Q BankQuestion BankDocsDocuments

A2.2.5—Prokaryote cell structure

Prokaryotic cells organize metabolism and heredity without a nucleus, using a membrane-bounded cytoplasm containing 70S ribosomes, circular DNA, and specialized surface structures.

Syllabus
First assessment 2025
Objective
A2.2.5
Level
HL

Exam analysis

Chance of appearing10%of analysed past papers
Latest appearanceMay 2025
Most common paperPaper1
Typical marks1–2

Common command terms

  • Identify
  • Compare
  • Label
  • Outline
  • State
  • Draw
  • Distinguish
  • Annotate

Scoring notes

Common mistake
Assigning a nucleus or membrane-bound organelles to a prokaryotic cell.

Recent exam appearances

May 2025Paper1B ["HL"] · TZ12(b)[ 1 ]A2.2.5—Prokaryote cell structure
May 2024Paper2 ["HL"] · TZ28(a)[ 4 ]A2.2.5—Prokaryote cell structure
May 2023Paper1 ["HL"] · TZ12[ 1 ]A2.2.5—Prokaryote cell structure
May 2022Paper2 ["HL"] · TZ22(b)(i)[ 2 ]A2.2.5—Prokaryote cell structure
May 2019Paper2 ["HL"] · TZ13(a)[ 4 ]A2.2.5—Prokaryote cell structure
Practice this objective

Coverage 2012–2025 · Updated 15 Jul 2026

Concept essentials

  • Prokaryotic DNA occupies a nucleoid rather than a membrane-bounded nucleus.
  • Bacterial cytoplasm contains 70S ribosomes.
  • The main chromosome is commonly circular and plasmids may carry additional genes.
  • A peptidoglycan wall supports and protects most bacterial cells.
ConceptIB Biology HL