In chemical synapses that involve a so-called second messenger, typically a G-protein linked to the postsynaptic receptor is activated when neurotransmitter binds to that receptor. Which of the following represents an activity performed by the activated second messenger?

#Question id: 9611

#Unit 9. Diversity of Life Forms

If, someday, an archaean cell is discovered whose SSU-rRNA sequence is more similar to that of humans than the sequence of mouse SSU-rRNA is to that of humans, the best explanation for this apparent discrepancy would be

#Question id: 9609

#Unit 9. Diversity of Life Forms

Dozens of potato varieties exist, differing from each other in potato-tuber size, skin color, flesh color, and shape. One might construct a classification of potatoes based on these morphological traits. Which of these criticisms of such a classification scheme is most likely to come from an adherent of the phylocode method of classification?

#Question id: 9608

#Unit 9. Diversity of Life Forms

Darwin analogized the effects of evolution as the above-ground portion of a many-branched tree, with extant species being the tips of the twigs. The common ancestor of two species is most analogous to which anatomical tree part?

#Question id: 9607

#Unit 9. Diversity of Life Forms

The common housefly belongs to all of the following taxa. Assuming you had access to textbooks or other scientific literature, knowing which of the following should provide you with the most specific information about the common housefly?

#Question id: 9604

#Unit 9. Diversity of Life Forms

The various taxonomic levels (viz, genera, classes, etc.) of the hierarchical classification system differ from each other on the basis of

#Question id: 9601

#Unit 9. Diversity of Life Forms

The relative lengths of the frog and mouse branches in the phylogenetic tree indicate that