Exam 4: Nucleic Acids and the Origin of Life

Refer to the figure below, showing how fatty acids self-assemble to form a bilayer membrane in water. The arrow indicates the polar head of a(n) fatty acid, which is _______, a term meaning water-loving.This portion of the fatty acid interacts with water molecules.

Which gas was a component of Earth's early atmosphere?

Information flows from _______ only during cell reproduction.

J.William Schopf discovered a fossil cyanobacterium in Australian rocks that are 3.5 billion years old.The specific ratio of carbon isotopes (¹³C:¹²C) in the fossil indicated that the organism

Fatty acids have hydrophilic heads and hydrophobic tails.This allows them to

Which statement concerning chemical reactions and catalysts is true?

Unlike pyrimidines, purines have a _______-ring structure.

One of the first steps leading to a cell that could reproduce may have been the formation of protocells.What characteristics may have allowed protocells to be the precursors to the living cell?

J.William Schopf found fossils in ancient Australian rocks with an internal structure unlikely to occur through abiotic processes.Additional evidence that these were fossil cyanobacteria includes

Which statement concerning genetic information in most cells is true?

Which was absent in the products analyzed at the conclusion of the Miller-Urey experiments?

Nucleotides are composed of

The French scientist Louis Pasteur showed that, under Earth's present conditions,

Which statement about the addition of new nucleotides onto a nucleic acid is true?

The cold chemistry experiment of Miller showed prebiotic synthesis in test tubes containing ammonia gas, water vapor, and cyanide (HCN) cooled to -78^oC.This is the temperature of the ice that covers Europa, one of Jupiter's moons.This result is most consistent with which statement?

What type of bond connects two complementary nucleotides?

In Stanley Miller's long-term cold chemistry experiment concerning prebiotic synthesis, test tubes containing ammonia gas, water vapor, and cyanide (HCN) were cooled to -78°C.When they were opened after 27 years, they contained amino acids and nucleotide bases.This result was interpreted to mean that

The complete set of DNA in a living organism is called its _______.

What is the significance of modeling experiments performed by Miller and Urey, and what are the limitations of such experiments?

A nucleotide contains a pentose sugar, a phosphate group, and a(n)