week 10 part 1 mastering bio

Researchers hypothesize that the severe winter of 2010 caused the decline in the number of pythons encountered that year. Is cold weather typically a density-dependent factor or a density-independent factor? Explain the difference. ----is typically a -----factor because it affects the pythons the same way no matter whether there are few or many pythons. A -----factor, such as------ , increases with increasing python density.

----Density-independent---- is typically a ---cold weather ----factor because it affects the pythons the same way no matter whether there are few or many pythons. A----- density-dependent ------factor, such as---- competition for food-----, increases with increasing python density.

Assume there are 200 MendAliens living on an island in my back yard. If my island has an area of 20 hectares, what is the population density of MendAliens in terms of MendAliens per hectare? Assume there are 200 MendAliens living on an island in my back yard. If my island has an area of 20 hectares, what is the population density of MendAliens in terms of MendAliens per hectare? 10 MendAliens per hectare 4,000 MendAliens per hectare 4 MendAliens per hectare 200 MendAliens per hectare 0.1 MendAliens per hectare

10 MendAliens per hectare

A population is growing exponentially and its instantaneous growth rate (r) is 0.02. Would the number of individuals added to the population (rN) be greatest at a population size (N) of 20, 500 or 1000? See Section 51.3 (Page) . 1000 500 20 All the populations would have the same number of individuals added to them since r is constant.

1000

Suppose researchers marked 800 turtles and later were able to trap a total of 300 individuals in that population, of which 150 were marked. What is the estimate for total population size? Suppose researchers marked 800 turtles and later were able to trap a total of 300 individuals in that population, of which 150 were marked. What is the estimate for total population size? 1050 2100 1600 200

1600

You are doing a mark-recapture experiment to determine the population size of the MendAliens living on an island in my back yard. Initially, you catch and mark 130 MendAliens, which you then release. Next, you capture 90 MendAliens, of which 20 are marked. What is your estimate of the population size of MendAliens living on the island in my back yard? 14 234,000 130 585 29

585

Estimate total population size in a mark-recapture study in which 200 individuals were initially marked, and you recaptured 150 of which 50 were marked 600 67 530 630

600

The range of Burmese pythons in Florida is expanding rapidly. List abiotic factors and biotic factors that might limit the range of pythons

Abiotic Factors -cold temperatures to the north -occurrence of deep seawater (Atlantic Ocean and Gulf of Mexico) surrounding southern Florida Biotic factor -increased predation on eggs or juveniles -competition for food -spread of disease -occurrence of parasites

In the accompanying figure, which of the lines represents exponential growth? line A line B line C line D All of the lines represent exponential growth.

All of the lines represent exponential growth.

Why do populations grow more slowly as they approach their carrying capacity? Density-independent factors lead to fewer births and increased mortality. Density-dependent factors lead to fewer births and increased mortality. Hormonal changes promote higher death rates in crowded populations. The incoming energy decreases in populations experiencing a high rate of increase. Individuals voluntarily stop mating so that overcrowding does not occur.

Density-dependent factors lead to fewer births and increased mortality.

Which of the following statements best summarizes evolution by natural selection as it is viewed today? Evolution by natural selection is the descent of humans from the present-day great apes. Evolution by natural selection represents the result of selection for acquired characteristics. Evolution by natural selection is the differential survival and reproduction of the most-fit phenotypes. Evolution by natural selection is the production of adaptations that meet present and anticipated needs.

Evolution by natural selection is the differential survival and reproduction of the most-fit phenotypes.

How might genotype frequencies of alleles for body size change under directional selection? See Section 23.3 (Page) . .Genotypes that represent both smaller and larger individuals become more prevalent. Genotypes that represent moderate-sized individuals become more prevalent. Genotypes that represent larger individuals become more prevalent. Genotypes do not change under directional selection.

Genotypes that represent larger individuals become more prevalent.

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

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

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? He hypothesized that malaria is a genetic disease. He hypothesized that malaria causes sickle cell disease. He hypothesized that there was a connection between malaria and sickle cell disease. 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.

