Question

The Avery et al. (1944) contribution to an understanding of molecular biology was ________.

a) Discovery of the structure of DNA
b) Identification of RNA as the genetic material
c) Demonstration that DNA is the genetic material
d) Elucidation of the genetic code

Answer 1

Avery et al. (1944) crucially demonstrated that DNA, not protein, is the genetic material, a cornerstone discovery that transformed our understanding of the molecular mechanisms of inheritance.

Step-by-step explanation:

The contribution of Avery et al. (1944) to an understanding of molecular biology was the demonstration that DNA is the genetic material. This was a groundbreaking discovery in the field of genetics and laid the foundation for modern molecular biology. Before this discovery, proteins were considered more likely to be the genetic material due to their complexity and variability. However, the work of Oswald Avery, Colin McLeod, and Maclyn McCarty identified DNA as the substance that was responsible for the transformation observed by Frederick Griffith in his 1928 experiments on bacteria.

This identification was later confirmed by Hershey and Chase in 1952, who demonstrated that it was DNA, not protein, that viruses used to infect and replicate within bacteria. The discovery that DNA is the genetic material showed that it is the DNA that contains the instructions for life and hereditary transmission. The subsequent discovery of the structure of DNA by James Watson and Francis Crick in 1953 further solidified our understanding of DNA as the carrier of genetic information.