Biology

Rationale/Aims

Biology is the study of the fascinating diversity of life as it has evolved and as it interacts and functions. Investigation of biological systems and their interactions, from cellular processes to ecosystem dynamics, has led to biological knowledge and understanding that enable us to explore and explain everyday observations, find solutions to biological issues, and understand the processes of biological continuity and change over time.

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Structure of Biology

Biology is the study of the fascinating diversity of life as it has evolved and as it interacts and functions. Investigation of biological systems and their interactions, from cellular processes to ecosystem dynamics, has led to biological knowledge and understanding that enable us to explore and explain everyday observations, find solutions to biological issues, and understand the processes of biological continuity and change over time.

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Links to Foundation to Year 10

The senior secondary Biology curriculum continues to develop student understanding and skills from across the three strands of the F-10 Australian Curriculum: Science. In the Science Understanding strand, the Biology curriculum draws on knowledge and understanding from across the four sub-strands of Biological, Physical, Chemical, and Earth and Space sciences.

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Representation of Cross-curriculum Priorities

While the significance of the cross-curriculum priorities for Biology varies, there are opportunities for teachers to select contexts that incorporate the key concepts from each priority.

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Achievement standards

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Unit 3: Heredity and continuity of life

Unit 3: Heredity and continuity of life Description

Heredity is an important biological principle as it explains why offspring (cells or organisms) resemble their parent cell or organism. Organisms require cellular division and differentiation for growth, development, repair and sexual reproduction. In this unit, students investigate the biochemical and cellular systems and processes involved in the transmission of genetic material to the next generation of cells and to offspring. They consider different patterns of inheritance by analysing the possible genotypes and phenotypes of offspring. Students link their observations to explanatory models that describe patterns of inheritance, and explore how the use of predictive models of inheritance enables decision making.

Students investigate the genetic basis for the theory of evolution by natural selection through constructing, using and evaluating explanatory and predictive models for gene pool diversity of populations. They explore genetic variation in gene pools, selection pressures and isolation effects in order to explain speciation and extinction events and to make predictions about future changes to populations.

Through the investigation of appropriate contexts, students explore the ways in which models and theories related to heredity and population genetics, and associated technologies, have developed over time and through interactions with social, cultural, economic and ethical considerations. They investigate the ways in which science contributes to contemporary debate about local, regional and international issues, including evaluation of risk and action for sustainability, and recognise the limitations of science to provide definitive answers in different contexts.

Students use science inquiry skills to design and conduct investigations into how different factors affect cellular processes and gene pools; they construct and use models to analyse the data gathered; and they continue to develop their skills in constructing plausible predictions and valid, reliable conclusions.


Unit 3: Heredity and continuity of life Learning Outcomes

By the end of this unit, students:

  • understand the cellular processes and mechanisms that ensure the continuity of life, and how these processes contribute to unity and diversity within a species
  • understand the processes and mechanisms that explain how life on Earth has persisted, changed and diversified over the last 3.5 billion years
  • understand how models and theories have developed over time; and the ways in which biological knowledge interacts with social, economic, cultural and ethical considerations in a range of contexts
  • use science inquiry skills to design, conduct, evaluate and communicate investigations into heredity, gene technology applications, and population gene pool changes
  • evaluate with reference to empirical evidence, claims about heredity processes, gene technology, and population gene pool processes, and justify evaluations
  • communicate biological understanding using qualitative and quantitative representations in appropriate modes and genres.

Unit 3: Heredity and continuity of life Content Descriptions

Science Inquiry Skills (Biology Unit 3)

Identify, research and construct questions for investigation; propose hypotheses; and predict possible outcomes (ACSBL061)

Design investigations, including the procedure/s to be followed, the materials required, and the type and amount of primary and/or secondary data to be collected; conduct risk assessments; and consider research ethics, including animal ethics (ACSBL062)

Conduct investigations, including the use of probabilities to predict inheritance patterns, real or virtual gel electrophoresis, and population simulations to predict population changes, safely, competently and methodically for the collection of valid and reliable data (ACSBL063)

Represent data in meaningful and useful ways, including the use of mean, median, range and probability; organise and analyse data to identify trends, patterns and relationships; discuss the ways in which measurement error, instrumental accuracy, the nature of the procedure and the sample size may influence uncertainty and limitations in data; and select, synthesise and use evidence to make and justify conclusions (ACSBL064)

