BIOLOGY CHAPTER 23 PART 2 HW

gene flow

-can introduce new alleles into a population's gene pool -a result of the movement of fertile individuals or their gametes

natural selection

-consistently causes a population to become better adapted -to its environment -A result of differential success in reproduction -cannot cause a harmful allele to become more common

genetic drift

-responsible for the founder effect -responsible for the bottleneck effect -causes allele frequencies to fluctuate randomly

In 1949, Dr. Tony Allison observed a high frequency of Kenyans carrying the sickle cell allele in coastal areas and near Lake Victoria, but a lower frequency in the highlands. What did he hypothesize? A] He hypothesized that malaria is a genetic disease. B] He hypothesized that there was a connection between malaria and sickle cell disease. C] He hypothesized that malaria causes sickle cell disease. D] He hypothesized that sickle cell disease was an environmental, not a genetic disease.

He hypothesized that there was a connection between malaria and sickle cell disease.

1. During an extreme heat wave, plants with white flowers survive better

a. Natural Selection b. White allele increases

3. a storm kills many plants

e. genetic drift f. allele frequencies change but not predictably

5. workers in a greenhouse...

i. gene flow j. frequency of white allele increases

Which of the following are causes of evolutionary change? A] mutation B] gene flow C] genetic drift D] natural selection

mutation gene flow genetic drift natural selection

In some jacana species, males take care of the eggs and young, and females compete among themselves for territories that contain one to several males. Female jacanas are significantly larger than males. Which of these statements would you predict to be true of this bird species? 1. Male jacana fitness is primarily limited by ability to take care of eggs and raise young. 2. Female jacana fitness is limited by the number of males in her territory with which a female mates. 3. Variation in reproductive success should be greater in male jacanas than in females. 4. Variation in reproductive success should be greater in female jacanas than in males. 5. Males and females have equal variation in reproductive success. A] 1, 2, and 4 B] 1 and 3 C] 2 and 4 D] 5

A] 1, 2, and 4

In 1986, a nuclear power accident in Chernobyl, USSR (now Ukraine), led to high radiation levels for miles surrounding the plant. The high levels of radiation caused elevated mutation rates in the surviving organisms, and evolutionary biologists have been studying rodent populations in the Chernobyl area ever since. Based on your understanding of evolutionary mechanisms, which of the following most likely occurred in the rodent populations following the accident? A] Mutation led to increased genetic variation. B] Mutations caused major changes in rodent physiology over time. C] Mutation caused genetic drift and decreased fitness. D] Mutation caused the fixation of new alleles.

A] Mutation led to increased genetic variation.

Which of the following is true? A] Over time, the bedbug that feeds on bats will likely become less similar to the bedbug that feeds on humans. B] The populations of bedbugs that feed on humans are too variable to adequately compare to bedbugs that feed on bats. C] Over time, the bedbug that feeds on bats will likely become more similar to the bedbug that feeds on humans. D] Over time, there will be no changes in the bedbugs that feed on humans or bats.

A] Over time, the bedbug that feeds on bats will likely become less similar to the bedbug that feeds on humans.

Compare sickle cell disease and malaria. A] Sickle cell disease and malaria are both potentially lethal diseases. B] Sickle cell disease and malaria are both genetic diseases. C] Sickle cell disease and malaria are both inherited diseases. D] Sickle cell disease and malaria are both infectious diseases.

A] Sickle cell disease and malaria are both potentially lethal diseases.

Women often have complications during labor while giving birth to very large babies, whereas very small babies tend to be underdeveloped. Which kind of selection is most likely at work regarding the birth weight of babies? A] Stabilizing selection B] Disruptive selection C] Directional selection

A] Stabilizing selection

Which of the following is true? A] The bedbug that feeds on humans can interbreed with the bedbug that feeds on bats, though they do not typically do so. B] The bedbug that feeds on humans can interbreed with the bedbug that feeds on bats, and they do so frequently. C] It is unknown as to whether or not the bedbug that feeds on humans can interbreed with the bedbug that feeds on bats. D] The bedbug that feeds on humans cannot interbreed with the bedbug that feeds on bats.

A] The bedbug that feeds on humans can interbreed with the bedbug that feeds on bats, though they do not typically do so.

If a person has two normal copies of the hemoglobin allele, which statements are true? A] The person is susceptible to malaria. B] The person is homozygous at the hemoglobin locus. C] The person is heterozygous at the hemoglobin locus. D] The person is protected against malaria.

