NSEB case studies
NSEB · Put your knowledge to work in context.
NSEB is the National Standard Examination in Biology, one of the subject papers in the National Standard Examination (NSE) suite run by the Indian Association of Physics Teachers (IAPT). It is a pen-and-paper examination written at registered centres, and it is aimed at strong school-level biology students who want an early, serious benchmark of their grasp of the subject. The NSEB case studies are 5 cases and about 3,803 words.
1Carrier testing in a consanguineous family with spinal muscular atrophy
A couple from a town in Tamil Nadu seeks genetic counselling. The woman, 27, is healthy, but her 19-year-old brother has spinal muscular atrophy (SMA) with homozygous loss of SMN1 exon 7; both her parents are unaffected.
796 words, about 4 min2A sodic, saline-irrigated mustard field that wilts while wet
A farmer near Hisar, Haryana, grows Indian mustard on 4 hectares irrigated only from a tube well of EC 7.8 dS/m with high residual sodium carbonate. Soil pH is 9.1 and exchangeable sodium percentage is 28%.
813 words, about 4 min3A bloom-covered reservoir, a fish kill, and two proposed fixes
A 600-hectare reservoir near Nagpur receives untreated sewage from a town of 90,000 people. Monitoring in May gives: surface chlorophyll a 96 µg/L; total phosphorus 190 µg/L; total nitrogen 2.6 mg/L; Secchi depth 0.4 m; surface dissolved oxygen 11 mg/L at 16:00 but 3 mg/L at 05:00; at 6 m the water has been anoxic since April, with unionised ammonia at 0.9 mg/L.
712 words, about 4 min4Reading a PCR genotyping panel where the controls misbehave
A state seed-testing laboratory receives 40 cotton seed lots certified as non-GM. The routine conventional PCR panel uses primers for the Cauliflower mosaic virus 35S promoter (450 bp product), primers for part of Cry1Ac, and a cotton lectin primer pair as a plant-DNA control.
744 words, about 4 min5Two trekkers at 3,600 m and one oxygen cylinder
Two trekkers ascend from 2,000 m to 3,600 m in about 30 hours. At 3,600 m, trekker A is breathless at rest, has pink frothy sputum, crackles in the right mid-zone, cannot walk heel-to-toe, and has SpO2 71% on room air; he was well at 2,000 m.
738 words, about 4 min