Which statement is true?
a. Once a vaccine for a virus has been developed, further vaccine development is unnecessary.
b. Antiviral drug therapy is safer than vaccination because there is no risk of tissue damage involved.
c. Viruses nearly eliminated by mass immunization campaigns can still cause epidemics.
d. Vaccinations contain dangerous quantities of chemicals such as mercury and formaldehyde.
c. Viruses nearly eliminated by mass immunization campaigns can still cause epidemics.
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The presence of a lophophore in a newly discovered species would suggest that the species _____
A) has an exoskeleton B) grows by shedding its external covering C) is more closely related to an arthropod than a mollusk D) is motile E) is a suspension feeder
The energy required for plants to perform photosynthesis comes from which of the following?
a. mechanical energy b. light energy c. chemical energy d. kinetic energy
Four of the five answers listed below concern
cells with two chromosome sets. Select the EXCEPTION.
a. zygote b. somatic cell c. spore d. diploid e. sporophyte
The body of a fungus has several characteristics. One of these is their hyphae, long chains of cells. Which of the following statements best describes the nature of septa and cross walls?
A. Septa form cross walls between the long chains of cells that make up hyphae. B. Septa of the cross walls are formed on the outside of fungal cells and give the fungal body more rigidity. C. Spores of fungi that are formed within reproductive structures have cross walls separated by septa. D. The cross wall within the nuclear membrane of every fungal body forms septa. E. Cross walls are responsible for the formation of spindle plaques within the hyphae after the septa are produced.