In some sheep, the presence of beard is produced by an autosomal allele that is dominant in males and recessive in females. A beard female is crossed with a homozygous beardless male. One of the resulting F1 females is crossed with a beardless male. What proportion of the male and female progeny from this cross will have beard in F2 generation?

#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 ________.

#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?