ACT SSC Biology — Unit 1
Cell Structure — Flashcards & Quiz
ACT SSC Biology Year 12 Unit 1 covers cell structure at the molecular and organellar level, including the comparison between prokaryotic and eukaryotic cells and the functions of the major organelles. You need to link each organelle's structure to its role and explain how they cooperate in the endomembrane system.
Key Points
- Prokaryotes (bacteria, archaea): no membrane-bound organelles, circular DNA in cytoplasm, 70S ribosomes, smaller and simpler.
- Eukaryotes (animals, plants, fungi, protists): membrane-bound organelles, linear DNA in nucleus, 80S ribosomes, more complex.
- Nucleus: houses DNA, controls gene expression, bounded by a double membrane with nuclear pores.
- Mitochondria: site of aerobic respiration; double membrane with inner cristae; own circular DNA (endosymbiotic origin).
- Endoplasmic reticulum: rough ER (with ribosomes) for protein synthesis; smooth ER for lipid synthesis and detoxification.
- Golgi apparatus: modifies, sorts and packages proteins into vesicles for export or targeted delivery.
Common Mistakes to Avoid
- Claiming prokaryotes have a nucleus — they don't; DNA is in the cytoplasm.
- Mixing up rough ER (protein) and smooth ER (lipid).
- Forgetting that mitochondria have their own DNA (endosymbiotic theory).
- Including lysosomes in plant cells — plants mostly use the central vacuole for similar functions.
- Confusing cell wall (plants, bacteria, fungi) with cell membrane (all cells).
Exam Strategy
BSSS Unit 1 cell structure questions ask you to label diagrams, compare cell types, or explain structure-function relationships. Method: (1) identify the cell type, (2) list organelles with their specific structural features, (3) link structure to function (e.g. inner mitochondrial cristae increase surface area for ATP synthesis), (4) compare with the other major cell type.
Sample Flashcards
Q1: What is the key structural difference between prokaryotic and eukaryotic cells?
Prokaryotic cells lack a membrane-bound nucleus and organelles; eukaryotic cells have a true nucleus enclosed by a nuclear envelope and membrane-bound organelles.
Q2: What is the function of the cell wall in plant cells?
The cell wall (made of cellulose) provides structural support, maintains cell shape, and prevents the cell from bursting when water enters by osmosis.
Sample Quiz Questions
Q1: Prokaryotic cells have a membrane-bound nucleus.
Answer: FALSE
Prokaryotic cells lack a membrane-bound nucleus. Their DNA is in a nucleoid region.
Q2: Both prokaryotic and eukaryotic cells contain ribosomes.
Answer: TRUE
Ribosomes are found in all cells — prokaryotic (70S) and eukaryotic (80S) — for protein synthesis.
Q3: The cell wall in plant cells prevents lysis in hypotonic solutions.
Answer: TRUE
The cellulose cell wall resists expansion, preventing lysis. The cell becomes turgid instead.
Revision Tip
Organelle structure-function pairs are classic flashcard content — drill a Revizi deck with the 6–8 major organelles until recall is automatic.
Last updated: March 2026 · 2 flashcards · 3 quiz questions