#Question id: 8717
#Unit 9. Diversity of Life Forms
Molecular clocks are more reliable when ________.
#Question id: 8718
#Unit 9. Diversity of Life Forms
Which of the following would, if it had acted upon a gene, prevent this gene from acting as a reliable molecular clock?
#Question id: 8720
#Unit 9. Diversity of Life Forms
The question refers to the following table, which compares the percent sequence homology of four different parts (two introns and two exons) of a gene that is found in five different eukaryotic species. Each part is numbered to indicate its distance from the promoter (for example, Intron I is the one closest to the promoter). The data reported for species A were obtained by comparing DNA from one member of species A to another member of species A.
Which of these four gene parts should allow the construction of the most accurate phylogenetic tree, assuming that this is the only part of the gene that has acted as a reliable molecular clock?
#Question id: 8721
#Unit 9. Diversity of Life Forms
Based on cladistics, which eukaryotic kingdom is polyphyletic and, therefore, unacceptable?
#Question id: 8773
#Unit 9. Diversity of Life Forms
Which eukaryotic kingdom includes members that are the result of endosymbioses that included an ancient aerobic bacterium and an ancient cyanobacterium?
#Question id: 8774
#Unit 9. Diversity of Life Forms
A large proportion of archaeans are extremophiles, so called because they inhabit extreme environments with high acidity, salinity, and/or temperature. Such environments are thought to have been much more common on primitive Earth. Thus, modern extremophiles survive only in places that their ancestors became adapted to long ago. Which of the following is, consequently, a valid statement about modern extremophiles, assuming that their habitats have remained relatively unchanged?