Q BankQuestion BankDocsDocuments

B2.2.7 (HL)—Free ribosomes vs. rough ER

Free ribosomes and rough ER-bound ribosomes both synthesize proteins, but their products usually have different cellular destinations and processing routes.

Syllabus
First assessment 2025
Objective
B2.2.7
Level
HL

Exam analysis

Chance of appearing10%of analysed past papers
Latest appearanceNovember 2024
Most common paperPaper1
Typical marks1

Common command terms

  • Identify
  • State
  • Outline
  • Distinguish

Scoring notes

Common mistake
Reversing the destinations of free ribosome and bound ribosome products.

Recent exam appearances

November 2024Paper2 ["HL"] · TZ02(c)[ 1 ]B2.2.7 (HL)—Free ribosomes vs. rough ER
May 2024Paper1 ["HL"] · TZ129[ 1 ]B2.2.7 (HL)—Free ribosomes vs. rough ER
November 2023Paper3 ["HL"] · TZ23(a)(ii)[ 1 ]B2.2.7 (HL)—Free ribosomes vs. rough ER
November 2023Paper3 ["HL"] · TZ23(a)(i)[ 1 ]B2.2.7 (HL)—Free ribosomes vs. rough ER
November 2021Paper1 ["HL"] · TZ028[ 1 ]B2.2.7 (HL)—Free ribosomes vs. rough ER
Practice this objective

Coverage 2014–2024 · Updated 15 Jul 2026

Concept essentials

  • Free ribosomes synthesize proteins mainly used in the cytoplasm.
  • Rough ER-bound ribosomes synthesize proteins for secretion, membranes, or lysosomes.
  • Polysomes indicate repeated translation of the same mRNA.
  • Secretory cells often contain abundant rough ER and Golgi apparatus.
ConceptIB Biology HL