The prokaryotic flagellum has three parts in the order from cytoplasm to external environment:
A. filament, hook, basal body
B. filament, basal body, hook
C. basal body, hook, filament
D. hook, basal body, filament
E. basal body, filament, hook
Answer: C. basal body, hook, filament
You might also like to view...
Why are nucleoside analogs active only against replicating viruses?
A. These drugs can only be taken up by cells that are infected by viruses. They are shut out from non-infected cells. This makes them effective only against cells where viruses are replicating. B. Each of these drugs is specifically activated by enzymes produced by the viruses. The viruses will only produce these enzymes when they are replicating, so the drugs can only become activated when these processes are occurring. C. Nucleoside analogs work by directly inhibiting the activity of nucleic acid polymerases. If the virus isn't actively replicating, there's no DNA/RNA polymerase active for the drug to inhibit, so the drug cannot work. D. Nucleoside analogs work by being incorporated into growing strands of DNA/RNA. This indirectly shuts down further extension of these chains. However, new strands of viral DNA/RNA are only being created when the virus is replicating. As such, these drugs can only work when the virus is actively replicating as well.
Which one of the following would result in a decrease in cardiac output?
A) increased heart rate B) decreased stroke volume C) exercise D) strong emotions E) activation of the sympathetic nervous system
The basic chemistry of DNA transposition is a:
A. kinase reaction. B. phosphoryl transfer reaction. C. phosphatase reaction. D. ubiquitination reaction. E. methylation reaction.
Which circumstance violates the conditions of the Hardy—Weinberg model?
a. the population is infinitely large b. the population is closed to migration from other populations c. no mutations are occurring d. all genotypes in the population survive and reproduce equally well e. nonrandom mating with respect to genotypes occurs between individuals