Interpret a range of scientific and media texts, and evaluate models, processes, claims and conclusions by considering the quality of available evidence, including interpreting confidence intervals in secondary data; and use reasoning to construct scientific arguments (ACSBL065)

Select, construct and use appropriate representations, including models of DNA replication, transcription and translation, Punnett squares and probability models of expression of a specific gene in a population, to communicate conceptual understanding, solve problems and make predictions (ACSBL066)

Communicate to specific audiences and for specific purposes using appropriate language, nomenclature, genres and modes, including scientific reports (ACSBL067)

Science as a Human Endeavour (Units 3 & 4)

ICT and other technologies have dramatically increased the size, accuracy and geographic and temporal scope of data sets with which scientists work (ACSBL068)

Models and theories are contested and refined or replaced when new evidence challenges them, or when a new model or theory has greater explanatory power (ACSBL069)

The acceptance of scientific knowledge can be influenced by the social, economic and cultural context in which it is considered (ACSBL070)

People can use scientific knowledge to inform the monitoring, assessment and evaluation of risk (ACSBL071)

Science can be limited in its ability to provide definitive answers to public debate; there may be insufficient reliable data available, or interpretation of the data may be open to question (ACSBL072)

International collaboration is often required when investing in large-scale science projects or addressing issues for the Asia-Pacific region (ACSBL073)

Scientific knowledge can be used to develop and evaluate projected economic, social and environmental impacts and to design action for sustainability (ACSBL074)

Science Understanding

DNA, genes and the continuity of life

Examples in context

Support materials only that illustrate some possible contexts for exploring Science as a Human Endeavour concepts in relation to Science Understanding content.

Bioinformatics

Bioinformatics involves the construction, maintenance and use of databases to analyse the relationships in biological data, such as amino acid sequences or nucleotide sequences (ACSBL068). DNA and protein sequences can be mapped and analysed to compare genes within a species or between different species. One example of a bioinformatics project is the Human Genome Project, an international, collaborative research project which resulted in the publication of the full sequence of the human genome in 2003 (ACSBL073). The project was completed ahead of schedule, largely as a result of widespread international cooperation and advances in genomics and computing. The databases associated with the project are freely available via the internet, and this data is used extensively by the international scientific community.

A $1000 genome

A number of companies have announced that individuals will soon be able to access full genome sequencing for roughly $1000, enabling many more people to identify whether they have gene variants associated with genetic disease (ACSBL071). One potential application of this technology is the sequencing of all babies at birth, in order to enable doctors to identify genetic conditions and structure individualised healthcare, dietary and exercise regimes that will lead to better health. However there is significant concern about the risks in making this data so readily available, and the privacy issues regarding ownership and availability of sequences. Many groups are calling for safeguards to be implemented before whole genome sequencing becomes widespread, including legislation to protect personal privacy, regardless of how the sample was obtained (ACSBL070).

Genetically modified organisms

Genetic engineering to insert genes responsible for specific traits into plant and animal DNA is seen by some scientists as the next wave of advancement in agriculture, with the potential to increase crop yields and provide ways to grow crops on degraded lands (ACSBL074). A wide range of transgenic crops is currently on the market, some having been engineered to resist pesticides, insects and disease. Work is also underway on transgenic animals with engineered traits such as faster growth and the ability to produce pharmaceuticals. Critics fear that genetically engineered products are being rushed to market before their effects are fully understood. Concerns include possible health risks to consumers and the long term ecological impact of releasing engineered organisms into the environment, including the effects on non-target organisms, a speeding of the evolution of pesticide-resistant pest species, and the possibility of gene flow from crop species to weed species resulting in the emergence of ‘super weeds’ (ACSBL072).

