Genome Sequencing Methods — NEET Biology
✅ Asked in NEET 2023Methodologies: The methods involved two major approaches. One approach focused on identifying all the genes that are expressed as RNA (referred to as Expressed Sequence Tags (ESTs). The other took the blind approach of simply sequencing the whole set of genome that contained all the coding and non-coding sequence, and later assigning different regions in the sequence with functions (a term referred to as Sequence Annotation). For sequencing, the total DNA from a cell is isolated and converted into random fragments of relatively smaller sizes (recall DNA is a very long polymer, and there are technical limitations in sequencing very long pieces of DNA) and cloned in suitable host using specialised vectors. The cloning resulted into amplification of each piece of DNA fragment so that it subsequently could be sequenced with ease. The commonly used hosts were bacteria and yeast, and the vectors were called as BAC (bacterial artificial chromosomes), and YAC (yeast artificial chromosomes).
NTA tests whether students understand the two main approaches to genome sequencing: EST (Expressed Sequence Tags) which focuses only on genes expressed as RNA, and Sequence Annotation which sequences the entire genome including non-coding regions. Students commonly confuse ESTs with the complete genome sequence—ESTs only identify expressed genes, while whole genome sequencing captures everything. The key mistake is thinking ESTs represent the full genome; remember that ESTs are selective (RNA-derived), whereas the annotation approach is comprehensive. NEET repeatedly tests this distinction because it's fundamental to understanding how scientists decode genetic information using different strategies.
This paragraph was tested 3 times in NEET.
Expressed Sequence Tags (ESTs) refers to: (NEET 2023)
If a geneticist uses the blind approach for sequencing the whole genome of an organism, followed by assignment of function to different segments, the methodology adopted is called: (NEET 2022)
Expressed Sequence Tags (ESTs) refer to: (NEET 2019)
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.