Question

An organism living at an extremely hot place is likely to have a high GC content in its DNA. Give a reason to explain.

Study the given below single strand of deoxyribonucleic acid depicted in the form of a "stick" diagram with 5' – 3' end directionality, sugars as vertical lines and bases as single letter abbreviations and answer the questions that follow. (a) Name the covalent bonds depicted as (a) and (b) in the form of slanting lines in the diagram. (b) How many purines are present in the given "stick" diagram ? (c) Draw the chemical structure of the given polynucleotide chain of DNA.

In a DNA, percentage of thymine is 20. What is the percentage of Guanine ?

The base sequence in one of the strands of DNA is : 'TAGCATGAT' (a) Give the base sequence of its complementary strand. (b) How are these base pairs held together in DNA molecule ? (c) Explain the base complementarity rule. Name the scientist who framed this rule.