In DNA, the "rungs" between the two strands of DNA are formed from the

a. covalent bonds between nitrogen base pairs.
b. ionic bonds between the phosphate pairs.
c. ionic bonds between the nitrogen base pairs.
d. hydrogen bonds between nitrogen base pairs.
e. phosphodiester bonds between the deoxyribose sugars.

option d.hydrogen bonds between nitrogen base Pairs

Explanation:

DNA is called a Deoxyribonucleic acids, it contains hereditory information in the cell. DNA is located in nucleus of human cell. DNA consist of nucleotide strands that comprises of a sugar and oxyribose bound on a partto a phosphate group and bound on the other part to a nitrogenous base. The Nitrogenous base consist of Adenine, thymine, guanine and cytosine which are complementary base Pairs. They are grouped into 2 distinct classes called purines (double-ringed structures) and pyrimidines (single-ringed structures). The nitrogenous bases forms a ladder and pairs with bases on the other side commonly called rungs. Each complementary nucleotides purine with pyrimidine are held together by hydrogen bonds.A hydrogen bond is a known as chemical bond that is relatively weak and occurs only between hydrogen atoms along with or and electronegative atoms, e.g oxygen, nitrogen e.t.c. Hydrogen bonds usually occur in short length or distances and are formed quickly or easily and ca also broken.

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