A] The person is susceptible to malaria. B] The person is homozygous at the hemoglobin locus.

Predict what will happen to the frequency of the sickle cell allele in areas where malaria has been eradicated. A] The sickle cell allele will decrease in frequency. B] The sickle cell allele will increase in frequency. C] The sickle cell allele frequency will not be affected.

A] The sickle cell allele will decrease in frequency.

In a bell-shaped curve, the x-axis (horizontal direction) of the graph represents which of the following? A] The value of a particular characteristic; characteristics of an organism can include such traits as size and color. C] Time D] The number of individuals

A] The value of a particular characteristic; characteristics of an organism can include such traits as size and color.

Genetic drift produces variation for evolution when ________. A] chance events cause allele frequencies to fluctuate unpredictably B] a population has heritable traits better suited to the environment C] sudden change in environment drastically reduces the gene pool D] a gene pool decreases because a smaller group establishes a new population

A] chance events cause allele frequencies to fluctuate unpredictably

Blue poppies native to China were grown at a plant-breeding center in California. The plants with the thickest leaves were most likely to survive and reproduce in the drier climate. After several generations, the percentage of thick-leaved plants had increased by 42%. This adaptation of the poppies to their new environment is due to _____. A] directional selection B] genetic drift C] stabilizing selection D] disruptive selection E] neutral variation

A] directional selection

Three-spined stickleback fish (Gasterosteus aculeatus) show substantial heritable variation in gill-raker length related to differences in their diets. Longer gill rakers appear to function better for capturing open-water prey, while shorter gill rakers function better for capturing shallow-water prey. Which of the following types of selection is most likely to be found in a large lake (open water in the middle and shallow water around the sides) with a high density of these fish? A] disruptive selection B] stabilizing selection C] sexual selection D] directional selection

A] disruptive selection

Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing _____. A] gene flow B] geographic isolation C] nonrandom mating D] genetic drift

A] gene flow

The Dunkers are a religious group that moved from Germany to Pennsylvania in the mid-1700s. They do not marry with members outside their own immediate community. Today, the Dunkers are genetically unique and differ in gene frequencies, at many loci, from all other populations including those in their original homeland. Which of the following likely explains the genetic uniqueness of this population? A] heterozygote advantage and stabilizing selection B] founder effect and genetic drift C] mutation and natural selection D] population bottleneck and Hardy-Weinberg equilibrium

B] founder effect and genetic drift

A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. The actual forelimbs of these mammals do not seem to be optimally arranged because _____. A] natural selection is generally limited to modifying structures that were present in previous generations and in previous species B] natural selection has not had sufficient time to create the optimal design in each case, but will do so given enough time C] in many cases, phenotype is determined by genotype and the environment D] though we may not consider the fit between the current skeletal arrangements and their functions excellent, we should not doubt that natural selection ultimately produces the best design

A] natural selection is generally limited to modifying structures that were present in previous generations and in previous species

The evolutionary effects of genetic drift are greatest when _____. A] the population size is small B] intraspecific competition is weak C] sexual selection occurs D] intraspecific competition is intense E] the population size is large

A] the population size is small

Which type of selection tends to increase genetic variation? A] Stabilizing selection B] Disruptive selection C] Directional selection

B] Disruptive selection

True or false? Heterozygote advantage refers to the tendency for heterozygous individuals to have better fitness than homozygous individuals. This higher fitness results in less genetic variation in the population. A] True B] False

B] False

Swine are vulnerable to infection by bird flu virus and human flu virus, which can both be present in an individual pig at the same time. When this occurs, it is possible for genes from bird flu virus and human flu virus to be combined. If the human flu virus contributes a gene for Tamiflu resistance (Tamiflu is an antiviral drug) to the new virus, and if the new virus is introduced to an environment lacking Tamiflu, then what is most likely to occur? A] The new virus will maintain its Tamiflu-resistance gene, in case of future exposure to Tamiflu. B] If the Tamiflu-resistance gene involves a cost, it will experience directional selection leading to reduction in its frequency. C] The Tamiflu-resistance gene will undergo mutations that convert it into a gene that has a useful function in this environment. D] If the Tamiflu-resistance gene confers no benefit in the current environment, and has no cost, the virus will increase in frequency.

B] If the Tamiflu-resistance gene involves a cost, it will experience directional selection leading to reduction in its frequency.

