Life: The Science of Biology, Ninth Edition Sadava • Hillis • Heller • Berenbaum CH 20 Development and Evolutionary Change

1. Which of the following statements about the gene eyeless is true? a. It encodes a transcription factor. b. It is found in Drosophila. c. Pax6 is the equivalent gene in mice. d. All of the above e. None of the above Answer: d Textbook Reference: 20.0 The eyes have it Page: 426 Bloom’s Category: 1. Remembering 2. Flies have eyes, while mammals have eyes. a. cameralike; compound b. cameralike; binocular c. compound; cameralike d. compound; heterochronic e. simple; compound Answer: c Textbook Reference: 20.0 The eyes have it Page: 426 Bloom’s Category: 1. Remembering 3. Which of the following conclusions emerged from the studies performed by Walter Gehring and his colleagues on Drosophila eyes? a. The DNA sequence of the Pax6 gene of mice and the eyeless gene of flies is similar. b. The Pax6 gene of mice can substitute for the eyeless gene in the process of eye development in flies. c. Fly eyes look like mammalian eyes. d. Both a and b e. Both b and c Answer: d Textbook Reference: 20.0 The eyes have it Page: 426 Bloom’s Category: 2. Understanding 4. Which of the following techniques or tools was instrumental in the studies performed by Gehring and his colleagues demonstrating that eyeless is a transcription factor involved in eye development? a. Comparison of DNA sequences by means of a database search b. Recombinant DNA constructs c. The genetic toolkit d. DNA chip technology e. Hormone treatments Answer: b Textbook Reference: 20.0 The eyes have it Page: 426 Bloom’s Category: 2. Understanding 5. Which of the following is not a general principle of evo-devo? a. Most animals share similar molecular mechanisms underlying development. b. Different developmental processes usually operate independently from one another. c. Changes in the timing of expression of particular genes often play a major role in morphological modifications that occur throughout evolution. d. Changes in the location of expression of particular genes often play a major role in morphological modifications that occur throughout evolution. e. All of the above are true; none is false. Answer: e Textbook Reference: 20.1 What Is Evo-Devo? Page: 427 Bloom’s Category: 1. Remembering 6. A mutation that affects the length of wing in a fly, but has little or no effect elsewhere in the body, would be explained by the phenomenon of a. heterochrony. b. homeosis. c. pleiotropy. d. developmental plasticity. e. modularity. Answer: e Textbook Reference: 20.1 What Is Evo-Devo? Page: 427 Bloom’s Category: 2. Understanding 7. In studies of gene expression, which of the following would be the least likely observation? a. Expression of a gene important in developmental processes varies with temperature. b. One insect species has a pair of wings that its relatives lack; these evolved as the result of a radically different developmental process. c. A species of fish is much larger than its relatives because of the much earlier expression of a gene that affects bone growth. d. The amino acid sequence of a Hox gene protein is extremely similar in nematodes and humans. e. The expression pattern of a gene important in development is more restricted in its spatial result in one rodent species than in all others; this leads to that species having a narrower face. Answer: b Textbook Reference: 20.1 What Is Evo-Devo? Page: 427 Bloom’s Category: 2. Understanding 8. Which of the following statements about Hox genes is false? a. They are part of the so-called genetic toolkit. b. There are expressed in similar patterns in the embryos of both mice and flies. c. They are arranged in similar clusters of genes in both mice and flies. d. Because of their important functional roles, they evolve rapidly in both mammals and flies. e. All of the above are true; none is false. Answer: d Textbook Reference: 20.1 What Is Evo-Devo? Page: 428 Bloom’s Category: 2. Understanding 9. The Pax6 gene in mammals and the eyeless gene in flies are both genes. a. heterochronic b. developmentally plastic c. homologous d. diapause e. modular Answer: c Textbook Reference: 20.1 What Is Evo-Devo? Page: 428 Bloom’s Category: 2. Understanding 10. If you know that a Hox gene, AbdB, is expressed in the most posterior part of the abdomen in a Drosophila embryo, which of the following conclusions about a homologous gene in humans would most likely be correct? a. There is no homologous gene to abdB in humans, because the evolutionary distance between humans and flies is so great. b. The homologous gene to abdB exists in humans, but it is expressed only in adults, not in human embryos. c. The homologous gene to abdB exists and is expressed in the head of human embryos. d. The homologous gene to abdB exists and is expressed throughout the human embryo in roughly equal amounts.