In a strand of nucleic acid, two nucleotides are linked together by:
1. 3’ – 5’ phosphodiester bond
2. 5’ – 3’ phosphodiester bond
3. 2’ – 5’ phosphodiester bond
4. 3’ – 1’ phosphodiester bond

Griffith’s transformation experiment in Streptococcus pneumoniae demonstrated that:
1.    Heat-killed virulent bacteria failed to produce disease in mice
2.    Live non-virulent bacteria failed to produce disease in mice
3.    Heat-killed virulent bacteria transformed non-virulent bacteria into virulent form
4.    Live virulent bacteria alone produced fatal infection in mice

What facilitates the opening of the helix during the elongation step of transcription?

The repressor of the lac operon is:

The base pairing in a double stranded DNA is correctly described as:

In a transcription unit, RNA polymerase binds to:

The distance between a base pair in the DNA double helix is approximately:

Transcription and translation can be coupled in:

In some viruses, the flow of genetic information is from RNA to DNA. These viruses are:

In a transcription unit, with respect to structural genes, the promoter is located: