Exam 4: Nucleic Acids and the Origin of Life

Refer to the figure below.Part A shows the structure of one of the RNA molecules in a ribosome.Part B shows how the progress of protein synthesis is affected when one of the hydroxyl groups in an adenine nucleotide (adenine 2451 in part A) in this RNA molecule is chemically altered. A ribosome functions as the site of protein synthesis in modern cells.Structurally, a ribosome is composed of several protein and RNA molecules that combine in a complex.Based on the information shown, which statement accurately provides evidence for the "RNA world" hypothesis of the origin of life on Earth?

It has been hypothesized that early life consisted of an "RNA world"-a world before DNA.Which statement does not support this hypothesis?

Closely related living species should have (more/less) _______ similar DNA sequences than species that are more distantly related.

Suppose you obtain four different samples of nucleic acids.You analyze the nitrogenous base composition of each one and get the results in the table below (the numbers indicate percentage of each nitrogenous base in the samples). Which of these nucleic acids is/are single-stranded RNA?

What is the nucleotide sequence of the complementary strand of the following DNA molecule: AATGCGA?

Evidence to support the possibility that life may have come from outside Earth includes the meteorites that contain _______, the basic monomers of proteins.

Which pair of characteristics of RNA enables it to take on different shapes that allow it to bind to diverse substances in solution and speed up chemical reactions?

The two strands of a DNA double helix can be separated with relative ease because

Which statement concerning spontaneous generation of life is true?

Unlike DNA, RNA contains

Refer to the figure below. What belongs in the empty box?

Refer to the table below, representing two experiments conducted by Stanley Miller to simulate early Earth conditions. A comparison of the two experiments highlights a major limitation in designing and running these types of experiments so that a valid conclusion may be drawn.Which statement describes such a limitation?

Which gas is not thought to have been added to the atmosphere by extensive volcanic eruptions early in Earth's history?

ATP is hydrolyzed to ADP and inorganic phosphate during muscle contraction.Explain how this represents an example of a nucleotide functioning in a way other than for the purpose of information processing.

Refer to the figure below. Which written description is appropriately matched to the figure?

Evidence points to the formation of Earth 4.6 billion years ago and the first signs of life arising on Earth 4.0 billion years ago.That means that there was a 600-million-year period during which certain conditions could have developed to the point that life could arise.A limitation of simulation experiments, such as those conducted by Miller and Urey, is that they cannot simulate the extremely long time period during which Earth existed in a _______ state.

Which statement is true concerning ATP?

In laboratory experiments simulating conditions thought to be present on early Earth, small biologically relevant molecules, including amino acids, simple sugars, and fatty acids, have been synthesized from simple precursors.However, these experiments have not yielded larger polymers of these small biomolecules.If you were to set up a simulation experiment to study the polymerization of small biomolecules, which condition or addition would you suggest testing?

Refer to the figure below showing a cutaway view of a protocell, a structure representing a possible intermediate in the evolution of living cells from nonliving molecular building blocks. The structure of a protocell has several effects on the molecules present in its interior.One effect of the protocell structure that could have accelerated the evolution process was

A prerequisite for life as we know it on Earth or any other planet is