1. What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth? 1.origin of mitochondria 2.origin of multicellular eukaryotes 3.origin of chloroplasts 4.origin of cyanobacteria 5.origin of fungal-plant symbioses

2. Several scientific laboratories across the globe are involved in research concerning the origin of life on Earth. Which of these questions is currently the most problematic and would have the greatest impact on our understanding if we were able to answer it?

3. Which of the following is the correct sequence of events in the origin of life?
I.formation of protobionts
II.synthesis of organic monomers
III.synthesis of organic polymers
IV.formation of DNA -based genetic systems

4. Which of these observations gives the most support to the endosymbiotic theory for the origin of eukaryotic cells?

5. Approximately how far back in time does the fossil record extend?

6. The loss of ventral spines by modern freshwater sticklebacks is due to natural selection operating on the phenotypic effects of Pitx1 gene

7. Bagworm moth caterpillars feed on evergreens and carry a silken case or bag around with them in which they eventually pupate. Adult female bagworm moths are larval in appearance; they lack the wings and other structures of the adult male and instead retain the appearance of a caterpillar even though they are sexually mature and can lay eggs within the bag. This is a good example of

8. An organism has a relatively large number of Hox genes in its genome. Which of the following is true of this organism?

9. What is true of the fossil record of mammalian origins?

10. Larval flies (maggots) express the Ubx gene in all of their segments, and thereby lack appendages. If this same gene continued to be expressed throughout subsequent developmental stages, except in the head region, and if the result was a fit, sexually mature organism that still strongly resembled a maggot, this would be an example of

11. A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of

12. Adaptive radiations can be a direct consequence of four of the following five factors. Select the exception.

13. If one organ is an exaptation of another organ, then what must be true of these two organs?

14. The synthesis of new DNA requires the prior existence of oligonucleotides to serve as primers. On Earth, these primers are small RNA molecules. This latter observation is evidence in support of the hypothesized existence of

15. If natural selection in a particular environment favored genetic systems that permitted the production of daughter 'cells' that were genetically dissimilar from the mother 'cells,' then one should expect selection for which of the following?
I.polynucleotide polymerase with low mismatch error rates
II.polynucleotide polymerases without proofreading capability
III.batteries of efficient polynucleotide repair enzymes
IV.polynucleotide polymerases with proofreading capability
V.polynucleotide polymerases with high mismatch error rates

16. Which of the following statements provides the strongest evidence that prokaryotes evolved before eukaryotes?

17. Which of the following is a defining characteristic that all protobionts had in common?

18. Which event is nearest in time to the end of the period known as snowball Earth?

19. A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb. This type of change is illustrative of

20. Recent evidence indicates that the first major diversification of multicellular eukaryotes may have coincided in time with the

21. How were conditions on the early Earth of more than 3 billion years ago different from those on today's Earth?

22. What is true of the amino acids that might have been delivered to Earth within carbonaceous chondrites?

23. Which of the following steps has not yet been accomplished by scientists studying the origin of life?

24. Many species of snakes lay eggs. However, in the forests of northern Minnesota where growing seasons are short, only live-bearing snake species are present. This trend toward species that perform live birth in a particular environment is an example of

25. If two continents converge and are united, then the collision should cause