In recent past human chromosomes have been studied by a technique using specific, often fluorescent dyes, known as

Clover leaf secondary structure of $tRNA$ has a loop for

Select the two correct statements out of the four $(i -iv)$ statements given below about lac operon.

$(i)$ Glucose or galactose may bind with the repressor and inactivate it.

$(ii)$ In the absence of lactose the repressor binds with the operator region.

$(iii)$ The z­gene codes for permease.

$(iv)$ This was elucidated by Francois Jacob and Jacques Monod.

The correct statements are

Who used the word "chromosome''

Depending upon size and centromere position, the $46$ chromosomes have been divided into a number of groups