Unit 1: Cells and multicellular organisms
8 dot points across 2 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.
Topic 1: Cells as the basis of life
- Describe the structure and function of cellular components, including the plasma membrane (fluid mosaic model), cytosol, nucleus, mitochondria, chloroplasts, endoplasmic reticulum, Golgi apparatus, lysosomes, vesicles, vacuoles, cell wall and cytoskeleton
A focused answer to the QCE Biology Unit 1 dot point on cellular components. Describes the plasma membrane using the fluid mosaic model, then names the structure and function of each membrane-bound organelle (nucleus, mitochondrion, chloroplast, ER, Golgi, lysosome, vesicle, vacuole) plus the cytoskeleton and cell wall.
9 min answer → - Describe the cell theory and distinguish between prokaryotic and eukaryotic cells, recalling that prokaryotes include bacteria and archaea
A focused answer to the QCE Biology Unit 1 dot point on cell theory and cell types. States the three postulates of cell theory, contrasts prokaryotic and eukaryotic cells across membrane-bound organelles, genetic material, ribosomes and size, and groups bacteria and archaea as the two prokaryotic domains.
7 min answer → - Explain the role of enzymes as biological catalysts and the effect of temperature, pH, substrate concentration, enzyme concentration and inhibitors on enzyme activity
A focused answer to the QCE Biology Unit 1 dot point on enzymes. Defines enzymes and the active site, applies the induced-fit model, and predicts the effect of temperature, pH, substrate and enzyme concentration and inhibitors (competitive and non-competitive) on reaction rate.
8 min answer → - Describe passive and active transport processes that move materials across cell membranes, including diffusion, osmosis (hypertonic, hypotonic, isotonic solutions), facilitated diffusion, protein pumps, endocytosis (phagocytosis and pinocytosis) and exocytosis
A focused answer to the QCE Biology Unit 1 dot point on membrane transport. Defines diffusion, osmosis (with tonicity), facilitated diffusion and active transport including protein pumps, endocytosis and exocytosis, and predicts the direction and energy requirements for each.
9 min answer → - Summarise the inputs, outputs and locations of photosynthesis and of aerobic and anaerobic cellular respiration
A focused answer to the QCE Biology Unit 1 dot point on photosynthesis and respiration. Writes the balanced word and chemical equations for photosynthesis and aerobic respiration, locates each in chloroplasts and mitochondria, and compares anaerobic respiration in animals (lactic acid) and yeast (ethanol).
8 min answer → - Explain how the surface area to volume ratio limits cell size and influences the structure of cells and exchange surfaces
A focused answer to the QCE Biology Unit 1 dot point on surface area to volume ratio. Calculates SA:V for simple cubes, shows why it falls as size rises, and links the ratio to limits on diffusion, the typical size range of cells and the structural adaptations of exchange surfaces.
7 min answer →
Topic 2: Multicellular organisms
- Describe gas exchange and internal transport in plants (stomata, xylem, phloem, transpiration and the cohesion-tension theory) and animals (alveoli, gills, open and closed circulatory systems, the human circulatory system)
A focused answer to the QCE Biology Unit 1 dot point on exchange and transport. Describes gas exchange surfaces in plants (stomata) and animals (alveoli, gills), the cohesion-tension theory of transpiration, the phloem translocation pathway and the differences between open and closed circulatory systems including the human four-chambered heart.
10 min answer → - Describe the hierarchical organisation of multicellular organisms (specialised cells, tissues, organs and organ systems) and compare totipotent, pluripotent and multipotent stem cells
A focused answer to the QCE Biology Unit 1 dot point on multicellular hierarchy and stem cells. Lays out the cell to tissue to organ to organ-system progression with named examples and contrasts totipotent, pluripotent and multipotent stem cells across potency and source.
8 min answer →