Exam 4: Nucleic Acids and the Origin of Life

Some trace metals such as molybdenum and rhenium are soluble in oxygenated water.These rare metals first appeared in sedimentary rocks on Earth 2.5 billion years ago, where previously they occurred as chemical compounds in minerals.The appearance of these metals at this time indicates that

Miller and Urey set up an experimental "atmosphere" composed of gases thought to be present in Earth's early atmosphere.They simulated lightning with the application of electricity and looked for the monomers used to build living organisms.Subsequent experiments using additional gases that probably were present in the early Earth environment resulted in a more diverse list of organic products.Which compounds were absent from the products of Miller and Urey's experiments?

What evidence lent strong support to J.William Schopf's hypothesis that the 3.5-billion-year-old fossil he discovered in Australia was that of ancient cells?

Scientists hypothesize that nonliving protocells developed as a precursor to living cells.Which statement can best be used as evidence to support this hypothesis?

Which statement about the addition of a nucleotide onto a growing nucleic acid is true?

All of the following bases are found in DNA except

Complementary base pairing between nucleotides makes which process possible?

Chemical reaction rates vary depending on the concentrations of reactants.In which primitive Earth environment would conditions have shifted reactant concentrations to favor increased polymerization of monomers?

Miller and Urey's 1954 hot chemistry experiment was based on the assumption that Earth's early atmosphere contained water (H₂O) vapor, methane, hydrogen, and ammonia.Subsequent research showed that volcanoes released carbon dioxide (CO₂), hydrogen sulfide (H₂S), and sulfur dioxide (SO₂) around 4 billion years ago.In response to this evidence, scientists concluded that

With a few exceptions, each human cell contains DNA in its nucleus.Which statement about any cell containing DNA is true?

Which factor contributes to the strength of the intermolecular interaction between two DNA strands in a double helix?

Laboratory experiments with pure samples of either the d- or l-isomer of the amino acid aspartic acid show that these samples slowly change to an equilibrium mixture of both optical isomers.The rate of change is extremely slow, requiring a few million years to billions of years to complete, depending on temperature and availability of water.If scientists wanted to locate amino acids as evidence of past life on the planet Mars, what region would be best to study, given that any life on Mars may have gone extinct early in its history?

Refer to the figure below illustrating Louis Pasteur's experiment on spontaneous generation. Why was the neck broken on one flask but not the other?

Refer to the figure below showing the Miller‒Urey experiment. Research conducted later than the Miller‒Urey experiment showed that volcanic activity 4 billion years ago injected other gases, such as SO₂, into Earth's early environment.This information led to the conclusion that

Which statement about the "RNA world" model is true?

According to the chemical evolution theory of the origin of life, which statement is true?

Redi performed experiments using raw meat and _______ to disprove the idea of spontaneous generation.

The diversity found among DNA molecules is due to the sequence of _______.

Refer to the figure below showing two strands of DNA. How many hydrogen bonds would there be in a DNA sequence of ten base pairs in which there are five A-T and five C-G pairs?

Which is evidence that supports the hypothesis that DNA could have evolved from RNA?