Question

Which purine & pyrimidine bases are paired together by H bonds in DNA?
A. AC and GT
B. GC and AT
C. GA and TC
D. None of the above

Answer 1

Hint: The nucleus is a cell-organelle that contains the hereditary information. Heredity information is the information that is transferred from parents to offspring. The nuclear membrane is well developed in eukaryotes than in prokaryotes.

Complete answer:
DNA stands for Deoxyribonucleic acid. It consists of a double helical ladder shaped structure. The DNA is a polymer that consists of many small units called Nucleotides. Many nucleotides join linearly to form a DNA strand. The nucleotide consists of Nitrogen base, deoxyribose pentose sugar and the phosphate group in the form of Phosphoric acid. The nitrogen base and the deoxyribose pentose sugar combine to form nucleosides. In other words, nucleoside is a nucleotide without phosphate group. The name deoxyribose pentose sugar came from the structure of sugar in that it has a pentose ring and is oxygen deficient hence the name deoxyribose pentose sugar. There are two kinds of nitrogen bases in DNA- Purine and Pyrimidine. Purine bases are adenine and guanine whereas thymine and cytosine are pyrimidine bases. Adenine always pairs with thymine with the help of two weak hydrogen bonds whereas the guanine always pairs with cytosine with the help of three weak hydrogen bonds.

Hence, the correct answer is option (C)

Note: Watson and Crick studied the structure of DNA and determined that the structure of DNA is double helical. The structure is just like a spiral ladder. RNA is also the genetic material in certain bacteria and viruses. DNA can be used in many criminal investigations and forensics study for the studies of various crimes.