CAPF AC 2023 Q23: Science & Technology – Biology
Both starch and glycogen are made up of glucose, however:
- (a) starch is present in liver and glycogen is present in red blood cells.
- (b) glycogen is made in animal cells, but starch is made in plant cells.
- (c) both starch and glycogen are present in animal and plant cells.
- (d) both starch and glycogen are present in plant cells only.
Answer: (b) glycogen is made in animal cells, but starch is made in plant cells.
Explanation
Starch and glycogen
How to think: both are storage forms of glucose.
The difference is who makes them.
Plants store glucose as starch.
Animals store it as glycogen.
| Feature | Starch | Glycogen |
|---|---|---|
| Made by | Plant cells | Animal cells (also fungi) |
| Stored in | Seeds, tubers, grains | Liver and muscles |
| Structure | Amylose and amylopectin | Highly branched |
| Nickname | Plant storage food | Animal starch |
The third glucose polymer: cellulose forms the cell wall of plants.
Humans cannot digest it.
Answer: (b).
Why each option is right or wrong
- (a) Incorrect. The liver stores glycogen, not starch; red blood cells store neither.
- (b) CORRECT. Glycogen is made in animal cells and starch in plant cells.
- (c) Incorrect. Starch is not made by animal cells, nor glycogen by plant cells.
- (d) Incorrect. Glycogen is not found in plant cells.
Key point
Polysaccharides of glucose: starch (plants, storage), glycogen (animals, storage in liver and muscle), cellulose (plants, structure). Chitin: exoskeleton of insects and cell wall of fungi.
Remember
Plants: starch. Animals: glycogen.
Common mistakes
- Swapping the two and placing starch in the liver.
- Mixing up glycogen (a carbohydrate) with glucagon (a hormone).
- Thinking animals store extra glucose as starch because they eat starch.
Exam tip
Educated guess: glycogen is nicknamed animal starch. That one phrase tells you which belongs where.
Sources
- NCERT Class XI Biology — Biomolecules (polysaccharides)
- NCERT Class X Science — Life Processes (nutrition)