Question 1

Some viruses never use DNA to carry out protein synthesis and have only RNA as their genetic material. This would lend evidence to which theory?

Accepted Answer

The fact that some viruses only use RNA as their genetic material suggests that RNA may have come before DNA in the evolution of life on Earth, supporting the RNA-first hypothesis.

Question 2

Who was the individual who proposed the hypothesis of continental drift during the 1920s?

Accepted Answer

Alfred Wegener proposed the hypothesis of continental drift during the 1920s.

Question 3

Which statement is NOT true about the RNA-first hypothesis?

Accepted Answer

The RNA-first hypothesis does not suggest that DNA came after RNA and proteins in the development of the first cells. Instead, it proposes that RNA played a central role in the origin of life and that DNA and proteins evolved later.

Question 4

If the hypothesis that protocells were based on an "RNA world" is correct, what would be necessary to shift to a "DNA world"?

Accepted Answer

The transition from an "RNA world" to a "DNA world" would require several key developments: an enzyme or reaction to modify ribose to deoxyribose (A), reverse transcription mechanisms to convert RNA sequences into DNA (B), enzymes capable of replicating DNA (C), and mechanisms to transcribe DNA back into RNA for protein synthesis (D). All these components are essential for the establishment and functioning of a DNA-based system of genetic information storage and expression.

Question 5

It is likely that the protocell was

Accepted Answer

It is difficult to determine with certainty what type of nutrition the protocell had, but it is most likely either heterotrophic (obtaining nutrients from organic compounds) or chemoautotrophic (obtaining energy from inorganic compounds such as hydrogen sulfide and using carbon dioxide as a carbon source). Photoautotrophic (using light energy to produce organic compounds) and decomposer (breaking down complex organic compounds) are less likely as they would require specific environmental conditions that may not have been present in the early Earth.

Question 6

Biological evolution differs from chemical evolution in that it would have been possible only after the development of

Accepted Answer

Biological evolution involves the mutation and selection of living organisms, which requires the existence of true cells. Chemical evolution, on the other hand, involves the synthesis of organic molecules from inorganic precursors, which can occur without cells. While the development of nucleic acids, enzymes, and metabolic pathways was certainly important for biological evolution, it ultimately depended on the existence of cells.

Question 7

Which of the following forms of energy was NOT involved in the production of large organic molecules in the primitive reducing atmosphere?

Accepted Answer

Sound energy was not involved in the production of large organic molecules in the primitive reducing atmosphere. The other options (radioactivity, electrical energy, heat, radiation from the sun) have all been proposed as sources of energy for the chemical reactions that led to the formation of organic molecules.

Question 8

The Greek terms for "small" and "ball" are the root words for

Accepted Answer

The Greek term for "small" is "micro," and the term for "ball" is "sphere." Therefore, the root words for "microsphere" come from these Greek terms. The other answer choices are not made up of these root words.

Question 9

The first known multicellular organisms evolved approximately how many years ago?

Accepted Answer

The answer of The first known multicellular organisms evolved approximately...

Question 10

The term "reducing atmosphere" for the early Earth means that the atmosphere

Accepted Answer

A reducing atmosphere is one that contains little or no free oxygen, which was likely the case on the early Earth before the emergence of photosynthetic organisms. This means that instead of oxygen, the atmosphere was likely rich in other gases such as methane, ammonia, and water vapor.

Question 11

___________ proposed that clay may have served as the site of polymerization of monomers to produce both nucleic acids and proteins at the same time.

Accepted Answer

Graham Cairns-Smith proposed the clay theory, which suggests that clay minerals acted as a template for the formation of organic molecules, including the polymerization of nucleic acids and proteins.

Question 12

________ discovered that a variety of amino acids and organic acids could be produced in the laboratory in a reducing atmosphere with electrical sparks.

Accepted Answer

This statement refers to the Miller-Urey experiment, which was conducted by Stanley Miller and Harold Urey in 1952.

Question 13

Which of the following time periods contains the others?

Accepted Answer

Mesozoic is the only time period that contains all three of the other options (Cretaceous, Triassic, and Jurassic) within it.

Question 14

The first person who proposed that small organic molecules could have arisen by chemical evolution was

Accepted Answer

Aleksander Oparin was the first person to propose the theory of chemical evolution, which postulated that life originated from non-living organic molecules through a series of chemical reactions in Earth's early environment.

Question 15

List in order of appearance the four stages of the origin of life and explain what was necessary to occur in order for life to have evolved in this fashion.

Accepted Answer

The answer of List in order of appearance the four...

Question 16

Which of the following molecules are believed to have been absent from the primitive reducing atmosphere?

Accepted Answer

Oxygen (O2) is believed to have been absent from the primitive reducing atmosphere.

Question 17

Which piece of evidence would best support the theory of continental drift?

Accepted Answer

The presence of similar mammalian fauna on continents that were once part of the supercontinent Gondwana supports the theory of continental drift, as it suggests these continents were once connected.

Question 18

The fact that a nucleic acid is a very complicated molecule suggests that

Accepted Answer

The complexity of a nucleic acid molecule suggests that it could not have arisen on its own by chance and therefore required enzymes to guide the synthesis of nucleotides and then nucleic acids. This supports the RNA world hypothesis, which suggests that RNA was the first self-replicating molecule, but required enzymes for its synthesis.

Question 19

Which statement is NOT true about a protocell?

Accepted Answer

It is not certain that a protocell would have contained DNA as its genetic material. RNA may have been the first genetic material in early cells, or there may have been other types of genetic material that are no longer present in modern cells.

Question 20

Which of the following mass extinction is correctly matched with the date of the extinction?

Accepted Answer

The Cretaceous mass extinction is correctly matched with the date of 65.5 million years ago. The other options are close but not exact: the Silurian extinction occurred 443.8 million years ago, the Devonian extinction occurred 359.2 million years ago, and the Triassic extinction occurred 200 million years ago.

Quiz 18: Origin and History of Life