How does Dr. Allison's work provide an example of natural selection in humans? A] Natural selection caused the sickle cell allele to appear in east African populations. B] In areas with malaria, individuals with one sickle cell allele reproduced at higher rates than those with no sickle cell alleles. C] In areas without malaria, individuals with two sickle cell alleles reproduced at lower rates than those without sickle cell disease. D] In areas with malaria, natural selection causes individuals to acquire the sickle cell allele as protection against malaria.

B] In areas with malaria, individuals with one sickle cell allele reproduced at higher rates than those with no sickle cell alleles. C] In areas without malaria, individuals with two sickle cell alleles reproduced at lower rates than those without sickle cell disease.

Which of the following does current research most support? A] The common bedbug did not live with bats and humans at concurrent times. B] The common bedbug lived with bats first, then humans. C] The common bedbug has only been known to live with humans. D] The common bedbug lived with humans first, then bats.

B] The common bedbug lived with bats first, then humans.

Long necks make it easier for giraffes to reach leaves high on trees, while also making them better fighters in "neck wrestling" contests. In both cases, which kind of selection appears to have made giraffes the long-necked creatures they are today? A] Stabilizing selection B] Disruptive selection C] Directional selection

C] Directional selection

Black-bellied seedcrackers have either small beaks (better for eating soft seeds) or large beaks (better for hard seeds). There are no seeds of intermediate hardness; therefore, which kind of selection acts on beak size in seedcrackers? A] Directional selection B] Stabilizing selection C] Disruptive selection

C] Disruptive selection

How did Dr. Allison test his hypothesis that sickle cell disease was connected to malaria? A] He looked for the underlying genetic mechanism causing sickle cell disease. B] He studied the way that the malaria parasite interacts with sickle cells. C] He evaluated blood samples for malaria parasites and the presence of sickle cells. D] He expanded his study area beyond Kenya to the rest of East Africa to see if malaria and sickle disease were connected.

C] He evaluated blood samples for malaria parasites and the presence of sickle cells. D] He expanded his study area beyond Kenya to the rest of East Africa to see if malaria and sickle disease were connected.

Small Aristelliger lizards have difficulty defending territories, but large lizards are more likely to be preyed upon by owls. Which kind of selection acts on the adult body size of these lizards? A] Disruptive selection B] Directional selection C] Stabilizing selection

C] Stabilizing selection

Which of the following led to the greatest decline of bedbug populations in the mid twentieth century? A] The increased use of running water in homes. B] The use of washing machines. C] The use of pesticides, namely DDT. D] Highly improved laundering soaps.

C] The use of pesticides, namely DDT.

In evolutionary terms, an organism's fitness is measured by its A] health B] genetic variability C] contribution to the gene pool of the next generation D] stability in the face of environmental change E] mutation rate

C] contribution to the gene pool of the next generation

What is the only evolutionary mechanism that consistently leads to adaptive evolution? A] the bottleneck effect B] gene flow C] natural selection D] neutral variation E] genetic drift

C] natural selection

Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer or more than this have reduced fitness. Which of the following terms best describes this situation? A] disruptive selection B] sexual selection C] stabilizing selection D] directional selection

C] stabilizing selection

In some populations, 1 in 500 people have sickle cell disease. What reason does the film give for why a potentially deadly, inherited disease is found at such high frequencies? A] Sickle cell alleles are new mutations and not enough time has gone by for these alleles to be eliminated from the population by natural selection. B] Individuals with two sickle cell alleles have an evolutionary advantage because they do not get sickle cell disease or get infected with malaria. C] Individuals with two normal hemoglobin alleles get both sickle cell disease and are susceptible to malaria, so these alleles are eliminated from the population. D] Individuals with one sickle cell allele are protected from malaria and do not have sickle cell disease, thus keeping the allele in the population.

D] Individuals with one sickle cell allele are protected from malaria and do not have sickle cell disease, thus keeping the allele in the population.

Which of the following is true? A] Populations of bedbugs that feed on bats and populations of bats that feed on humans would have equal resistance to pesticides. B] Populations of bedbugs that feed on bats are more likely to be resistant to pesticides than populations of bedbugs that feed on humans. C] When it comes to pesticide resistance, populations of bedbugs that feed on bats are too random to compare to populations of bedbugs that feed on humans. D] Populations of bedbugs that feed on humans are more likely to be resistant to pesticides than populations of bedbugs that feed on bats.

