E. coli was used as a tool for the discovery of semi-conservative replication by Messelson and Stahl. E. coli, along with T2 phage, was used for discovery of transduction.

If a DNA molecule is 68 Angstrom long, it would contain 20 base pairs. The distance between two bases is 3.4 Angstrom. Thus, number of base pairs in 68 Angstrom long molecule is 68/3.4 = 20 base pairs.

DNA ligase is a specific type of enzyme that facilitates the joining of DNA strands together by catalysing the formation of a phosphodiester bond. Ligase is involved in formation of a phosphodiester bond starting from the 3'-OH of one Okazaki fragment and the 5'-phosphate of the next on the lagging strand.

Chargaff discovered two rules that helped lead to the discovery of the double helix structure of DNA.
The first rule was that in DNA, the number of guanine units is equal to the number of cytosine units, and the number of adenine units is equal to the number of thymine units.
This hinted at the base pair makeup of DNA.
The second rule was that the relative amounts of guanine, cytosine, adenine and thymine bases vary from one species to another. This hinted that DNA rather than protein could be the genetic material.

In DNA molecule, hydrogen bonds connect the base pairs. Adenine is bonded to thymine by two hydrogen bonds and guanine is attached to cytosine by three hydrogen bonds.

Histones are rich in lysine and arginine. Lysine and arginine are basic amino acids that bind to the acidic ions present in DNA molecules to form a nucleosome.

In a cell, the process of transcription takes place inside the nucleus.
Transcription is the process of copying information from one strand of DNA to RNA.

In human genome, chromosome 1 has the maximum number of genes, whereas chromosome Y has the minimum number of genes. There are 2968 genes in chromosome 1 and 231 genes in chromosome Y.

Mutation in promoter would invariably influence the binding of RNA polymerase to DNA. Promoter sequence contains specific DNA sequences where RNA polymerase can bind and start transcription.

Monocistronic mRNA is a mRNA that encodes only one protein and all eukaryotic mRNAs are monocistronic. Genes in eukaryotes are split and have interrupted coding sequences.