Question

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

(A) synthesis of small RNA polymers by ribozymes

(B) formation of molecular aggregates with selectively permeable membranes

(C) formation of protocells that use DNA to direct the polymerization of amino acids

(D) abiotic synthesis of organic molecules.

Short answer

1. The statement “synthesis of small RNA polymers by ribozymes” isfalse.

2. The statement “formation of molecular aggregates with selectively permeable membranes” isfalse.

3. The statement “formation of protocells that use DNA to direct the polymerization of amino acids” is true.

4. The statement “abiotic synthesis of organic molecules” is false.

Step-by-step solution

Origin of life

A complex process led to the creation of the Earth. Its surface has changed dramatically over millions of years. The planet has been active since it began accumulating gas and dust during its accretionary phase. This ultimately led to the origin of life on Earth.

Explanation of option (A)

In low yield, enhanced polymerase ribozyme can produce aptamers, ribozymes, and even tRNAs. The polymerase may replicate nucleic acids as part of an RNA-catalyzed PCR, multiplying tiny RNA templates 10,000-fold.

Thus, the synthesis of small RNA polymers by ribozyme is a discovered process.

Therefore, the given statement is false.

Explanation of option (B)

There has long been an understanding that cellular signaling pathways are regulated by cellular clustering in the plasma membrane. Recent breakthroughs in microscopy, including super-resolution, have made it possible to observe nanoscale molecular clusters in plasma membranes.

Thus, molecules aggregation with the selectively permeable membrane is a possible technique.

Therefore, the given statement is false.

Explanation of option (C)

The polymerization of amino acids is a complex biological process that requires numerous proteins and cofactors to work together at different sites in the cell. Despite specific technological achievements in creating synthetic protocells, the synthesis of amino acids directly from DNA has yet to be achieved.

Thus, polymerization of amino acids has not been possible till now.

Therefore, the given statement is true.

Explanation of option (D)

Nonliving elements are said to have given rise to life. The formation of biological molecules, such as amino acids, simple sugars, and simple oligomers of these substances, is attributed to the interaction between heat, UV radiation, and other factors on primordial gases.

Thus, abiotic synthesis of organic molecules is also a possible process.

Therefore, the given statement is false.