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
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
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.
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 membrane enclosing self-replicating RNA molecules and associated proteins was that a membrane -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.
10. Eukaryotic cell nuclei contain genes that are
A) primarily of eukaryotic origin.
B) primarily of archaebacterial origin.
-C) partly archaebacterial and partly eubacterial in origin. D) derived from neither archaebacterial nor eubacterial cells.
11. Organelles such as mitochondria and chloroplasts are thought to have originated in eukaryotic cells via a process called A) phagocytosis.
D) autogenous formation.
12. Mitochondria and chloroplasts resemble bacteria in that they A) have their own DNA.
B) have their own ribosomes.
C) reproduce by simple division into two.
-D) All of the above
13. The bacterial genome is located in a portion of the cell called the A) nucleus.
14. Which of the following is a colonial organism closely related to the evolutionary precursors of present-day plants? A) Euglena
B) Dictyostelium discoideum
D) Arabidopsis thaliana
15. The human body is composed of more than _______ different cells. A) 100
16. Similarities in basic cellular mechanisms indicate that all present-day cells on Earth descended from a single primordial ancestor. A) True
17. Photosynthesis first evolved in the green algae.
18. Most of the genes of the bacterial symbionts that evolved into mitochondria are now found in the nucleus. A) True
19. Eukaryotes evolved approximately 900 million years ago. A) True
20. Higher plants and higher animals are similar in that they contain about the same...