2) What characterizes a prokaryotic cell?
a. the lack of ribosomes
b. the lack of a membrane-enclosed nucleus
c. the presence of a nucleus with no DNA
d. the presence of mitochondria
e. having a cell wall without a cell membrane
3) Which of the following does NOT comprise a logical hierarchy of organization? a. family, order, class, phylum, kingdom
b. molecules, cells, tissues, organ systems, populations
c. organisms, populations, communities, biomes, biosphere
d. cells, tissues, organs, organ systems, organisms
e. molecules, atoms, organelles, tissues, systems
4) The scientific method usually begins with
a. formulating a testable hypothesis.
b. formulating a theory.
c. searching for relevant materials in the library.
d. collecting data.
e. conducting a controlled experiment.
5) Two species belonging to the same class must also belong to the same a. family. b. order. c. species. d. genus. e. phylum.
6) What do a fungus, a tree, and a human have in common?
a. They are all prokaryotic.
b. They are all composed of cells with nuclei.
c. They are all members of the same kingdom.
d. They are all members of the same class.
e. They all have cell walls.
1) The first genetic material was most likely
A) a protein.
B) a DNA oligonucleotide.
C) a DNA polymer.
D) a protein enzyme.
E) an RNA polymer.
2) Approximately how far does the fossil record extend back in time? A) 3,500,000,000 years
B) 3,500,000 years
C) 5,000,000,000,000 years
D) 6,000 years
E) 6,000,000 years
3) What are the banded rocks called that are believed to be the fossils of bacterial mat communities? A) stalagmites B) stromatolites C) stalactites D) coacervates E) strata 4) In their laboratory simulation of the early Earth, Miller and Urey observed the abiotic synthesis of A) coacervates. B) liposomes. C) microspheres. D) amino acids. E) DNA. 5) Why was the primitive atmosphere of Earth more conducive to the origin of life than the modern atmosphere of Earth?
A) The primitive atmosphere had a layer of ozone that shielded the first fragile cells. B) The primitive atmosphere removed electrons that impeded the formation of protobionts. C) The primitive atmosphere had more oxygen than the modern atmosphere, and thus it successfully sustained the first living organisms.
D) The primitive atmosphere had less free energy than the modern atmosphere, and thus newly formed organisms were less likely to be destroyed.
E) The primitive atmosphere was a reducing one that facilitated the formation of complex substances from simple molecules.
6) In what way were conditions on early Earth different from those on modern Earth? A) The early Earth had an oxidizing atmosphere.
B) The early atmosphere had significant quantities of CH4 and NH3. C) The early Earth was much cooler.
D) Less ultraviolet radiation penetrated the early atmosphere. E) The early Earth had no water.
7) Prokaryotes have ribosomes different from those of eukaryotes. Because of this, which of the following is TRUE?
A) Prokaryotes are able to use a much greater variety of molecules as food sources. B) It is believed that eukaryotes did not evolve from prokaryotes. C) Protein synthesis can occur at the same time as transcription in prokaryotes. D) Some selective antibiotics can block protein synthesis of bacteria without harming the eukaryotic host. E) Some antibiotics can block the formation of cross-links in the peptidoglycan walls of bacteria. 8) Of all the organisms, the prokaryotes have the greatest range of metabolic diversity. Which category of prokaryotes is currently the most important ecologically?
B) nitrogen fixers
C) obligate anaerobes
E) extreme halophiles
9) In the following list of major metabolic pathways, which one must have been the most recent to evolve? A) O2-producing photosynthesis
B) oxidative phosphorylation