HSC Biology — Module 1
Organelles — Flashcards & Quiz
Organelles are the specialised subcellular structures that carry out the metabolic work of eukaryotic cells, and HSC Biology Module 1 expects you to link each organelle's structure to its function. Examiners routinely test the endomembrane system (ER → Golgi → vesicles) and energy organelles (mitochondria, chloroplasts), so build a mental map of what each one makes, where it sits, and how it cooperates with its neighbours.
Key Points
- Nucleus houses the DNA, controls gene expression, and is bounded by a double membrane perforated by nuclear pores for mRNA export.
- Mitochondria are the site of aerobic respiration (ATP production); they have their own circular DNA and double membrane, the inner folded into cristae.
- Chloroplasts (plant cells only) host photosynthesis; thylakoid membranes (grana) contain chlorophyll and carry out the light-dependent reactions.
- Rough endoplasmic reticulum has ribosomes attached — synthesises secreted and membrane proteins; smooth ER handles lipid synthesis and detoxification.
- Golgi apparatus modifies, sorts, and packages proteins from the ER into vesicles for export or targeted delivery to organelles.
- Lysosomes (animal) contain hydrolytic enzymes for breakdown; plant vacuoles store water, salts, sugars, and maintain turgor pressure.
Common Mistakes to Avoid
- Confusing the nucleus (membrane-bound, DNA) with the nucleolus (no membrane, rRNA assembly).
- Claiming lysosomes are in plant cells — they're usually not; plants have a large central vacuole instead.
- Mixing up rough ER (protein synthesis) with smooth ER (lipid synthesis, detoxification).
- Treating mitochondria as "just ATP producers" — they also play roles in apoptosis and calcium signalling.
- Missing the double-membrane structure of mitochondria and chloroplasts (endosymbiotic origin).
Exam Strategy
HSC Module 1 organelle questions usually ask you to label a diagram and link structure to function. For each organelle: (1) describe the structure briefly, (2) state the function, (3) link a specific structural feature to how it enables the function (e.g. "inner mitochondrial cristae increase surface area for ATP synthesis"). Compare animal and plant cells when relevant.
Sample Flashcards
Q1: What is the function of the mitochondria?
Mitochondria are the site of aerobic cellular respiration, where glucose is broken down to produce ATP (energy) for the cell.
Q2: What is the function of the endoplasmic reticulum (ER)?
Rough ER (studded with ribosomes) synthesises and transports proteins. Smooth ER synthesises lipids and detoxifies chemicals.
Q3: What is the role of the Golgi apparatus?
The Golgi apparatus modifies, packages and sorts proteins and lipids received from the ER into vesicles for transport to their destination (secretion, membrane or lysosomes).
Q4: What are lysosomes and what do they do?
Lysosomes are membrane-bound vesicles containing hydrolytic (digestive) enzymes that break down waste materials, worn-out organelles and ingested pathogens.
Q5: What is the function of ribosomes?
Ribosomes are the site of protein synthesis (translation). They read mRNA and assemble amino acids into polypeptide chains.
Sample Quiz Questions
Q1: Mitochondria are found in both plant and animal cells.
Answer: TRUE
Both plant and animal cells carry out aerobic respiration and therefore contain mitochondria.
Q2: The rough endoplasmic reticulum synthesises lipids.
Answer: FALSE
The rough ER synthesises proteins (ribosomes on its surface translate mRNA). The smooth ER synthesises lipids.
Q3: The Golgi apparatus modifies, packages and sorts proteins for transport.
Answer: TRUE
The Golgi apparatus receives proteins from the ER, modifies them (e.g. adding carbohydrate chains), packages them into vesicles, and directs them to their destination.
Revision Tip
Organelle structure-function pairs are classic flashcard material — drill a Revizi deck with the 6-8 major organelles until recall is automatic.
Related Concepts
Last updated: March 2026 · 6 flashcards · 5 quiz questions