D] Populations of bedbugs that feed on humans are more likely to be resistant to pesticides than populations of bedbugs that feed on bats.

An earthquake decimates a ground-squirrel population, killing 98% of the squirrels. The surviving population happens to have broader stripes, on average, than the initial population. If broadness of stripes is genetically determined, what effect has the ground-squirrel population experienced during the earthquake? A] disruptive selection B] a founder event C] directional selection D] a genetic bottleneck

D] a genetic bottleneck

You are maintaining a small population of fruit flies in the laboratory by transferring the flies to a new culture bottle after each generation. After several generations, you notice that the viability of the flies has decreased greatly. Recognizing that small population size is likely to be linked to decreased viability, the best way to reverse this trend is to _____. A] change the temperature at which you rear the flies B] transfer only the largest flies C] reduce the number of flies that you transfer at each generation D] cross your flies with flies from another lab

D] cross your flies with flies from another lab

Which of the following is the most predictable outcome of increased gene flow between two populations? A] lower average fitness in both populations B] higher average fitness in both populations C] increased genetic difference between the two populations D] decreased genetic difference between the two populations

D] decreased genetic difference between the two populations

Homozygotes with two sickle-cell alleles are selected against because of mortality. However, heterozygotes for sickle-cell allele experience little effects of sickle allele and are more likely to survive malaria. The net effect of this exposure produced evolutionary change in areas where malaria is endemic by ________. A] increasing the number of infected mosquitoes B] causing sickle-cell allele C] distortion of red blood cells D] increasing sickle-cell allele frequency

D] increasing sickle-cell allele frequency

Generation-to-generation change in the allele frequencies in a population is _____. A] genetic drift B] mutation C] macroevolution D] microevolution E] natural selection

D] microevolution

2. A person uproots the five closest plants, which all happens to have white flowers

c. genetic drift d. frequency of purple allel increases

In 1983, a population of dark-eyed junco birds became established on the campus of the University of California, San Diego (UCSD), which is located many miles from the junco's normal habitat in the mixed-coniferous temperate forests in the mountains. Juncos have white outer tail feathers that the males display during aggressive interactions and during courtship displays. Males with more white in their tail are more likely to win aggressive interactions, and females prefer to mate with males with more white in their tails. Females have less white in their tails than do males, and display it less often. (Pamela J. Yeh. 2004. Rapid evolution of a sexually selected trait following population establishment in a novel habitat. Evolution 58[1]:166-74.) The UCSD campus male junco population tails were, on average, 36% white, whereas the tails of males from nearby mountain populations averaged 40-45% white. If this observed trait difference were due to a difference in the original colonizing population, it would most likely be due to ________. A] a founder effect B] a genetic bottleneck C] gene flow between populations D] mutations in the UCSD population

founder effect

What situation most likely explains the occasional high frequency of certain inherited disorders among human populations established by a small population? See Concept A] founder effect B] gene flow C] mutation D] bottleneck effect E] nucleotide variability

founder effect

4.plants with purple flowers attract more insects, which pollinate the plants

g. Natural selection h. frequency of purple allele increases

In 1983, a population of dark-eyed junco birds became established on the campus of the University of California, San Diego (UCSD), which is located many miles from the junco's normal habitat in the mixed-coniferous temperate forests in the mountains. Juncos have white outer tail feathers that the males display during aggressive interactions and during courtship displays. Males with more white in their tail are more likely to win aggressive interactions, and females prefer to mate with males with more white in their tails. Females have less white in their tails than do males, and display it less often. (Pamela J. Yeh. 2004. Rapid evolution of a sexually selected trait following population establishment in a novel habitat. Evolution 58[1]:166-74.) The UCSD campus male junco population tails are about 36% white, whereas the tails of males from nearby mountain populations are about 40-45% white. The founding stock of UCSD birds was likely from the nearby mountain populations because some of those birds overwinter on the UCSD campus each year. Population sizes on the UCSD campus have been reasonably large, and there are significant habitat differences between the UCSD campus and the mountain coniferous forests; UCSD campus has a more open environment (making birds more visible) and a lower junco density (decreasing intraspecific competition) than the mountain forests. Given this information, which of the following evolutionary mechanisms do you think is most likely responsible for the difference between the UCSD and mountain populations? a] gene flow b] mutation c] natural selection d] genetic drift

natural selection