How does inbreeding alter genotype and allele frequencies? See Section 23.2 (Page) . There is no change in genotype frequency. Heterozygotes increase in frequency in the population over generations. Dominant alleles become less prevalent in the population over generations. Homozygotes increase in frequency in the population over generations.

Homozygotes increase in frequency in the population over generations.

A population is correctly defined as having which of the following characteristics?I. inhabiting the same general areaII. belonging to the same speciesIII. possessing a constant and uniform density and dispersion A population is correctly defined as having which of the following characteristics? I. inhabiting the same general area II. belonging to the same species III. possessing a constant and uniform density and dispersion II and III only I and II only I only I, II, and III III only

I and II only

Looking at the data in the accompanying figure from the hare/lynx experiment, what conclusion can you draw? I. Food is a factor in controlling hare population size. II. Excluding lynx is a factor in controlling hare population size. III. The effect of excluding predators and adding food in the same experiment is greater than the sum of excluding lynx alone plus adding food alone. only II and III only I only III I, II, and III only II

I, II, and III

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

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

Will this population of lizards stay the same, increase, or decrease over time? See Section 51.6(Page) . Will this population of lizards stay the same, increase, or decrease over time? See Section 51.6 (Page) . Increase, since R0 >1 Increase, since R0 > 0 Stable, since R0 is equal to 1 Declining, since R0 < 1

Increase, since R0 >1 Correct. The number of offspring being produced easily replaces their parents.

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? Individuals with two sickle cell alleles have an evolutionary advantage because they do not get sickle cell disease or get infected with malaria. Individuals with one sickle cell allele are protected from malaria and do not have sickle cell disease, thus keeping the allele in the population. 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. Individuals with two normal hemoglobin alleles get both sickle cell disease and are susceptible to malaria, so these alleles are eliminated from the population.

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

How might genetic drift be important in a small population. See Section 23.4 (Page) . It increases genetic diversity by introducing alleles from one population into another. It decreases genetic diversity via sampling error during mating. It increases genetic diversity by introducing new genes into the DNA of a species. It decreases genetic diversity only by reducing population size.

It decreases genetic diversity via sampling error during mating.

How might gene flow be important in managing an endangered population? See Section 23.5 (Page) . It decreases genetic diversity via the loss of alleles due to inbreeding depression. It increases genetic diversity by introducing alleles from one population into another. It increases genetic diversity by introducing new genes into the DNA of a population. It is not important to managing an endangered species.

It increases genetic diversity by introducing alleles from one population into another.

Looking at the data in the accompanying figure, what can be said about survival and clutch size? Animals with low survival tend to have smaller clutch sizes. Animals with high survival tend to have larger clutch sizes. Large clutch size correlates with low survival. Probability of survivorship does not correlate with clutch size.

Large clutch size correlates with low survival.

Which of the following is the most important assumption for the mark-recapture method to estimate the size of wildlife populations? Which of the following is the most important assumption for the mark-recapture method to estimate the size of wildlife populations? There is a 50:50 ratio of males to females in the population before and after trapping and recapture. More individuals emigrate from, as opposed to immigrate into, a population. All females in the population have the same litter size. Marked individuals have the same probability of being recaptured as unmarked individuals during the recapture phase. Over 50% of the marked individuals need to be trapped during the recapture phase.

Marked individuals have the same probability of being recaptured as unmarked individuals during the recapture phase.

Which evolutionary mechanism results in adaptation? See Section 23.2 (Page) . Gene flow Genetic drift Mutation Natural selection

Natural selection

Which assumption must be correct for a population to be in Hardy-Weinberg equilibrium for a specific gene? See Section 23.1 (Page) . The number of immigrants must equal the number of organisms emigrating. No genetic drift can affect allele frequencies for the gene. Mating must be nonrandom with respect to the gene. Natural selection must favor one phenotype.

No genetic drift can affect allele frequencies for the gene.

