Discuss the advantages and disadvantages associated with the production of ammonia, urea, and uric acid. What will be an ideal response?
Ammonia is the direct product of deamination and thus is energetically inexpensive; although
it is water soluble, it is highly toxic. The synthesis of both urea and uric acid require an
additional energy input by cells, but both are nontoxic. Uric acid is insoluble in water and
thus can be excreted as a paste, reducing water loss; it can also be safely stored in the eggs of
birds and reptiles. Because urea is highly soluble, considerable water must be used to excrete
it, and consequently the organism risks desiccation.
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Methylene blue in EMB agar is selective for
A) gram-positives. B) gram-negatives. C) viral plaques. D) both gram-positives and gram-negatives.
The difference in the appearance of the male and the female of the same species is called
a. polymorphism. b. sexual dimorphism. c. the dioecious condition. d. sexual selection. e. a primary sexual characteristic.
Eugenic laws were enacted in an attempt to
A. prevent some individuals from reproducing. B. eliminate "bad genes" from the human population. C. improve the human gene pool. D. All of these answers are true.
A coral species that currently inhabits a single reef off the coast of Indonesia would be considered
A. endemic. B. a transitional form. C. exotic. D. vestigial.