§-Biology syllabus

TAS · TASC← Biology

Biology syllabus, dot point by dot point

Every dot point in the TAS Biology course document, in syllabus order, with a focused answer for each. Open any dot point for the answer, exam-style questions and links to related points.

Homeostasis (Module 2)

Section overview →

How do organisms keep their internal environment stable when conditions change?

Homeostasis involves a stimulus-response model in which a change in external or internal environmental conditions is detected and appropriate responses occur via negative feedback; in vertebrates, receptors and effectors are linked via a control centre by nervous or hormonal pathways, or both

How are nerve impulses generated, conducted and passed between neurons?

Neural pathways consist of cells that transport nerve impulses from sensory receptors to neurons and on to effectors: the passage of nerve impulses involves transmission of an action potential along a nerve axon, and synaptic transmission by neurotransmitters and signal transduction

How do hormones carry messages that change the activity of target cells?

Hormones alter the metabolism of target cells, tissues or organs by increasing or decreasing their activity; in animals, most hormones are produced in endocrine glands as a result of nervous or chemical stimulation and travel via the circulatory or lymph system to the target cells, tissues or organs

How do humans keep their body temperature within a narrow range?

Analyse thermoregulation in humans, including stimulus-response models, feedback loops and the associated messages and organ structures

How is blood glucose kept within a narrow range?

Analyse glucose regulation in humans, including stimulus-response models, feedback loops and the associated hormones (insulin and glucagon) and organ structures

How do the hypothalamus, ADH and the kidneys keep the body's water balance stable?

Analyse osmoregulation in humans, including stimulus-response models, feedback loops and the associated hormone (antidiuretic hormone) and organ structures, including kidney nephron function

How does water move from the roots to the leaves, and what affects the rate of transpiration?

Investigate the transport of water from the roots via xylem (involving root pressure, cohesion of water molecules and transpiration) to the leaves and the factors that influence the rate of transpiration (light intensity, temperature, wind and humidity)

How do desert animals and xerophytes maintain water balance in arid environments?

Understand the various mechanisms that animals and plants use to maintain water balance, involving structural features and behavioural and physiological responses, in an arid environment (desert animals and xerophytes)

Immunology (Module 3)

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What causes infectious disease, and how do pathogens spread between hosts?

Pathogens: biological pathogens include prions, viruses, bacteria, fungi, protists and parasites; infectious disease is caused by invasion of a pathogen, which can be transmitted from one host to another; adaptations of pathogens for entering cells and tissues and for transmission (direct contact, body fluids, contaminated food or water, vectors); the physical or chemical changes that stimulate immune responses; factors affecting the spread of disease

How does the innate immune system defend the body against any pathogen?

Immune response: vertebrates have innate (non-specific) and adaptive (specific) immune responses in three lines of defence; the first line is innate, non-specific physical and chemical barriers; the second line is innate, non-specific cellular, chemical and inflammatory responses involving phagocytes; cell specialisation (phagocytic cells) and the role of the cell membrane in endocytosis, including phagocytosis

How does the adaptive immune system target specific pathogens and remember them?

The third line of defence is adaptive and specific: persistent adaptive responses to specific antigens, including humoral immunity through the production of antibodies by B lymphocytes and cell-mediated immunity provided by T lymphocytes, with memory cells giving long-term immunity; the roles of antigen-presenting cells (dendritic cells and macrophages), mast cells, neutrophils, B lymphocytes, memory B cells, T lymphocytes, helper T cells, cytotoxic T cells, regulatory T cells and memory T cells

10 min read →

How can immunity be gained, and how does vaccination protect a whole population?

Vaccination and the concept of herd immunity: analyse the similarities and differences between passive immunity (for example antibodies acquired via the placenta or via antibody serum injection) and active immunity (acquired through the actions of the immune system as a result of natural exposure to a pathogen or through the use of vaccines)

Science inquiry skills (Module 1)

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How do you design, analyse and evaluate a biological investigation the way TASC markers expect?

Science inquiry skills: identify, research and construct questions, propose hypotheses and predict outcomes; design investigations (procedures, materials, data to collect, risk assessment, research ethics including animal ethics and the rights of living organisms); collect valid and reliable data; represent and analyse data (mean, median, range, trends and relationships; measurement error, accuracy, procedure and sample size as sources of uncertainty); evaluate processes, claims and conclusions

10 min read →

Biodiversity and ecosystems (Level 2 background)

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What is biodiversity and how do we measure it?

Define the levels of biodiversity and describe how species richness and evenness are measured.

What components make up an ecosystem and how do they interact?

Identify the biotic and abiotic components of ecosystems and explain how abiotic factors shape distribution.

How does energy move through an ecosystem?

Explain how energy flows through food chains and webs and why energy is lost at each trophic level.

What controls the size of a population and how do we measure it?

Explain the factors that change population size and describe methods used to estimate populations.

How and why do biologists classify living things?

Describe the system of biological classification and explain how organisms are named and grouped.

How do organisms interact with one another within a community?

Describe the types of interspecific relationships and explain their effects on the organisms involved.

Why are cells regarded as the basic units of all living things?

