Chapter 11, Problem 1TY

Why did researchers initially believe that the genetic material was composed of proteins?

1. a. Proteins are more biochemically complex than DNA.
2. b. Proteins are found only in the nucleus, but DNA is found in many areas of the cell.
3. c. Proteins are much larger molecules and can store more information than DNA.
4. d. all of the above
5. e. both a and c

Summary Introduction

Introduction: Every organism present in nature contains genetic material. There are two types of genetic material and they are DNA and RNA. DNA stands for “deoxyribonucleic acid” and RNA represents “ribonucleic acid”. In eukaryotes, the genetic material is enclosed by a well-defined nuclear membrane. However, prokaryotic organisms lack a nuclear membrane.

Answer to Problem 1TY

Correct answer: The researchers initially believed that the genetic material was composed of proteins because proteins are more biochemically complex than DNA. Hence, the correct answer is option a.

Explanation of Solution

Reason for correct answer:

The scientists in the earlier time have a great misconception that protein was the genetic material. They believed this because they were aware of the involvement of the protein in most of the cellular activities. The variety of proteins also paved way to this misconception. They were not much aware of DNA. They believed that since proteins are more biochemically complex than DNA, it must be the genetic material.

Option a. is given as “Proteins are more biochemically complex than DNA”.

Proteins are more biochemically complex than DNA. Therefore, the researchers initially believed that the genetic material was composed of proteins. Hence, the correct answer is option a.

Reasons for incorrect answer:

Option b. is given as, “Proteins are found only in the nucleus, but DNA is found in many areas of the cell”.

The nucleus contains both DNA and proteins (histones). It is protein and not DNA that is found in many areas of the cell. Proteins are present in every part of the cell, such as in cytoplasm, organelle, nucleus, and cell membrane. However, DNA is the constituent of the nucleus only. Hence, option b. is incorrect.

Option c. is given as, “Proteins are much larger molecules and can store more information than DNA”.

The earlier scientists believed that proteins are the major constituents of the genetic material. They had this misconception on the basis that proteins are more biochemically complex than DNA. This belief of the researchers had no association with the larger size of proteins. Hence, option c. is incorrect.

Option d. is given as, “all of the above”.

The earlier scientist believed that the genetic material was composed of proteins as proteins are more biochemically complex than DNA. They did not make this conception due to the other reasons mentioned in option b. and c. Hence, option d. is incorrect.

Option e. is given as, “both a. and c”.

The option a. correctly describes the reason due to which the researchers initially believed that the genetic material was composed of proteins and not DNA. However, the option c. has no role in this misconception. Hence, option e. is incorrect.

Hence, the options b., c., d., and e. are incorrect.

Conclusion

Therefore, the reason that the researchers initially believed that the genetic material was composed of proteins was that proteins are more biochemically complex than the DNA.