Question

The following picture depicts the DNA what is the structure of DNA
A. Spherical
B. Double helix
C. Dumbell
D. Renal and longitudinal

Answer 1

The DNA is double stranded and its structure was known as x-ray diffraction. The double helix structure of DNA was given by two scientists named Watson and crick.

Complete step-by-step answer: The DNA is made by two polynucleotide chains. Base of DNA is made by sugar and phosphate.
Both chains are of antiparallel polarity to each other. Polarity of one is 5 and the other is 3 to 5.
Nucleotide bases are paired by hydrogen bonds. Adenine and thymine are found at opposite strands and attached with hydrogen bonds.
Similarly cytosine and guanine found at opposite strands and attached with 3 H-bonds.
Both strands are coiled in clockwise direction.
H-bonds provide stability to the double helix.

Additional information: DNA is a long polymer of deoxyribonucleotides that has a double helical structure with a sugar-phosphate backbone where nitrogenous bases project inside and are paired together with the help of hydrogen bonds, that forms the double stranded structure of the DNA.

So, the correct answer is “Option B. Double helix”.

Note: Pitch of every coil in DNA helix is 3.4 nm and 10 base pairs are present in each coil. Distance between every two pairs of nucleotide bases is 0.34nm.