For many years, biologists felt that the highest level of classification of living organisms was the five kingdoms. Recently, some biologists have proposed that the hierarchical classification of organisms start with three domains, the Bacteria, the Archaea, and the Eucarya. Explain the reasoning behind this proposal and why the Bacteria and the Archaea should be in separate domains even though
their members are all prokaryotes.
What will be an ideal response?
Recent RNA analysis and other molecular data have suggested that the Bacteria are very different from the Archaea even though members in each group are prokaryotes. The analysis has also shown that the Archaea are more closely related to the Eucarya than they are to the Bacteria.
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The myometrium is
a. the lining of the uterus. b. the lining of the vagina. c. the tissue that covers an ovary. d. smooth muscle in the wall of the uterus. e. the lining of the oviducts.
Most genetic counselors
A. have an M.D. and/or Ph.D. degree. B. are individuals who have previously sought counseling themselves. C. are trained in biology and psychology, but are unfamiliar with lab and clinical procedures. D. work in individual private counseling offices. E. have none of these traits.
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Figure 34.4A
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Use the posterior pituitary function illustration above to answer the following question.
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Signals that stimulate the release of hormone molecules are carried along the component indicated by the letter ____.
A. A B. B C. C D. D E. E
Which phenomenon is a likely consequence of thinning of the ozone layer?
A) more occurrences of skin cancer B) greater escape of heat from Earth C) global warming D) smaller flying insect populations