Question

Following reports that the amount of DNA varied over time within cells, scientists in the early 1900s concluded that the genetic material had to be

A) DNA.
B) RNA.
C) protein.
D) lipids.
E) carbohydrates.

Answer 1

The belief that proteins carried genetic information was debunked by Hershey and Chase's experiments in the 1950s, which confirmed that DNA, not proteins, is the genetic material responsible for heredity.

Step-by-step explanation:

Discovery of DNA as the Genetic Material

Initially, scientists in the early 20th century thought that proteins were the carriers of genetic information due to their complexity. It wasn't until the Hershey and Chase experiments in the 1950s that the scientific community began to accept DNA as the genetic material. Hershey and Chase used radioactive labeling to trace the genetic material that bacteriophages were transferring into bacteria, finding that it was DNA, not proteins or any other molecules, thus sealing the deal on DNA's pivotal role in heredity.

The misconception that proteins were the genetic material was due to their diverse structure with 20 different amino acids, assumed capable of encoding the vast complexity of biological information, in contrast to DNA's deceptively simple structure with only four nucleotides. However, bacteriophage experiments and subsequent understanding of DNA's structure illustrated its capability as the molecule of heredity. Confirming that DNA carries the code of life was a cornerstone in the field of molecular biology.