A Levels Biology (9700)•9700/11/M/J/21

Explanation
Macromolecules unique to animal cells
Steps:
- Identify macromolecules as large biomolecules: carbohydrates (e.g., polysaccharides), proteins, nucleic acids, lipids.
- Recall animal cells store energy as glycogen (polysaccharide) and use collagen (protein) for structural support in connective tissues.
- Eliminate pairs with plant-specific or non-macromolecular components.
- Verify pair B contains only animal-exclusive macromolecules.
Why B is correct:
- Collagen is a fibrous protein defining animal extracellular matrix; glycogen is the branched polysaccharide for glycogen storage disease in animals, per biochemical definitions.
Why the others are wrong:
- A: Amylopectin is a plant starch component, absent in animals.
- C: Deoxyribose is a monosaccharide (not a macromolecule); starch is plant-specific.
- D: Sucrose is a disaccharide (not a macromolecule).
Final answer: B
Topic: Carbohydrates and lipids
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