Exam 4: Nucleic Acids and the Origin of Life

Scientists hypothesize that clay minerals and evaporating water at the edges of larger bodies of water were important in providing conditions that facilitated polymerization of building-block biomolecules into larger, more complex biomolecules.However, they think that these conditions were probably not sufficient to allow life to emerge.What additional development on early Earth likely occurred that allowed the necessary conditions for the eventual emergence of living cells? Why did this development move the origin of life forward when clay minerals and evaporating waters did not?

The copying of a DNA sequence to make an RNA sequence is called

Redi and Pasteur used experimentation to disprove the idea of spontaneous generation.However, scientists today do accept the idea of spontaneous generation.What explains this discrepancy?

Experiments have shown that DNA with a higher G + C content requires a higher temperature to disrupt its double helix than DNA with a higher A + T content.Which statement explains this observation?

The structural difference between nucleotides and nucleosides is a(n) _______.

A scientist has isolated a strand of DNA from a fungus and plans to characterize its properties.She has made a list of these properties in the table below. If the scientist wants to explore the evolutionary relationship between this fungus and another organism, she should use the _______ property of the DNA strand to carry out her analysis.

The ability of _______ is essential for the existence of ribozymes.

The process by which DNA makes an exact copy of itself is called _______.

Sketch a fatty acid, and show how a number of fatty acids can assemble into a bilayer membrane.

What evidence supports the possibility that life may have come from outside of Earth?

It is believed that cyanobacteria were among the first organisms to arise on Earth because they perform _______.

Suppose that scientists developed a protocell with a membrane that allowed all molecules to cross in or out of it.Would this membrane serve the function of a cell membrane?

Nucleotides are joined together in a single strand of DNA

Five descriptions of the probable conditions in different areas on primitive Earth are given.In which case is it most likely that complex molecules would have formed by polymerization of simpler molecules?

The process by which an RNA molecule is synthesized from a DNA template is called _______.

What is the sequence of the complementary strand of RNA made from the template DNA sequence below? (Note: Spaces between nucleotides have no purpose but to make the sequences easier to read.)

Many organic molecules are easily destroyed by oxygen in modern Earth's atmosphere.This finding

Refer to the figure below showing the Miller‒Urey experiment. The experiment, which was performed in the 1950s,

The four nitrogenous bases of RNA are abbreviated as

The enclosure of biologically relevant molecules within a membrane-bound protocell could have facilitated the evolution of metabolism and self-replication, which are hallmark properties of living cells.However, enclosure by a membrane would also create a challenge to the emerging cells, in that they would need some method to evolve that allowed nutrients and building-block molecules to pass from the environment into the protocell interior.Otherwise, the protocells would be doomed to die without this influx of matter.To explore this idea more, how could a scientist best design an experiment to investigate the possibility of such a property of protocells?