Explain cell theory and compare prokaryotic and eukaryotic cells.

How is matter recycled through ecosystems?

Describe the carbon, nitrogen, and water cycles and the role of organisms in moving matter.

Cells, enzymes and energy (Module 2)

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How do enzymes control the chemical reactions of life?

Enzymes: structure and function (globular protein, active site, denaturation); factors affecting rate of reaction (temperature, pH, enzyme concentration, substrate concentration, inhibitors, coenzymes and cofactors); competitive and non-competitive inhibitors; coenzymes and cofactors (general understanding only)

How is light energy captured and used to make glucose in the chloroplast?

Photosynthesis: the role of chloroplasts (thylakoids, stroma and grana); inputs and outputs as a balanced net chemical equation; factors affecting rate of reaction (temperature, carbon dioxide concentration and light intensity); a general understanding of the light-dependent and light-independent stages

How do cells release usable energy from glucose, with and without oxygen?

Respiration: the role of mitochondria in aerobic respiration; the main stages of anaerobic and aerobic respiration (glycolysis, the Krebs cycle and the electron transport chain); inputs and outputs as balanced net chemical equations; factors affecting rate of reaction (temperature, glucose concentration, oxygen concentration and pH)

How does the structure of each organelle suit its function?

Identify the main organelles of eukaryotic cells and relate their structure to function.

Why are cells small and why do large organisms have many cells?

Explain how the surface area to volume ratio limits cell size and exchange.

How does the cell membrane control what enters and leaves a cell?

Describe the structure of the cell membrane and explain the mechanisms of membrane transport.

DNA, genetics and cell division (Modules 2 and 3)

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How is DNA structured, and how is it copied accurately before a cell divides?

DNA structure and replication: DNA is a double-stranded molecule in the nucleus of eukaryotic cells; nucleotide composition and complementary base pairing (A-T, C-G); the process of DNA replication including the enzymes helicase, primase, DNA polymerase and ligase; the significance of semi-conservative replication; genome sequencing

How does the sequence of DNA direct the synthesis of proteins?

Protein synthesis: proteins are a diverse group of molecules, including enzymes; genes include coding (exons) and non-coding (introns and regulatory) components of DNA; transcription of a gene into messenger RNA in the nucleus; translation of mRNA into an amino acid sequence at the ribosome, using transfer RNA, codons and anticodons

How do bacteria switch genes on and off in response to their environment?

Gene expression and regulation: prokaryotic cells only, using the lac operon example; the phenotypic expression of genes depends on factors controlling transcription and translation, the products of other genes and the environment; differential gene expression controls cell differentiation

How do mutations arise, and how do they affect proteins?

Mutations: models of how mutations in genes and chromosomes result from errors in DNA (point and block mutations, including substitutions, deletions, additions and inversions), errors in cell division (types of chromosomal mutation) and damage by mutagens (physical, UV radiation, ionising radiation, heat and chemical); the impact of mutation on the final gene product, specifically protein

How do cells divide and how does meiosis create genetic variation?

Reproduction and cell division: chromosomes package DNA; all eukaryotic cells come from pre-existing cells through the cell cycle (G1, S, G2, M and C phases); the sub-phases of mitosis (prophase, metaphase, anaphase, telophase) and cytokinesis in animal cells; meiosis I and II, the role of homologous chromosomes in independent assortment and crossing over; random fertilisation and the significance of genetic variation

How are characteristics passed from parents to offspring and why do offspring vary?

Genetics: monohybrid crosses; use models such as Punnett squares to predict frequencies of genotypes and phenotypes for autosomal dominant or recessive, sex-linked dominant or recessive, incomplete dominance, codominance and multiple alleles (ABO blood groups only, with alleles i, IA and IB); use pedigree charts to analyse inheritance

How can a family pedigree be used to work out how a trait is inherited?

Use pedigree charts to describe and analyse the inheritance of genetic disorders and disease: identify and justify the likely mode of inheritance (dominant or recessive, autosomal or X-linked) and the likely genotypes of individuals

How do we manipulate and analyse DNA, and what are the implications?

Demonstrate and apply the use of enzymes to manipulate DNA, including polymerase to synthesise DNA, ligase to join DNA and endonucleases to cut DNA; investigate genome sequencing

Evolution (Module 3)

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How does natural selection lead to adaptation in populations?

Evolution: life on Earth has changed and diversified over time; mutation is the ultimate source of genetic variation; natural selection occurs when environmental selection pressures confer a selective advantage on a specific phenotype, enhancing its survival and reproduction

How and why do allele frequencies change within a population over time?

Concepts of natural selection, mutation, gene flow and genetic drift as causes of change in allele frequencies; investigate how populations with reduced genetic diversity, such as those affected by population bottlenecks, have an increased risk of extinction

How do new species arise from existing ones?

Analyse differing selection pressures between geographically isolated populations to demonstrate the process of speciation; represent and analyse the accumulation of micro-evolutionary changes over time and macro-evolutionary changes resulting in speciation

What evidence supports the theory of evolution by natural selection?

Describe and evaluate the lines of evidence that support evolution.