Topic Osmosis
Asked 7 times across 3 UPSC exams over 6 years (2017–2023), peaking in 2021.
Key insights
- Most tested in CDS — 3 of 7 PYQs
- Most asked in 2021
- Recurs across 5 years (2017–2023)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
CDS 2017 → CAPF 2019 → NDA 2021
How the concept evolved
Rising — more than half its appearances (7 of 7) are since 2016.
Related concepts
Ideas UPSC tests alongside this one — keep exploring.
Sample questions
You've seen the pattern — here are a few of the actual PYQs.
CDS2023
If the red blood cells (RBCs) of human blood are isolated and are diluted in normal saline (an isotonic solution to blood), what will happen to the RBCs?
- A The RBCs will swell
- B The RBCs will swell and burst
- C The RBCs will shrink
- D No change in the diameters of the RBCs ✓
✓ Correct answer: (D)
Science & Technology › Biology & Health
NDA2023
During a laboratory experiment, a student immerses epidermal leaf peel in a hypertonic solution. After some time, the student examined the cells under a microscope and observed that :
- A the cells swelled.
- B the cells were plasmolysed. ✓
- C the cells built up turgor pressure.
- D the cells size was unaffected.
✓ Correct answer: (B)
Science & Technology › Biology & Health
NDA2022
Which one of the following will be resulted when an animal cell is surrounded by a medium with lower concentration of water?
- A Cell will lose water ✓
- B No change in movement of water
- C Cell will gain water
- D Cell will swell up
✓ Correct answer: (A)
Science & Technology › Biology & Health
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