Questions | Mimamsa 2021

Biology Prelims question 2


Collision Course

Plasmid A of size 3.6 kbp is inserted into a bacterium Whata pujarii and the location of the replication forks is noted every 5 minutes. This is repeated in the presence of IPTG,
which continuously induces transcription of the lac operon. On performing the
experiment with plasmid B, which is identical to A except for the position of the ori, a
peculiar difference is observed as shown in the graphs.

(a) Give reasons for the difference between +IPTG and -IPTG cases.
(b) Give reasons for the greater difference between +IPTG and -IPTG cases in B than in A.

Page 2/2