For a gene suspected of causing hypertension in humans, you observe the following genotype frequencies: A1A1 0.574; A1A2 0.339; A2A2 0.087. Is this gene in Hardy-Weinberg equilibrium? Why or why not? (Assume that a difference of three percent or more in any of the observed versus expected frequencies is statistically significant.) Yes. The expected genotype frequencies are A1A1 0.553; A1A2 0.381; A2A2 0.066. No. The expected genotype frequencies are A1A1 0.553; A1A2 0.381; A2A2 0.166. No. The expected genotype frequencies are A1A1 0.553; A1A2 0.381; A2A2 0.066. Yes. The expected genotype frequencies are A1A1 0.574; A1A2 0.339; A2A2 0.087.

No. The expected genotype frequencies are A1A1 0.553; A1A2 0.381; A2A2 0.066.

Compare sickle cell disease and malaria. Sickle cell disease and malaria are both potentially lethal disease .Sickle cell disease and malaria are both infectious diseases. Sickle cell disease and malaria are both inherited diseases. Sickle cell disease and malaria are both genetic diseases.

Sickle cell disease and malaria are both potentially lethal disease

Pythons are generalist predators, consuming a wide variety of prey including birds, mammals ranging from rodents to deer, and alligators. A road survey showed a 99 percent decrease in the frequency of raccoon and opossum observations within python areas from 2003 to 2011. Rabbits and foxes have also disappeared from the area. Do you think food availability limits, or could limit, the carrying capacity of Burmese pythons in the Everglades? Drag the words on the left to the appropriate blanks on the right to complete the sentences Since pythons are----- , it would seem that food availability ------be a primary factor in determining the carrying capacity. However, the dramatic disappearance of raccoons and opossums indicates that predation rates are very------ and at least some food sources are disappearing. In the long run, the size of the python population will be------- (the population cannot increase --------forever).

Since pythons are ----generalists----, it would seem that food availability ----would not ----be a primary factor in determining the carrying capacity. However, the dramatic disappearance of raccoons and opossums indicates that predation rates are very ---high---- and at least some food sources are disappearing. In the long run, the size of the python population will ----be food-limited---- (the population cannot increase ---exponentially ----forever).

Suppose you trap some fish in a lake, mark them, and release them. Every month for a year you re-trap a similar number of the fish and release them. You notice each month that the proportion of marked fish trapped is declining. Which of the following is a reasonable explanation for this observation? See Section 51.2 (Page) . View Available Hint(s) Suppose you trap some fish in a lake, mark them, and release them. Every month for a year you re-trap a similar number of the fish and release them. You notice each month that the proportion of marked fish trapped is declining. Which of the following is a reasonable explanation for this observation? See Section 51.2 (Page) . The fish do not have long lifespans so some of the marked fish are dying each month. The marked fish are more susceptible to being trapped than unmarked fish. The fish population is decreasing. The marking of the fish increases their fitness.

The fish do not have long lifespans so some of the marked fish are dying each month.

As N approaches K for a certain population, which of the following is predicted by the logistic equation? The growth rate will not change. The population will increase exponentially. The carrying capacity of the environment will increase. The growth rate will approach zero. The population will show an Allee effect.

The growth rate will approach zero.

Why can't a female lizard have both high fecundity and high survival? Why can't a female lizard have both high fecundity and high survival? The female is already maximizing the number of eggs she lays, and if she attempts to nest later in the season, there will not be enough food for her young. In only rare cases, do lizards have both high fecundity and high survival. Competition for resources prevents this. Female lizards are able to produce only one set of offspring. The more energy the female devotes to offspring, the less that can be devoted to her survival.

The more energy the female devotes to offspring, the less that can be devoted to her survival.

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

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

What conclusion can you draw from the accompanying figure? What conclusion can you draw from the accompanying figure? Hares control lynx population size. Lynx and hare populations are independent of each other. Lynx control hare population size. The relationship between the populations cannot be determined only from this graph.

The relationship between the populations cannot be determined only from this graph

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

The sickle cell allele will decrease in frequency.

