Exam 26: Phylogeny and the Tree of Life

Use the following figure and description to answer the question. Humans, chimpanzees, gorillas, and orangutans are members of a clade called the great apes, which shared a common ancestor about 15 million years ago. Gibbons and siamangs comprise a clade called the lesser apes. Tree-branch lengths indicate elapsed time. Assuming chimps and gorillas are humans' closest relatives, removing humans from the great ape clade and placing them in a different clade has the effect of making the phylogenetic tree of the great apes ________.

Use the following information to answer the question. Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "chromatophores." The chromatophores are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants. A crucial photosynthetic gene of the cyanobacterium that gave rise to the chromatophore is called psaE. This gene is present in the nuclear genome of the cercozoan, but is not in the genome of the chromatophore. This is evidence of ________.

Use the following information to answer the question. Applying the principle of parsimony to the trait "ability to fly," which of the two phylogenetic trees is better?

The following question refers to this phylogenetic tree, depicting the origins of life and the three domains. Horizontal lines indicate instances of gene or genome transfer. A possible phylogenetic tree for the three domains of life. Which of these processes can be included among those responsible for the horizontal components of the figure?

The following question refers to the following phylogenetic trees. Which tree shows the greatest evolutionary distance between chytrids and ascomycetes?

Use the figure to answer the following question. Which extinct species should be the best candidate to serve as the outgroup for the clade whose common ancestor occurs at position 2 in the figure?

Based on cladistics, which eukaryotic kingdom is polyphyletic and, therefore, unacceptable?

Use the following information to answer the question. Which of the following trees, if any, depicts the same relationship among species as shown above?

Imagine that a phylogeny was developed for a group of mammals based on bone structure. Which of the following statements would be a reasonable prediction about a phylogeny for the same group of species based on similarities and differences in the structure of a particular enzyme?

What kind of evidence has recently made it necessary to assign the prokaryotes to either of two different domains, rather than assigning all prokaryotes to the same kingdom?

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. % Sequence Homology Species Intron I Exon I Intron VI Exon V A 100\% 100\% 100\% 100\% B 98\% 99\% 82\% 96\% D 98\% 99\% 89\% 96\% E 99\% 99\% 92\% 97\% 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?

Eukaryotes that are not closely related and that do not share many anatomical similarities can still be placed together on the same phylogenetic tree by comparing their ________.

The common ancestors of birds and mammals were very early (stem)reptiles, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The four-chambered hearts of birds and mammals are best described as ________.

Use the following information to answer the question. Refer to the figure. Which of the following forms a monophyletic group?

A phylogenetic tree constructed using sequence differences in mitochondrial DNA would be most valid for discerning the evolutionary relatedness of ________.