Question

what is right and left handed fashion of dna? G-C,A-Tare equimolar?true or false :deoxythymidine is a monomer nucleotide of dna.?

Answer 1

The DNA duplex model proposed by Watson and Crick is right handed spiral and is called B-DNA. The diameter of the helix is 20 Å. Base pairs present turn of helix is 10. Repeating unit is mononucleotide. It is stable and physiologically active form.
Another model of DNA occurs which is left handed and is called Z-DNA. The diameter of the helix is ​18 Å.Base pairs present per turn of helix is 12. Repeating unit is dinucleotide.
In double helix DNA, molar amount of adenine is always equal to the molar amount of thymine and similalry molar amount of guanine is always equal to molar amount of cytosine. Ths is known as Chargaff's rule.