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30. Two juniper trees (Juniperus scopulorum and Juniperus monosperma) have overlapping geographic ranges. 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. Which of the following isolating mechanisms keeps the two species separate? A. habitat isolation B. temporal isolation gametic isolation D. behavioral isolation 31. Male fireflies of different species have unique flashing patterns during courtship. Size Females of each species only respond to the specific pattern of their own species. This is an example of what type of reproductive isolating mechanism? A. temporal isolation B. habitat isolation C. mechanical isolation D behavioral isolation 6 32. Two populations of Anopheles gambiae, the mosquito responsible for transmitting Palet malaria, live in the same regions of Africa, but are beginning to exhibit reproductive isolation. These two groups may be at the beginning stages of A. Allopatric speciation. B Sympatric speciation. C. Stabilizing selection. D. Balancing selection. 33. A dam is constructed in a stream to produce hydropower. Suppose a population of guppies is found in this stream reach and the populations become totally reproductively isolated by the dam. What else is necessary for speciation occur? A. Nothing. The conditions described are sufficient for speciation to occur. B. Enhanced gene flow. O Sexual selection for larger males. D Genetic divergence. 34. Which of the following would be LEAST likely to result in sympatric speciation? A. A nondisjunction event resulting in the complete duplication of an individual plant's genome. D. A mutation that improves access to prey in one type of habitat but comes at a fitness cost in another habitat that is also utilized by the species. C. A mutation that increases the number of offspring in a brood. M