IISER IAT case studies
IISER IAT · Put your knowledge to work in context.
The IISER Aptitude Test (IAT) is the entrance examination used within the IISER Admissions 2026 cycle for admission to the Indian Institutes of Science Education and Research. It is aimed at students who have completed or are completing their higher secondary schooling and want to enter a research-oriented undergraduate science programme rather than a professional or engineering course. The IISER IAT case studies are 5 cases and about 3,379 words.
1The inhibitor that lowered both numbers
An undergraduate assays a liver enzyme with substrate S and a compound X sold as a 'competitive inhibitor'. Each 1.0 mL reaction contains 0.02 µg enzyme, 50 mM buffer pH 7.4, and 1% DMSO (used to dissolve X).
685 words, about 3 min2A carrier risk that depends on which test is done first
A 28-year-old woman asks about her risk of having a child with spinal muscular atrophy, an autosomal recessive condition. Her brother is affected; she is healthy.
623 words, about 3 min3A buffer that misses its target pH
A student must prepare 250.0 mL of a pH 5.00 buffer from 0.200 M acetic acid (pKa = 4.76) and 0.200 M sodium acetate. Using the Henderson–Hasselbalch ratio [A⁻]/[HA] = 10^(5.00 − 4.76) = 1.74, she mixes 60.0 mL of the acid with 105.0 mL of the acetate solution (measured with a graduated cylinder) and dilutes to the mark with deionized water.
661 words, about 3 min4Five doors, two different hosts
A game show has five closed doors; exactly one hides a car and the rest hide goats. In version A, the host knows where the car is, always opens three of the other four doors to reveal goats (never the car, never your door), and then offers you the single remaining unopened door.
749 words, about 4 min5The battery that cannot deliver the bulb's rating
A student is given a '12 V, 36 W' car bulb and a battery pack. With a 0.50 A load the terminal voltage is 11.6 V; with a 2.00 A load it is 10.0 V.
661 words, about 3 min