Question

Even before the structure of DNA was solved, studies indicated that the genetic material must have the following properties:

-be able to store information;

-be faithfully replicated and be passed on from generation to generation; and

-allow for changes, and thus evolution, to occur.

Explain how the structure of the double helix showed that DNA had these properties. Write one or two sentences per point.

Answer 1

The properties of DNA were very well understood in terms of genetics and heridity much before the structure of DNA was knwon. The properties can be justified with respect to the presently known structure of DNA as discussed below:

Answer 1: The contemporary structure of DNA shows that the composition of nitrogenous bases and their sequence determines the genetic information in a cell, hence enables the DNA to store information.

Answer 2: The semi-quantitative mode of replication of DNA ensures that the information is passed from one generation to another at the time of cell division.

Answer 3: The mutational changes occuring in the DNA replication allow the chances for change in the original sequence, hence evolution to take place.