Mastering Biology Chapter 24

-an area where mating occurs between members of two closely related species, producing viable offspring.

A hybrid zone is properly defined as -a zone that includes the intermediate portion of a cline. -an area where mating occurs between members of two closely related species, producing viable offspring. -an area where two closely related species' ranges overlap. -an area where members of two closely related species intermingle, but experience no gene flow. -a zone that features a gradual change in species composition where two neighboring ecosystems border each other.

punctuated equilibrium

According to the _____ model, evolution occurs in spurts; species evolve relatively rapidly then remain unchanged for long periods. geographic isolation adaptive radiation nondisjunction punctuated equilibrium gradualist

-a set of organisms with a unique genetic history ****The phylogenetic species concept relies on finding unique organisms with a unique genetic history.

According to the phylogenetic species concept, what is a species? -a clone of genetically identical organisms -a population that interbreeds and produces fertile offspring -a population with a distinct fossil record -a population that is physically able to mate even if there are no offspring or the offspring are infertile -a set of organisms with a unique genetic history

2 and 4

Among known plant species, which of these have been the two most commonly occurring phenomena that have led to the origin of new species? 1. allopatric speciation 2. sympatric speciation 3. sexual selection 4. polyploidy 2 and 4 1 and 4 1 and 3 2 and 3

-The two forms interbreed often in nature, and their offspring have good survival and reproduction.

Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species. Recently, these birds have been classified as eastern and western forms of a single species, the yellow-rumped warbler. Which of the following pieces of evidence, if true, would be cause for this reclassification? -The two forms interbreed often in nature, and their offspring have good survival and reproduction. -The two forms have many genes in common. -The two forms live in similar habitats. -The two forms are very similar in coloration. -The two forms have similar food requirements.

(:

1 is a pic

:)

14 and 15 are pics

;)

18 and 19 are pics

((:

24 and 25 are pics

1, 3, or 4

On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mosquitofish that can swim continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences. The predatory fish rely on visual cues and speed to capture mosquitofish. Mosquitofish rely on speed and visual cues to avoid the predatory fish. Which adaptation(s) might help the predators survive in ponds that are home to faster mosquitofish? 1. directional selection for increased speed 2. stabilizing selection for speed that matches that of the mosquitofish 3. change in hunting behavior that replaces reliance on visual cues with reliance on tactile cues, which can be used to hunt at night 4. change in hunting behavior that eliminates speed in favor of better camouflage, which permits an ambush strategy 1 only 2 only either 1 or 3 either 2 or 3 1, 3, or 4

1 and 2

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 1 and 2 2 and 4 1, 3, and 6 2, 4, and 5 1, 2, 5, and 6

mechanical isolation

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? hybrid breakdown reduced hybrid viability behavioral isolation mechanical isolation

-Sympatric speciation can occur in a single generation.

Select the correct statement describing sympatric speciation. -Sympatric speciation is always initiated by geographic isolation of two populations. -Sympatric speciation has never been observed in nature. -Sympatric speciation can occur in a single generation.

gene flow ****Gene flow refers to the transfer of alleles among populations. As long as populations are exchanging alleles, speciation is unlikely.

What is the most important factor that holds a gene pool of a species together and prevents speciation? gene flow sexual selection hybridization behavioral isolation prezygotic barriers

-Gene flow between the two populations is extensive.

Which of the following factors would not contribute to allopatric speciation? -The isolated population is exposed to different selection pressures than the ancestral population. -The separated population is small, and genetic drift occurs. -Different mutations begin to distinguish the gene pools of the separated populations. -Gene flow between the two populations is extensive. -A population becomes geographically isolated from the parent population.

I and III

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. I and II I and III II and III I, II, and III

-One species is nocturnal, and the other species is not. ****In temporal isolation, two species that breed during different times of the day cannot mix their gametes.

Which of these is an example of temporal isolation? -One species is nocturnal, and the other species is not. -One is a type of primate, the other is a type of marsupial. -One species performs a specific courtship dance. the other species does not. -The average weight of the individuals in one species is 45 kg; in the other species the average is 290 kg. -One species is found only in New York, the other only in London.

morphological

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? ecological morphological biological phylogenetic

-Hybrids have poor survival and reproduction and thus produce few viable offspring with members of either parent species.

In Europe, there is a long narrow hybrid zone, shown in red on the map, between the high-altitude habitat of the yellow-bellied toad and the lowland habitat of the fire-bellied toad. Despite this, there is little gene flow between the two species. Select the correct explanation. -Toads mate only with their own kind in order to avoid producing unhealthy hybrid young. -Hybrids have poor survival and reproduction and thus produce few viable offspring with members of either parent species. -Yellow-bellied toads and fire-bellied toads are two different species.

-At least one gene, affecting at least one phenotypic trait, must change.

In order for speciation to occur, what must be true? -At least one gene, affecting at least one phenotypic trait, must change. -Large numbers of genes that affect a single phenotypic trait must change. -Large numbers of genes that affect numerous phenotypic traits must change. -Changes to centromere location or chromosome size must occur within the gene pool. -The number of chromosomes in the gene pool must change.

-Build a canal linking the two ponds that permits free movement of mosquitofish, but not of predators.

On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mosquitofish that can swim continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences. What is the best way to promote fusion between two related populations of mosquitofish, one of which lives in a predator-rich pond, and the other of which lives in a predator-poor pond? -Transfer only female mosquitofish from a predator-rich pond to a predator-poor pond. -Remove predators from a predator-rich pond and transfer them to a predator-poor pond. -Build a canal linking the two ponds that permits free movement of mosquitofish, but not of predators. - Perform a reciprocal transfer of females between predator-rich and predator-poor ponds.

behavioral isolation

On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mosquitofish that can swim continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences. Which type of reproductive isolation operates to keep the mosquitofish isolated, even when fish from different ponds are reunited in the same body of water? behavioral isolation mechanical isolation temporal isolation gametic isolation habitat isolation

hybrid sterility

On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands, and is also found on the African mainland, located about 200 miles away. At higher elevations, and only on Sao Tomé, is found the very closely related Drosophila santomea. The two species can hybridize, though male hybrids are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly outnumbered by D. santomea. Studies of the two species' nuclear genomes reveal that D. yakuba on the island is more closely related to mainland D. yakuba than to D. santomea (2n = 4 in both species). Sao Tomé rose from the Atlantic Ocean about 14 million years ago. Which of the following reduces gene flow between the gene pools of the two species on Sao Tomé, despite the existence of hybrids? a geographic barrier hybrid sterility temporal isolation hybrid breakdown hybrid inviability

-an increasing number of viable, fertile hybrids is produced over the course of generations.

The phenomenon of fusion is likely to occur when, after a period of geographic isolation, two populations meet again and -a constant number of viable, fertile hybrids is produced over the course of generations. -a decreasing number of viable, fertile hybrids is produced over the course of generations. -the hybrid zone is inhospitable to hybrid survival. -an increasing number of viable, fertile hybrids is produced over the course of generations. - their chromosomes are no longer homologous enough to permit meiosis.

biological

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? phylogenetic biological morphological ecological

-the postzygotic barrier called hybrid inviability

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? -the postzygotic barrier called hybrid inviability -the postzygotic barrier called hybrid breakdown -gametic isolation -the prezygotic barrier called hybrid sterility