Match List-I with List-II
| List-I | List-II |
|---|---|
| Terms | Features |
| (A) Selectable marker | (I) Site that commonly used for cutting the DNA by restriction enzyme |
| (B) Origin of replication | (II) Removes nucleotides from the ends of the DNA |
| (C) Exonuclease | (III) Helps in identification and elimination of non-transformants |
| (D) Recognition site | (IV) The sequence responsible for controlling the copy number of linked DNA |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A) - (III), (B) - (IV), (C) - (II), (D) - (I)
(A) Selectable marker — this matches (III) Helps in identification and elimination of non-transformants. A gene such as one for antibiotic resistance lets only the transformed cells grow on a medium with that antibiotic.
(B) Origin of replication — this matches (IV) The sequence responsible for controlling the copy number of linked DNA. Ori is where replication starts, so it also decides how many copies of the linked DNA are made.
(C) Exonuclease — this matches (II) Removes nucleotides from the ends of the DNA. “Exo” means outside: it works from the ends, unlike an endonuclease, which cuts inside the strand.
(D) Recognition site — this matches (I) Site that commonly used for cutting the DNA by restriction enzyme. It is the palindromic sequence where a restriction enzyme binds and cuts.
NCERT Extract:
Cloning Vectors – “… The following are the features that are required to facilitate cloning into a vector.
(i) Origin of replication (ori) : This is a sequence from where replication starts and any piece of DNA when linked to this sequence can be made to replicate within the host cells. This sequence is also responsible for controlling the copy number of the linked DNA. …
(ii) Selectable marker : In addition to ‘ori’, the vector requires a selectable marker, which helps in identifying and eliminating non-transformants and selectively permitting the growth of the transformants.”