Match List-I (terms used in the Human Genome Project) with List-II.
| List-I | List-II |
| (A) Expressed Sequence Tags (ESTs) | (I) Vectors used to clone the random DNA fragments in bacteria and yeast |
| (B) Sequence Annotation | (II) Assigning different regions in the sequence with functions |
| (C) BAC and YAC | (III) Repetitive DNA sequences used, along with polymorphism of restriction endonuclease recognition sites, to assign genetic and physical maps |
| (D) Microsatellites | (IV) Identifying all the genes that are expressed as RNA |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A-IV, B-II, C-I, D-III
(A) Expressed Sequence Tags (ESTs) — this matches (IV) Identifying all the genes that are expressed as RNA. This was one of the two main approaches of the project. It looks only at genes that are actually transcribed into RNA.
(B) Sequence Annotation — this matches (II) Assigning different regions in the sequence with functions. In the second approach, the whole genome, coding and non-coding, was sequenced first. The functions of the different regions were worked out afterwards, and this step is annotation.
(C) BAC and YAC — this matches (I) Vectors used to clone the random DNA fragments in bacteria and yeast. BAC (bacterial artificial chromosome) and YAC (yeast artificial chromosome) carried the small DNA fragments into the hosts, where each fragment was amplified for sequencing.
(D) Microsatellites — this matches (III) Repetitive DNA sequences used, along with polymorphism of restriction endonuclease recognition sites, to assign genetic and physical maps. Microsatellites are short repeats that vary between people, so they serve as markers when genetic and physical maps are set on the genome.
NCERT Extract:
Human Genome Project – “… Methodologies : 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). … The commonly used hosts were bacteria and yeast, and the vectors were called as BAC (bacterial artificial chromosomes), and YAC (yeast artificial chromosomes).”
Human Genome Project – “… Another challenging task was assigning the genetic and physical maps on the genome. This was generated using information on polymorphism of restriction endonuclease recognition sites, and some repetitive DNA sequences known as microsatellites (one of the applications of polymorphism in repetitive DNA sequences shall be explained in next section of DNA fingerprinting).”