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.) ![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.) - Which of the following changes would a modern systematist be most likely to make after learning of the results of the rRNA analyses? A) continue to keep subgroups A-D as members of the species G. intestinalis B) break the species G. intestinalis into four separate species, A, B, C, and D C) combine subgroup D and G. microti into one species D) combine all the subgroups of G. intestinalis (A-D) and G. microti to make one species](https://d2lvgg3v3hfg70.cloudfront.net/TB6149/11eaa959_8631_1b3a_84bc_fbe1c4fdcf18_TB6149_00.jpg)
-
Which of the following changes would a modern systematist be most likely to make after learning of the results of the rRNA analyses?
Definitions:
Link Method
A memory technique where you visualize items to be remembered in a way that they are linked together by a story or association.
Method of Loci
A mnemonic strategy of memory enhancement which uses visualizations with the use of spatial memory, familiar information about one's environment, to quickly and efficiently recall information.
Acrostic Method
A mnemonic device that uses the first letters of words in a list to form a sentence or phrase, aiding in memory retention.
Memory Accuracy
The degree to which remembered details match the actual events that occurred.
Q9: Fossilised stromatolites<br>A) formed around deep-sea vents.<br>B) resemble
Q23: The genome of modern chloroplasts is roughly
Q31: What does the biological species concept use
Q34: Which factor most likely caused animals and
Q53: Which two genera have members that can
Q54: Breeuwer et al. (2008) measured the effect
Q60: The common ancestor of the protostomes had
Q63: Imagine that after generation 20,000, the experimental
Q65: Among the newly discovered small noncoding RNAs,
Q76: In onions (Allium), cells of the sporophyte