1. According to the concept of punctuated equilibrium,

2. Two species of frogs belonging to the same genus occasionally mate, but the offspring fail to develop and hatch. What is the mechanism for keeping the two frog species separate?

3. Which of these should decline in hybrid zones where reinforcement is occurring?

4. There is still some controversy among biologists about whether Neanderthals should be placed within the same species as modern humans or into a separate species of their own. Most DNA sequence data analyzed so far indicate that there was probably little or no gene flow between Neanderthals and Homo sapiens. Which species concept is most applicable in this example?

5. Beetle pollinators of a particular plant are attracted to its flowers' bright orange color. The beetles not only pollinate the flowers, but they mate while inside of the flowers. A mutant version of the plant with red flowers becomes more common with the passage of time. A particular variant of the beetle prefers the red flowers to the orange flowers. Over time, these two beetle variants diverge from each other to such an extent that interbreeding is no longer possible. What kind of speciation has occurred in this example, and what has driven it?

6. Theoretically, the production of sterile mules by interbreeding between female horses (mares) and male donkeys (jacks) should

7. Rank the following from most general to most specific: 1.gametic isolation 2.reproductive isolating mechanism 3.pollen-stigma incompatibility 4.prezygotic isolating mechanism

8. Which of the following statements about species, as defined by the biological species concept, is (are) correct?
I.Biological species are defined by reproductive isolation.
II. Biological species are the model used for grouping extinct forms of life.
III.The biological species is the largest unit of population in which successful interbreeding is possible.

9. The largest unit within which gene flow can readily occur is a

10. Two closely related populations of mice have been separated for many generations by a river. Climatic change causes the river to dry up, thereby bringing the mice populations back into contact in a zone of overlap. Which of the following is not a possible outcome when they meet?

11. Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent?

12. Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have overlapping ranges. If pollen grains (which contain sperm cells) from one species are unable to germinate and make pollen tubes on female ovules (which contain egg cells) of the other species, then which of these terms are applicable? 1.sympatric species 2.prezygotic isolation 3.postzygotic isolation 4.allopatric species 5.habitat isolation 6.reduced hybrid fertility

13. A hybrid zone is properly defined as

14. Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools?

15. A narrow hybrid zone separates the toad species Bombina bombina and Bombina variegata. What is true of those alleles that are unique to the parental species?

16. Which of the following statements about speciation is correct?

17. What is true of macroevolution?

18. You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use?

19. According to the concept of punctuated equilibrium, the 'sudden' appearance of a new species in the fossil record means that

20. Suppose that a group of male pied flycatchers migrated from a region where there were no collared flycatchers to a region where both species were present. Assuming events like this are very rare, which of the following scenarios is least likely?

21. Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have overlapping ranges. If pollen grains (which contain sperm cells) from one species are unable to germinate and make pollen tubes on female ovules (which contain egg cells) of the other species, then which of these terms is applicable?

22. In order for speciation to occur, what must be true?

23. What is true of the flightless cormorants of the Galápagos Islands?

24. When male horses (stallions) and female donkeys (jennets) mate, they produce a sterile hybrid called a hinny. Hinnies occur much less frequently than do mules, but are just as healthy and robust as mules. Logically, which of the following best accounts for the relative rarity of hinnies, and what kind of prezygotic isolating mechanism is at work here?

25. The most likely explanation for the high rate of sympatric speciation that apparently existed among the cichlids of Lake Victoria in the past is