Solved UPSC CDS/OTA Question
A solved UPSC CDS/OTA PYQ — decoded step-by-step.
Solve it the standard way once — then learn the shortcut.
Q · Circulatory SystemMedium · 45s
Which part of the heart prevents the backflow of blood?
TopicCirculatory System
Question Typemultiple choice
DifficultyMedium
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
Every step explained — no skipped algebra.
Valves ensure unidirectional blood flow.
Final Answer: Option B — Valves