Number of survior 1000 424 308 158 57 10 7 2 Given the data in the table, which survivorship curve does Lacerta viviparta best resemble? Given the data in the table, which survivorship curve does Lacerta viviparta best resemble?See Section 51.2 (Page) . Type I Type II Type III Type IV

Type II

Use the following information to answer the question below.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]:16674.)Refer to the paragraph on dark-eyed junco birds. 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 __________. mutations in the UCSD population a genetic bottleneck gene flow between populations sexual selection a founder effect

a founder effect

In the accompanying figure, which of the arrows represents the carrying capacity? arrow A arrow B arrow C Carrying capacity cannot be found in the figure because species under density-dependent control never reach carrying capacity.

arrow C

Which of the following examples would most accurately measure the density of the population being studied? Which of the following examples would most accurately measure the density of the population being studied? counting the number of prairie dog burrows per hectare counting the number of zebras from airplane census observations. counting the number of coyote droppings per hectare counting the number of moss plants in 1-square-meter quadrants counting the number of times a 1-kilometer transect is intersected by tracks of red squirrels after a snowfall

counting the number of moss plants in 1-square-meter quadrants

Cystic fibrosis is a genetic disorder in homozygous recessive (ff) humans that typically significantly reduces life expectancy. Over time, we would expect the f allele frequency to ________ for this trait. remain the same increase fluctuate decrease

decrease

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

decreased genetic difference between the two populations

An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square kilometer in one woodlot and 20 per square kilometer in another woodlot. What was the ecologist comparing? An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square kilometer in one woodlot and 20 per square kilometer in another woodlot. What was the ecologist comparing? range cohorts carrying capacity dispersion density

density

Burmese pythons were first found in the wetlands of Everglades National Park in the 1980s, but only rarely. The graph shows what happened next. Most of the data are derived from chance encounters of pythons on roads (pythons are notoriously difficult to find). How would you describe the type of population growth in pythons from 2000 to 2008? Source: Dorcas, M. E., J. D. Willson, R. N. Reed, et al. 2012. Proceedings of the National Academy of Sciences 109: 2418−−2422. Burmese pythons were first found in the wetlands of Everglades National Park in the 1980s, but only rarely. The graph shows what happened next. Most of the data are derived from chance encounters of pythons on roads (pythons are notoriously difficult to find). How would you describe the type of population growth in pythons from 2000 to 2008? linear exponential logistic logarithmic

exponential

Cystic fibrosis is a genetic disorder in homozygous recessives that causes death during the teenage years. If 9 in 10,000 newborn babies have the disease, what are the expected frequencies of the dominant (A1) and recessive (A2) alleles according to the HardyWeinberg model? f(A1) = 0.9600, f(A2) = 0.040 f(A1) = 0.9997, f(A2) = 0.0003 f(A1) = 0.9800, f(A2) = 0.0200 f(A1) = 0.9604, f(A2) = 0.0392 f(A1) = 0.9700, f(A2) = 0.0300

f(A1) = 0.9700, f(A2) = 0.0300

The recessive allele that causes sickle cell anemia is harmful to homozygous individuals. What maintains the presence of this allele in a population's gene pool? stabilizing selection diploidy balancing selection heterozygote advantage

heterozygote advantage

Mutation is the only evolutionary mechanism that ________. decreases fitness is the ultimate source of variation in natural populations has no effect on genetic variation is more important in eukaryotes than in prokaryotes does little to change allele frequencies

is the ultimate source of variation in natural populations

Genetic variation ________. tends to be reduced by when diploid organisms produce gametes is created by the direct action of natural selection must be present in a population before natural selection can act upon the population arises in response to changes in the environment

must be present in a population before natural selection can act upon the population

For biologists studying a large flatworm population in the lab, which HardyWeinberg condition is most difficult to meet? no mutation random mating no gene flow no selection no genetic drift

no mutation

The mark-recapture method would be best for sampling a population of _____. The mark-recapture method would be best for sampling a population of _____. maple trees sharks oysters rose bushes wheat

sharks The mark-recapture method works best for active species whose individuals tend to be highly mobile.

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? directional selection artificial selection sexual selection stabilizing selection disruptive selection

stabilizing selection

Carrying capacity is _____. fixed for most species over most of their range most of the time seldom reached by marine producers and consumers because of the vast resources of the ocean the term used to describe the stress a population undergoes due to limited resources the maximum population size that a particular environment can support determined by density and dispersion data

the maximum population size that a particular environment can support