1. The feature that most clearly separates eukaryotes from prokaryotes is the presence of _______ in eukaryotic cells. A) ribosomes B) oxidative phosphorylation C) DNA molecules -D) a nucleus
2. Cytoplasmic organelles are
- A) absent in prokaryotic cells; present in eukaryotic cells. B) present in both prokaryotic and eukaryotic cells. C) present in prokaryotic cells; absent in eukaryotic cells. D) absent in both prokaryotic and eukaryotic cells.
3. Eukaryotic chromosomes contain _______ DNA molecules. A) single linear B) single circular -C) multiple linear D) multiple circular
4. Which energy-producing process is thought to have come first during cellular evolution? A) Photosynthesis -B) Glycolysis C) Oxidative phosphorylation D) All originated at the same time
5. At the time life arose on Earth, Earth's atmosphere contained all but which of the following? A) H2 B) N2 -C) O2 D) H2S
6. Stanley Miller's experiment that applied electric sparks to a reducing atmosphere of methane, ammonia, water, and hydrogen showed that under these conditions, A) nucleotides can form. -B) amino acids can form. C) amino acids can polymerize into polypeptides. D) nucleotides can polymerize into nucleic acids.
7. Organisms that evolved the ability to use H2O as a donor of electrons and hydrogen for the photosynthesis conversion of CO2 to organic compounds radically changed Earth by producing A) sugar. B) cellulose. -C) O2. D) H2.
8. RNA is believed to have been the initial genetic system because it can A) form a stable double helix with a complementary nucleic acid strand. -B) catalyze the polymerization of nucleotides into another RNA strand. C) form ribosomes. D) transfer amino acids to ribosomes.
9. The initial importance of a