Recognise that biodiversity includes the diversity of species and ecosystems.
Determine diversity of species using measures such as species richness, evenness, percentage cover, percentage frequency, and Simpson’s diversity index.
Use species diversity indices, species interactions (predation, competition, symbiosis, disease), and abiotic factors (climate, substrate, size/depth of area) to compare ecosystems across spatial and temporal scales.
Explain how environmental factors limit the distribution and abundance of species in an ecosystem.
Mandatory Practical:
Determine species diversity of a group of organisms based on a given index.
Classification Processes
Recognise that biological classification can be hierarchical and based on different levels of similarity of physical features, methods of reproduction, and molecular sequences.
Describe the classification systems for similarity of physical features (the Linnaean system), methods of reproduction (asexual, sexual — K and r selection), molecular sequences (molecular phylogeny — also called cladistics).
Define the term clade.
Recall that common assumptions of cladistics include common ancestry, bifurcation, and physical change.
Interpret cladograms to infer the evolutionary relatedness between groups of organisms.
Analyse data from molecular sequences to infer species evolutionary relatedness.
Recognise the need for multiple definitions of species.
Identify one example of an interspecific hybrid that does not produce fertile offspring (e.g. mule, Equus mulus).
Explain the classification of organisms according to the following species interactions:
Predation
Competition
Symbiosis
Disease
Understand that ecosystems are composed of varied habitats (microhabitat to ecoregion).
Interpret data to classify and name an ecosystem.
Explain how the process of classifying ecosystems is an important step towards effective ecosystem management (consider old-growth forests, productive soils, and coral reefs).
Describe the process of stratified sampling in terms of:
Choice of ecological surveying technique (quadrats, transects).
Minimising bias (size and number of samples, random-number generators, counting criteria, calibrating equipment and noting associated precision).
Methods of data presentation and analysis.
Unit 3 Topic 2: Ecosystem Dynamics
Functioning Ecosystems
Sequence and explain the transfer and transformation of solar energy into biomass as it flows through biotic components of an ecosystem, including:
Converting light to chemical energy.
Producing biomass and interacting with components of the carbon cycle.
Analyse and calculate energy transfer (food chains, webs, and pyramids) and transformations within ecosystems, including:
Loss of energy through radiation, reflection, and absorption.
Efficiencies of energy transfer from one trophic level to another.
Biomass.
Construct and analyse simple energy-flow diagrams illustrating the movement of energy through ecosystems, including the productivity (gross and net) of the various trophic levels.
Describe the transfer and transformation of matter as it cycles through ecosystems (water, carbon, and nitrogen).
Define ecological niche in terms of habitat, feeding relationships, and interactions with other species.
Understand the competitive exclusion principle.
Analyse data to identify species (including microorganisms) or populations occupying an ecological niche.
Define keystone species and understand the critical role they play in maintaining the structure of a community.
Analyse data (from an Australian ecosystem) to identify a keystone species and predict the outcomes of removing the species from an ecosystem.
Population Ecology
Define the term carrying capacity.
Explain why the carrying capacity of a population is determined by limiting factors (biotic and abiotic).
Calculate population growth rate and change (using birth, death, immigration, and emigration data).
Use the Lincoln Index to estimate population size from secondary or primary data.
Analyse population growth data to determine the mode of population growth:
Exponential growth (J-curve).
Logistic growth (S-curve).
Discuss the effect of changes within population-limiting factors on the carrying capacity of the ecosystem.
Changing Ecosystems
Explain the concept of ecological succession (refer to pioneer and climax communities and seres).
Differentiate between the two main modes of succession:
Primary succession.
Secondary succession.
Identify the features of pioneer species that make them effective colonisers:
Ability to fixate nitrogen.
Tolerance to extreme conditions.
Rapid germination of seeds.
Ability to photosynthesise.
Analyse data from the fossil record to observe past ecosystems and changes in biotic and abiotic components.
Analyse ecological data to predict temporal and spatial successional changes.
Predict the impact of human activity on:
The reduction of biodiversity.
The magnitude, duration, and speed of ecosystem change.
Mandatory practical:
Select and appraise an ecological surveying technique to analyse species diversity between two spatially variant ecosystems of the same classification (e.g., a disturbed and undisturbed dry sclerophyll forest).
Unit 4 Topic 1: DNA, Genes, and the Continuity of Life
DNA Structure and Replication
Understand that deoxyribonucleic acid (DNA) is a double-stranded molecule that:
Occurs bound to proteins (histones) in chromosomes in the nucleus.
Occurs as unbound circular DNA in the cytosol of prokaryotes.
Is present in the mitochondria and chloroplasts of eukaryotic cells.
