Use the Following Information to Answer the Question

question 7

Multiple Choice

Use the following information to answer the question.
Giardia intestinalis can cause disease in several different mammalian species, including humans. Giardia organisms (G. intestinalis) that infect humans are similar morphologically to those that infect other mammals, thus they have been considered a single species. However, G. intestinalis has been divided into different subgroups based on their host and a few other characteristics.
In 1999, a DNA sequence comparison study tested the hypothesis that these subgroups actually constitute different species. The following phylogenetic tree was constructed from the sequence comparison of rRNA from several subgroups of G. intestinalis and a few other morphologically distinct species of Giardia. The researchers concluded that the subgroups of Giardia are sufficiently different from one another genetically that they could be considered different species. (T. Monis, et al. 1999. Molecular systematics of the parasitic protozoan Giardia intestinalis. Mol. Biol. Evol. 16[9]:1135-44.)

According to the phylogenetic tree in the figure above, G. intestinalis constitutes a ________ group.

• A) analytic
• B) monophyletic
• C) polyphyletic
• D) paraphyletic

Recognize the importance of environmental factors and community infrastructure in disease prevention.

Understand the historical development of public health initiatives and their impact on community health.

Analyze the role of government and non-governmental organizations in the advancement of public health.

Identify key figures and their contributions to public health and nursing.

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Definitions:

Controlling Account

A general ledger account that summarizes the balances of a set of subsidiary accounts, facilitating overall management.