Chapter 24, Problem 1TYU

Which of the following steps has not yet been accomplished by scientists studying the origin of life?

1. A.    synthesis of small RNA polymers by ribozymes
2. B.     abiotic synthesis of polypeptides
3. C.     formation of molecular aggregates with selectively permeable membranes
4. D.    formation of protocells that use DNA to direct the polymerization of amino acids

Summary Introduction

Introduction:

In studying the evolution of life, scientists have accomplished a lot. For example: From creating the early earth atmosphere in “The Stanley Miller experiment” for reconstructing the “Structure of early human ancestors”.

Answer to Problem 1TYU

Correct answer:

Science today has advanced a lot. Polypeptides, selectively permeable membranes RNA from ribozymes have been synthesized in-vitro. Therefore, option (D) is correct.

Explanation of Solution

Reason for the correct statement:

A protocell or a protobiont was the first cell and the precursor of prokaryotes. It is made from inorganic components and bound by a lipid membrane. Scientists have not yet been able to synthesize a protocell that uses DNA for protein synthesis in the lab.

Option (D) is given as “formation of protocells that that use DNA to direct the polymerization of amino acids”.

“The formation of protocells that that use DNA to direct the polymerization of amino acids has not yet been accomplished by scientists studying the origin of life”, it is the right answer.

Hence, the option (D) is correct.

Reasons for the incorrect statements:

Option (A) is given as “synthesis of small RNA polymers by ribozymes”.

This has been accomplished by the scientists. So, it is a wrong answer.

Option (B) is given as “abiotic synthesis of polypeptides”.

The abiotic synthesis of polypeptides has been done in-vitro by the scientists. So, it is a wrong answer.

Option (C) is given as “formation of molecular aggregates with selectively permeable membrane”.

This formation of molecular aggregates with selectively permeable membrane too has been accomplished. So, it is a wrong answer.

Hence, options (A), (B) and (C) are incorrect.

Conclusion

In the study of origin of life, scientists have accomplished a lot but the artificial synthesis of a protocell that uses DNA for polymerization of amino acids is yet to be accomplished.