Continuity of life requires the replication of genetic material and its transfer to the next generation through processes including binary fission, mitosis, meiosis and fertilisation (ACSBL075)

DNA is a helical double-stranded molecule that occurs bound to proteins in chromosomes in the nucleus, and as unbound circular DNA in the cytosol of prokaryotes and in the mitochondria and chloroplasts of eukaryotic cells (ACSBL076)

The structural properties of the DNA molecule, including nucleotide composition and pairing and the weak bonds between strands of DNA, allow for replication (ACSBL077)

Genes include ‘coding’ and ‘non-coding’ DNA, and many genes contain information for protein production (ACSBL078)

Protein synthesis involves transcription of a gene into messenger RNA in the nucleus, and translation into an amino acid sequence at the ribosome (ACSBL079)

Proteins, including enzymes, are essential to cell structure and functioning (ACSBL080)

The phenotypic expression of genes depends on factors controlling transcription and translation during protein synthesis, the products of other genes, and the environment (ACSBL081)

Mutations in genes and chromosomes can result from errors in DNA replication or cell division, or from damage by physical or chemical factors in the environment (ACSBL082)

Differential gene expression controls cell differentiation for tissue formation, as well as the structural changes that occur during growth (ACSBL083)

Variations in the genotype of offspring arise as a result of the processes of meiosis and fertilisation, as well as a result of mutations (ACSBL084)

Frequencies of genotypes and phenotypes of offspring can be predicted using probability models, including Punnett squares, and by taking into consideration patterns of inheritance, including the effects of dominant, autosomal and sex-linked alleles and multiple alleles, and polygenic inheritance (ACSBL085)

DNA sequencing enables mapping of species genomes; DNA profiling identifies the unique genetic makeup of individuals (ACSBL086)

Biotechnology can involve the use of bacterial enzymes, plasmids as vectors, and techniques including gel electrophoresis, bacterial transformations and PCR (ACSBL087)

Continuity of life on Earth

Examples in context

Support materials only that illustrate some possible contexts for exploring Science as a Human Endeavour concepts in relation to Science Understanding content.

Evidence for evolution

Darwin proposed the theory of evolution by natural selection to refute Lamarck’s theory. He provided evidence for descent with modification (branching evolution) based on patterns in variation of domesticated and wild species, and patterns of species distributions in time and space (ACSBL069). Contemporary evidence for evolution comes from five main lines of evidence: paleontology, biogeography, developmental biology, morphology and genetics. Technological developments in the fields of comparative genomics, comparative biochemistry and bioinformatics have enabled identification of further evidence for evolutionary relationships (ACSBL068).

Human evolution – are we still evolving?

Theoretical models of natural selection do not account for culture and technology, which can alter selection pressures so that it is not necessarily the ‘fittest’ that survive to reproduce. This has caused some to ask whether human evolution is still occurring, particularly in Western societies post the significant cultural events of agriculture, the Industrial Revolution, modern medicine and mass transportation. However, new results from projects such as the 1000 Genomes Project indicate that the rapid increase in the human population (from roughly five million at the end of the last Ice Age to more than seven billion today) has generated an enormous amount of variation in the species (ACSBL068). Other localised studies point to fertility-related natural selection (ACSBL069).

Sustainable population size and reserve area

The notion of minimum reserve size to maintain ecological processes is an important focus of conservation planning, and includes consideration of biogeography and population dynamics. Estimating minimum reserve size for a target conservation species can involve the calculation of minimum viable population and consideration of the area required for each individual in that population, given species preferences for particular habitat and social dynamics within the population (ACSBL074). However, determination of reserve size must also consider the needs and attitudes of other stakeholders, including cultural and economic values of indigenous peoples, recreational and aesthetic values of the public, the capacity to protect, monitor and manage the reserve, and other factors (ACSBL070). An alternative to single large reserves may be a number of smaller reserves that are connected by ‘green corridors’ that enable fauna to migrate.

Life has existed on Earth for approximately 3.5 billion years and has changed and diversified over time (ACSBL088)

Comparative genomics provides evidence for the theory of evolution (ACSBL089)

Natural selection occurs when selection pressures in the environment confer a selective advantage on a specific phenotype to enhance its survival and reproduction; this results in changes in allele frequency in the gene pool of a population (ACSBL090)

In additional to environmental selection pressures, mutation, gene flow and genetic drift can contribute to changes in allele frequency in a population gene pool and results in micro-evolutionary change (ACSBL091)

Mutation is the ultimate source of genetic variation as it introduces new alleles into a population (ACSBL092)

Speciation and macro-evolutionary changes result from an accumulation of micro-evolutionary changes over time (ACSBL093)

Differing selection pressures between geographically isolated populations may lead to allopatric speciation (ACSBL094)

Populations with reduced genetic diversity face increased risk of extinction (ACSBL095)