Recall the structure of DNA, including:
Nucleotide composition.
Complementary base pairing.
Weak, base-specific hydrogen bonds between DNA strands.
Explain the role of:
Helicase: unwinding the double helix and separation of the strands.
DNA polymerase: formation of the new complementary strands, with reference to the direction of replication.
Cellular Replication and Variation
Within the process of meiosis I and II:
Recognise the role of homologous chromosomes.
Describe the processes of crossing over and recombination and demonstrate how they contribute to genetic variation.
Compare and contrast the process of spermatogenesis and oogenesis (with reference to haploid and diploid cells).
Demonstrate how the process of independent assortment and random fertilisation alter the variations in the genotype of offspring.
Gene Expression
Define the terms:
Genome.
Gene.
Understand that genes include:
‘Coding’ DNA (exons).
‘Noncoding’ DNA, which includes:
Functional RNA (e.g., tRNA).
Centromeres.
Telomeres.
Introns.
Recognise that many functions of ‘noncoding’ DNA are yet to be determined.
Explain the process of protein synthesis in terms of:
Transcription of a gene into messenger RNA (mRNA) in the nucleus.
Translation of mRNA into an amino acid sequence at the ribosome (refer to transfer RNA, codons, and anticodons).
Recognise that:
The purpose of gene expression is to synthesise a functional gene product (protein or functional RNA).
The process can be regulated and is used by all known life.
Identify factors that regulate the phenotypic expression of genes:
During transcription and translation (proteins that bind to specific DNA sequences).
Through the products of other genes.
Via environmental exposure (consider the twin methodology in epigenetic studies).
Recognise that differential gene expression, controlled by transcription factors, regulates cell differentiation for tissue formation and morphology.
Recall an example of a transcription factor gene that regulates:
Morphology (HOX transcription factor family).
Cell differentiation (sex-determining region Y).
Mutations
Identify how mutations in genes and chromosomes can result from errors in:
Describe how inherited mutations can alter the variations in the genotype of offspring.
Inheritance
Predict frequencies of genotypes and phenotypes using data from probability models:
Including frequency histograms and Punnett squares.
Taking into consideration patterns of inheritance for the following types of alleles:
Autosomal dominant.
Sex-linked.
Multiple alleles.
Define polygenic inheritance and predict frequencies of genotypes and phenotypes using three of the possible alleles.
Biotechnology
Describe the process of making recombinant DNA:
Isolation of DNA.
Cutting of DNA (using restriction enzymes).
Insertion of DNA fragment (using plasmid vector).
Joining of DNA (using DNA ligase).
Amplification of recombinant DNA (through bacterial transformation).
Recognise the applications of:
DNA sequencing to map species' genomes.
DNA profiling to identify unique genetic information.
Explain the purpose of:
Polymerase chain reaction (PCR).
Gel electrophoresis.
Appraise data from the outcome of a current genetic biotechnology technique to determine its success rate.
Unit 4 Topic 2: Continuity of Life on Earth
Evolution
Define the terms:
Evolution.
Microevolution.
Macroevolution.
Determine episodes of evolutionary radiation and mass extinctions from an evolutionary timescale of life on Earth (approximately 3.5 billion years).
Interpret data (i.e., degree of DNA similarity) to reveal phylogenetic relationships, with an understanding that:
Comparative genomics involves the comparison of genomic features.
This provides evidence for the theory of evolution.
Natural Selection and Microevolution
Recognise natural selection occurs when the pressures of environmental selection confer a selective advantage on a specific phenotype to enhance its survival (viability) and reproduction (fecundity).
Identify that the selection of allele frequency in a gene pool can be positive or negative.
Interpret data and describe the three main types of phenotypic selection:
Stabilising selection.
Directional selection.
Disruptive selection.
Explain microevolutionary change through the main processes of:
Mutation.
Gene flow.
Genetic drift.
Mandatory practical: Analyse genotypic changes for a selective pressure in a gene pool (modelling can be based on laboratory work or computer simulation).
Speciation and Macroevolution
Recall that speciation and macroevolutionary changes result from an accumulation of microevolutionary changes over time.
Identify that diversification between species can follow one of four patterns:
Divergent.
Convergent.
Parallel.
Coevolution.
Describe the modes of speciation:
Allopatric.
Sympatric.
Parapatric.
Understand that the different mechanisms of isolation — geographic (including environmental disasters, habitat fragmentation), reproductive, spatial, and temporal — influence gene flow.
Explain how populations with reduced genetic diversity (i.e., those affected by population bottlenecks) face an increased risk of extinction.
Interpret gene flow and allele frequency data from different populations in order to determine speciation.
