Q BankQuestion BankDocsDocuments

B2.2.5 (HL)—Chloroplast adaptations

Chloroplasts contain thylakoid, grana, and stroma compartments that organize light-dependent reactions, proton gradients, and carbon fixation during plant cell photosynthesis.

Syllabus
First assessment 2025
Objective
B2.2.5
Level
HL

Exam analysis

Chance of appearing4%of analysed past papers
Latest appearanceNovember 2024
Most common paperPaper1
Typical marks1

Common command terms

  • Label
  • Explain
  • Identify
  • State
  • Draw
  • Describe

Scoring notes

Common mistake
Confusing chloroplast grana with mitochondrial cristae.

Recent exam appearances

November 2024Paper1 ["HL"] · TZ030[ 1 ]B2.2.5 (HL)—Chloroplast adaptations
May 2021Paper2 ["HL"] · TZ26(b)[ 4 ]B2.2.5 (HL)—Chloroplast adaptations
November 2016Paper1 ["HL"] · TZ031[ 1 ]B2.2.5 (HL)—Chloroplast adaptations
May 2013Paper1 ["HL"] · TZ129[ 1 ]B2.2.5 (HL)—Chloroplast adaptations
May 2012Paper1 ["HL"] · TZ230[ 1 ]B2.2.5 (HL)—Chloroplast adaptations
Practice this objective

Coverage 2012–2024 · Updated 15 Jul 2026

Concept essentials

  • Grana are stacks of thylakoids that increase photosynthetic membrane surface area.
  • Thylakoid membranes hold photosystems, electron transport chains, and ATP synthase.
  • Small thylakoid spaces allow rapid proton accumulation.
  • The stroma contains enzymes for light-independent carbon fixation.
ConceptIB Biology HL