11) Experiments with enzymes made of RNA support which origin-of-life model?

A) Miller model

B) replicator-first model

C) metabolism-first model

D) DNA world model

12) What argument do scientists who support the metabolism-first model use to dispute the replicator-first model?

A) The replicator nucleic acid molecule would be too large and complex.

B) DNA cannot replicate without the help of proteins.

C) RNA can only be used to make proteins, not other nucleic acids.

D) Replicators cannot exist without metabolism.

13) Which of these gases was absent in the early Earth atmosphere at the time life first appeared?

A) nitrogen

B) water vapor

C) carbon dioxide

D) oxygen

14) To be a successful cell evolutionarily, the earliest cells had to:

A) reproduce.

B) consume oxygen.

C) photosynthesize.

D) have mitochondria.

15) You discover a single-celled organism that does not have a nucleus, and you also notice that the culture is producing methane. In which group would you place this organism?

A) Domain Bacteria

B) Domain Archaea

C) Domain Eukarya

D) Kingdom Protista

16) A major difference between cells of organisms in Domain Eukarya and the cells of those in Domains Bacteria and Archaea is that:

A) Domain Eukarya organisms can only live in acid environments.

B) Domain Bacteria and Archaea cells can only live in acid environments.

C) Domain Bacteria and Archaea cells have a nucleus and Domain Eukarya cells do not.

D) cells of Domain Eukarya have a nucleus and Domains Bacteria and Archaea do not.

17) Organisms from which kingdom or domain were the first photosynthesizers?

A) Protista

B) Plantae

C) Bacteria

D) Archaea

18) Before the development of photosynthesis and as ancient cells became crowded, there was probably a major competition for:

A) enzymes.

B) water.

C) organic molecules.

D) oxygen gas.

19) Which of the following statements best describes the history of life on Earth?

A) The Earth was lifeless far longer than it had living things.

B) The Earth had multicellular life-forms for most of its history.

C) The Earth had single-celled life-forms for most of its history.

D) The Earth had photosynthetic organisms about 100 million years after it formed.

20) A major event in the Precambrian era responsible for dramatically increasing organic material on Earth was:

A) evolution of mitochondria.

B) evolution of photosynthesis.

C) deposition of carbon in rocks.

D) leaching of sulfur into the oceans.