A three-mark increase in Biology after re-evaluation changed the outcome of the CBSE Class 12 examination for Aditya Mishra of Bokaro. The revised score took his total to 498 out of 500 in his best five subjects, making him a joint national topper in the Science stream.When the CBSE results were declared on May 13, Aditya had scored 99.20 per cent overall. He received 96 marks in Biology, but his teachers felt the score was lower than expected. At the time, Aditya was focused on preparing for the NEET examination and did not pay much attention to the result.“My parents and teachers submitted the paper for re-evaluation. I received an additional three marks, taking my biology score to 99,” he said on Tuesday.A student of DPS Bokaro, Aditya scored 100 marks each in English Core, Chemistry and Painting, along with 99 marks in Physics and Biology.School principal AS Gangwar said the institution was proud of his achievement. He described Aditya as a sincere and consistent student who had always shown dedication towards academics.“We are very happy that one of our meritorious students, Aditya Mishra, became national topper in the Science stream of the CBSE Class 12 examination after re-evaluation,” Gangwar said.He added that Biology had always been Aditya’s favourite subject and that the school felt the paper deserved a review after seeing the marks awarded initially.According to a teacher, Aditya shared the top position in the Science stream with Sonakshi Goyal of Kanpur.The son of Prajesh Chandra Mishra, chief general manager (finance) at SAIL Refractory Unit, and homemaker Sushmita Mishra, Aditya is now focused on his medical career. He also appeared in the NEET-UG re-examination held on Sunday.“I had also appeared for the NEET examination in May and the papers were good. But it was cancelled. I appeared for the re-examination and am expecting positive results,” he said.Aditya said he studied for five to six hours daily and used both his mobile phone and laptop while preparing for the entrance test. Looking ahead, he wants to join the medical profession.“I want to pursue my career in the medical field. I want to serve mankind as a doctor,” he said. His father credited the school and teachers for playing a key role in his son’s success.