Molecular Basis of Inheritance Test - 17

Hershey and Chase proof for DNA as the genetic material.

Lagging strand is replicated strand of DNA which is formed in short segments called Okazaki fragments. Its growth is discontinuous. The direction of growth of the lagging strand is 3’ → 5’ though in each Okazaki fragment it is 5’ → 3’

rRNA (Ribosomal RNA) is most abundant in all types of RNA. Hence it will present in highest amount.

Histones are a set of positively charged basic proteins.

Wherein Histones are rich in the basic amino acid residues lysines and arginines. They are organized to form a unit of eight molecules called histone octamer. The DNA is condensed into a Chromatin Fibre.

23 S rRNA from large subunit of ribosome acts as structural RNA as well as ribozyme.

The DNA-dependent RNA polymerase catalyze the polymerisation in only one direction that is 5→3, the strand with polarity 5→3 act as template and is called as template strand.

Because all the other Condons are stop Condons but AUG is the start Condon.

Lac operon is and inducible operon. Lactose is the substrate for the enzyme β- galactosidase and it also regulates switching on and off of the operon. Hence, it is termed as inducer.

Chargaff's rule 1 is that the number of guanine units approximately equals the number of cytosine units and the number of adenine units approximately equals the number of thymine units.

Chargaff's rule 2 is that the composition of DNA varied from one species to another.

Activators and repressors -

In a transcription unit, the activity of RNA polymerase at a given promoter is in turn regulated by interaction with accessory proteins which affect its ability to recognized- wherein. These regulatory proteins can both positively (activators) and negatively (repressors). A Balbiani ring is a large chromosome puff. Balbiani rings are diffused uncoiled regions of the polytene chromosome that are sites of RNA transcription and protein synthesis.