The feature that most clearly distinguishes eukaryotes from prokaryotes is the presence of
.......... in eukaryotic cells.
A. oxidative phosphorylation
B. RNA molecules
C. ribosomes
D. a nucleus - AnswersD. a nucleus
Cytoplasmic organelles are
a. present in prokaryotic cells and absent in eukaryotic cells.
b. present in both prokaryotic and eukaryotic cells.
c. absent in both prokaryotic and eukaryotic cells.
d. absent in prokaryotic cells and present in eukaryotic cells. - Answersd. absent in prokaryotic
cells and present in eukaryotic cells.
The eukaryotic nucleus contains .......... DNA molecule(s).
a. a single linear
b. multiple linear
c. multiple circular
d. a single circular - Answersb. multiple linear
Stanley Miller applied electric sparks to a reducing atmosphere of methane, ammonia, water,
and hydrogen, and the resulting products showed that under these conditions,
a. amino acids can form.
b. nucleotides can polymerize into nucleic acids.
c. amino acids can polymerize into polypeptides.
d. nucleotides can form. - Answersa. amino acids can form.
Which energy-producing process is thought to have come first during cellular evolution?
Oxidative phosphorylation
Glycolysis
, Proteolysis
Photosynthesis - AnswersGlycolysis
At the time life arose on Earth, Earth's atmosphere contained abundant amounts of all of the
following except
a. N2.
b. O2.
c. H2S.
d. H2. - Answersb.. O2.
CO2 to organic compounds radically changed Earth by producing
a. cellulose.
b. O2.
c. H2.
d. sugar. - Answersb. O2.
RNA is believed to have been the initial genetic system because it can
a. form ribosomes.
b. form a stable double helix with a complementary nucleic acid strand.
c. transfer amino acids to ribosomes.
d. catalyze the polymerization of nucleotides into another RNA strand. - Answersd. catalyze the
polymerization of nucleotides into another RNA strand.
The initial importance of a membrane enclosing self-replicating RNA molecules and associated
proteins was that it
a. maintained these molecules as a unit capable of reproduction and evolution.
b. provided sites for proteins to function.
c. transported materials in and out of the compartment.
d. kept other molecules out of the compartment. - Answersa. maintained these molecules as a
unit capable of reproduction and evolution.
The bacterial genome is located in a portion of the cell called the