Question

which of the following describes how rna could have formed on early earth?
a rna evolved after dna to carry out reactions while still storing genetic information.
b rna did not originate on earth and was brought to the planet by meteorite strikes.
c rna formed inside ancient bacterial cells to help transfer genetic information during cell division.
d earths early atmosphere contained the materials to form rna, and lightning triggered the reaction.

Explanation:

• Option A: RNA is believed to have been the first genetic material. DNA evolved after RNA. So, the statement that RNA evolved after DNA is incorrect.
• Option B: There is no evidence to suggest that RNA was brought to Earth by meteorite strikes. The current understanding is that RNA formed on Earth.
• Option C: Ancient bacterial cells came into existence after the formation of RNA. RNA was present even before cellular life forms with complex processes like cell division (which requires transfer of genetic information in a more organized way that evolved over time) were well - established.
• Option D: The Miller - Urey experiment and other similar studies suggest that the early Earth's atmosphere (containing gases like methane, ammonia, water vapor etc.) had the materials to form organic molecules like those in RNA. Lightning (as an energy source) could trigger chemical reactions to form these molecules.

Answer:

D. Earth’s early atmosphere contained the materials to form RNA, and lightning triggered the reaction.