biotechnology. Covers natural and artificial cloning of plants and animals, micropropagation and tissue culture, the use of microorganisms and the conditions in an industrial fermenter, immobilised enzymes, and the microbial growth curve.
13 min answer →

How does energy flow and nutrients cycle through ecosystems, and how can resources be used sustainably?

6.1.5 Ecosystems and sustainability: the flow of energy through ecosystems (gross and net primary productivity and trophic efficiency); the recycling of nutrients (the nitrogen and carbon cycles); primary and secondary succession; and the principles of managing ecosystems sustainably and conservation.
A focused answer to the OCR H420 6.1.5 dot point on ecosystems. Covers energy flow (gross and net primary productivity and trophic efficiency), the nitrogen and carbon cycles, primary and secondary succession, and the principles of sustainable management and conservation.
13 min answer →

How do we read, copy and engineer DNA, and how is DNA profiling used?

6.1.3 Manipulating genomes: the principles of DNA sequencing, the polymerase chain reaction (PCR) and gel electrophoresis; the use of restriction enzymes and ligase to produce recombinant DNA in genetic engineering; the principles of gene editing; and the use of DNA profiling.
A focused answer to the OCR H420 6.1.3 dot point on manipulating genomes. Covers DNA sequencing, the polymerase chain reaction and gel electrophoresis, restriction enzymes and ligase in genetic engineering, the principles of gene editing, and DNA profiling.
14 min answer →

How are characteristics inherited through monohybrid, dihybrid, codominant and sex-linked crosses, and how is the chi-squared test used?

6.1.2 Patterns of inheritance: monohybrid and dihybrid crosses; the inheritance of codominant and multiple alleles, sex linkage and epistasis; the use of genetic diagrams to predict phenotypic ratios; and the chi-squared test to compare observed and expected results.
A focused answer to the OCR H420 6.1.2 dot point on patterns of inheritance. Covers monohybrid and dihybrid crosses, codominance and multiple alleles, sex linkage and epistasis, genetic diagrams and phenotypic ratios, and the chi-squared test.
14 min answer →

How do allele frequencies change in populations, and how do new species form?

6.1.2 Populations and evolution: the meaning of a gene pool and allele frequency; the use of the Hardy-Weinberg principle to calculate allele and genotype frequencies; the factors that change allele frequencies (natural selection, genetic drift, the founder effect and migration); and the process of speciation (allopatric and sympatric).
A focused answer to the OCR H420 6.1.2 dot point on populations and evolution. Covers gene pools and allele frequency, the Hardy-Weinberg principle and its calculations, the factors that change allele frequencies including genetic drift and the founder effect, and allopatric and sympatric speciation.
13 min answer →