← Biology syllabus

SABiology

Topic 2: Cells as the Basis of Life

7 dot points across 7 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How does each organelle contribute to the life of the cell?

Describe the structure and function of the major eukaryotic cell organelles
The structure and roles of the nucleus, mitochondria, ER, Golgi, ribosomes, chloroplasts, vacuole and lysosomes, including how they cooperate to make and export proteins.
8 min answer →

How do cells release the energy stored in glucose?

Explain how aerobic and anaerobic respiration release energy from glucose to produce ATP
Cellular respiration releases energy from glucose to make ATP; aerobic respiration uses oxygen for a high ATP yield, while anaerobic respiration releases less and produces lactate or ethanol.
8 min answer →

How do plants convert light energy into chemical energy?

Explain how photosynthesis uses light energy to convert carbon dioxide and water into glucose
Photosynthesis in chloroplasts uses light to convert carbon dioxide and water into glucose and oxygen, via light-dependent and light-independent reactions, limited by light, CO2 and temperature.
8 min answer →

How do prokaryotic and eukaryotic cells differ?

Compare the structure and organisation of prokaryotic and eukaryotic cells
Prokaryotic cells are small with no nucleus or membrane-bound organelles; eukaryotic cells are larger with a true nucleus and membrane-bound organelles.
7 min answer →

Why are cells small, and how does size limit exchange with the environment?

Explain how the surface area to volume ratio limits cell size and affects the rate of exchange
As a cell grows, volume increases faster than surface area, so the surface area to volume ratio falls, limiting the rate of exchange and therefore cell size.
7 min answer →

How do cells grow, copy themselves and divide accurately?

Describe the stages of the cell cycle and mitosis and explain how they produce genetically identical cells
The cell cycle (interphase then mitosis and cytokinesis) produces two genetically identical daughter cells; checkpoints control it and failure of control can lead to cancer.
8 min answer →

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

Explain the fluid mosaic model and the mechanisms of passive and active transport across the membrane
The fluid mosaic membrane controls movement of substances by passive transport (diffusion, osmosis, facilitated diffusion) and active transport, which requires energy.
8 min answer →