An ideal α-helix has a pitch of 0.54 nm and a rise of 0.15 nm. What is the length along the helix axis for a segment of an ideal α-helix that contains 30 amino acids?

#Question id: 8712

#Unit 9. Diversity of Life Forms

The lakes of northern Minnesota are home to many similar species of damselflies of the genus Enallagma. These species have apparently undergone speciation from ancestral stock since the last glacial retreat about 10 thousand years ago. Sequencing which of the following would probably be most useful in sorting out evolutionary relationships among these closely related species?

#Question id: 8713

#Unit 9. Diversity of Life Forms

Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of sequence homology? Dogs and wolves ________.

#Question id: 8714

#Unit 9. Diversity of Life Forms

The reason that paralogous genes can diverge from each other within the same gene pool, whereas orthologous genes diverge only after gene pools are isolated from each other, is that ________.

#Question id: 8715

#Unit 9. Diversity of Life Forms

Which of the following items is most likely to form a simple linear relationship with the number of gene-duplication events, when placed as the label on the vertical axis of the following graph?

#Question id: 8716

#Unit 9. Diversity of Life Forms

The most important feature that permits a gene to act as a molecular clock is ________.

#Question id: 8717

#Unit 9. Diversity of Life Forms

Molecular clocks are more reliable when ________.