Question

Given the state of knowledge at the time of the Avery, MacLeod, and McCarty experiment, why was it difficult for some scientists to accept that DNA is the carrier of genetic information? A) Both proteins and DNA were the major chemical components of chromosomes. Since proteins are constructed during translation and also can cut double-stranded DNA at particular base sequences, it looked like proteins are the genetic material. B) Genes possess a variety of functions. Since proteins can contain up to 20 different amino acids, while DNA is made up of only four different nucleotides, proteins should have more functional variations. It seemed likely that proteins should be the genetic material. C) The carrier of genetic information should take part in gene expression. Since tRNAs recognize the information encoded in the mRNA codons and carry the proper amino acids for construction of the protein during translation, they were thought to be the genetic material.

Answer 1

The difficulty in accepting that DNA is the carrier of genetic information was primarily due to the following reason:

A) Both proteins and DNA were the major chemical components of chromosomes. Since proteins are constructed during translation and also can cut double-stranded DNA at particular base sequences, it looked like proteins are the genetic material.

At the time of the Avery, MacLeod, and McCarty experiment, scientists knew that chromosomes, which were believed to carry genetic information, were composed of both proteins and DNA. Proteins were known to have a diverse range of functions, and it was challenging to imagine how the relatively simple structure of DNA, made up of just four nucleotides, could encode the vast complexity of genetic information. Additionally, the fact that proteins could cut DNA at specific base sequences suggested that proteins might be involved in genetic processes.

This uncertainty and the complexity of the relationship between DNA and proteins led to skepticism about whether DNA was the genetic material. It took further research, including the Hershey-Chase experiment, to confirm that DNA, not proteins, carries genetic information.

Step-by-step explanation: