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Questions and Answers
What does the letter 'p' represent in this population analysis?
What does the letter 'p' represent in this population analysis?
The frequency of the homozygous recessive genotype (oo) in the chicken population is 0.16.
The frequency of the homozygous recessive genotype (oo) in the chicken population is 0.16.
True
What is the value of 'q' in the chicken population's genotypic frequencies?
What is the value of 'q' in the chicken population's genotypic frequencies?
0.4
The predicted genotypic frequencies can be calculated using the equation p + ___ + q^2 = 1.
The predicted genotypic frequencies can be calculated using the equation p + ___ + q^2 = 1.
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Match the following genotypes with their descriptions:
Match the following genotypes with their descriptions:
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If the actual genotypic frequencies differ from the predicted values, what might a scientist conclude?
If the actual genotypic frequencies differ from the predicted values, what might a scientist conclude?
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The frequency of the dominant phenotype (blue eggs) is greater than that of the recessive phenotype (white eggs).
The frequency of the dominant phenotype (blue eggs) is greater than that of the recessive phenotype (white eggs).
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What is the predicted frequency of heterozygous chickens (Oo)?
What is the predicted frequency of heterozygous chickens (Oo)?
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What type of selection occurs when extreme phenotypes are selected against?
What type of selection occurs when extreme phenotypes are selected against?
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Individuals with very low or very high birth weights tend to have higher survival rates compared to those of average birth weight.
Individuals with very low or very high birth weights tend to have higher survival rates compared to those of average birth weight.
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What was observed about the peppered moth population before and after the Industrial Revolution?
What was observed about the peppered moth population before and after the Industrial Revolution?
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In stabilizing selection, phenotypes near the ______ are selected for.
In stabilizing selection, phenotypes near the ______ are selected for.
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Match the following moth coloration with its population trend:
Match the following moth coloration with its population trend:
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What was the main factor causing the change in moth populations in the mentioned example?
What was the main factor causing the change in moth populations in the mentioned example?
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Directional selection favors a shift in phenotypic traits toward one extreme.
Directional selection favors a shift in phenotypic traits toward one extreme.
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What effect does stabilizing selection have on the frequency of extreme phenotypes over time?
What effect does stabilizing selection have on the frequency of extreme phenotypes over time?
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What type of natural selection is observed in peppered moths during the Industrial Revolution?
What type of natural selection is observed in peppered moths during the Industrial Revolution?
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Directional selection favors both extremes of a phenotype equally.
Directional selection favors both extremes of a phenotype equally.
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Which phenotype became more advantageous for the peppered moths during the Industrial Revolution?
Which phenotype became more advantageous for the peppered moths during the Industrial Revolution?
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In directional selection, the frequency of the ______ phenotype increases over time.
In directional selection, the frequency of the ______ phenotype increases over time.
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In lace bunting males, which feather color is observed as the most successful?
In lace bunting males, which feather color is observed as the most successful?
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Dull brown male lazuli buntings are often displaced by the brighter males during mating.
Dull brown male lazuli buntings are often displaced by the brighter males during mating.
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The mean value of a trait in directional selection shifts towards the ______ phenotype.
The mean value of a trait in directional selection shifts towards the ______ phenotype.
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Match the following terms with their definitions:
Match the following terms with their definitions:
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What caused the initial change in genetic variation in the northern elephant seal population?
What caused the initial change in genetic variation in the northern elephant seal population?
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The genetic drift can cause some alleles to become fixed in the population.
The genetic drift can cause some alleles to become fixed in the population.
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What is meant by the term 'bottleneck effect' in genetics?
What is meant by the term 'bottleneck effect' in genetics?
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The loss of genetic diversity due to a drastic reduction in population size is known as the ______ effect.
The loss of genetic diversity due to a drastic reduction in population size is known as the ______ effect.
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What was the population status of the northern elephant seal in the 1890s?
What was the population status of the northern elephant seal in the 1890s?
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Match the terms with their descriptions:
Match the terms with their descriptions:
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The population of northern elephant seals has rebounded to its original diversity levels since the bottleneck event.
The population of northern elephant seals has rebounded to its original diversity levels since the bottleneck event.
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Describe how genetic drift affects a population's gene pool.
Describe how genetic drift affects a population's gene pool.
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What is the expected outcome for male widowbirds as they mate with longer-tailed males?
What is the expected outcome for male widowbirds as they mate with longer-tailed males?
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In a population of 900 pea plants, there are 530 homozygous purple individuals.
In a population of 900 pea plants, there are 530 homozygous purple individuals.
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What is the total number of alleles in a population of 900 pea plants?
What is the total number of alleles in a population of 900 pea plants?
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The dominant allele for color in pea plants is represented by the letter ______.
The dominant allele for color in pea plants is represented by the letter ______.
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What best describes the allele frequency of 'p' in the described population?
What best describes the allele frequency of 'p' in the described population?
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The ______ effect can lead to a decrease in genetic variation in populations.
The ______ effect can lead to a decrease in genetic variation in populations.
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Match the genetic terms with their appropriate description:
Match the genetic terms with their appropriate description:
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Surviving individuals reproduce after a random event acts on a population in the bottleneck effect.
Surviving individuals reproduce after a random event acts on a population in the bottleneck effect.
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What type of selection is indicated by the gradual change in color traits among a rabbit population in mountainous areas?
What type of selection is indicated by the gradual change in color traits among a rabbit population in mountainous areas?
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Stabilizing selection occurs when extreme traits are favored in a population.
Stabilizing selection occurs when extreme traits are favored in a population.
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How would the trait of finger length evolve in a population of monkeys with thicker tree branches?
How would the trait of finger length evolve in a population of monkeys with thicker tree branches?
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A population of rabbits experiencing changes in color traits is an example of __________ selection.
A population of rabbits experiencing changes in color traits is an example of __________ selection.
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Match the following concepts with their definitions:
Match the following concepts with their definitions:
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What likely occurred in the population of Florida panthers when they mated with other subspecies?
What likely occurred in the population of Florida panthers when they mated with other subspecies?
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Disruptive selection promotes the survival of individuals with average traits.
Disruptive selection promotes the survival of individuals with average traits.
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What is one indication that evolution is occurring in a population?
What is one indication that evolution is occurring in a population?
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Study Notes
Evolution of Populations
- Ruffs are birds found in Europe and Asia, living in marshes and mudflats.
- During breeding season, males engage in "fights" to attract females.
- Three male types exist: independents, satellites, and faeders.
- Independents are largest, fight for territory, and have dark feathers.
- Satellites are smaller, with white neck feathers, and move between territories.
- Faeders resemble females, and mate with females when others are distracted.
- About 84% of male ruffs are independent.
Genetic Variation
- Meerkats live in cooperative groups in African deserts.
- Traits show variation in size, underside color, facial markings, etc.
- Phenotypic variation is due to differences in genes.
- Advantageous traits increase survival and reproductive success.
- Natural selection favors traits that improve survival/reproduction.
- Gene pool is the collection of alleles in a population.
- Mutations during meiosis create variations in alleles.
Variation in Alleles
- Alleles are different forms of a gene.
- Mice with brown fur have a dominant B allele; black fur has a recessive b allele.
- Allele frequency is the ratio of a specific allele to all alleles.
- Allele frequency is calculated by dividing the number of specific alleles by the total number of alleles.
- Changes in allele frequency can be measured and tracked in a population.
Analyzing Population Evolution
- Some bird species, like chickens, have eggshells that can be white or blue.
- Blue eggshells are dominant (coded by allele O), and white is recessive (coded by allele o).
- Punnett squares can predict possible offspring genotypes from the cross between two heterozygous parents.
Data Analysis
- Analyzing data from a population helps scientists understand which allele frequencies they observed.
- Scientists may compare observed values with predicted values using Hardy-Weinberg equations in a population.
Cause and Effect
- Hardy-Weinberg equilibrium describes a stable, non-evolving population.
- Five conditions are necessary for equilibrium: no mutations, a large population, no natural selection, no gene flow, and random mating.
Selection on Populations
- King Penguins have traits varying in size, beak lengths, beak shapes.
- The graph of these traits shows a normal distribution: most traits fall near the average, with fewer extreme values.
- Traits further from the average are less common.
Stabilizing Selection
- Intermediate phenotypes are favored over extreme phenotypes in stabilizing selection.
- Examples include human birth weight, where extreme low or high weights have lower survival rates.
Directional Selection
- In directional selection, one extreme phenotype is favored, shifting the average towards that extreme.
- Peppered moths exhibit this, where dark moths increased in frequency during periods of industrial pollution.
Disruptive Selection
- In disruptive selection, both extreme phenotypes are favored, while intermediate forms are selected against.
- This may result when certain environments create different adaptive advantages, for example, the color features of the male lazuli bunting birds.
Effects of Gene Flow
- Gene flow is the movement of alleles between populations.
- Examples include pollen transfer between plants or migration of animals.
Genetic Drift
- Genetic drift is a change in allele frequencies due to chance events.
- Smaller populations are more affected by these chance events.
- Bottleneck effect occurs when the population drastically reduces in size.
- Founder effect occurs when a small group of individuals establishes a new population, potentially with different allele frequencies than the original.
Sexual Selection
- Sexual selection occurs when certain traits increase reproductive success.
- Intrasexual selection involves competition among males for mating opportunities.
- Intersexual selection involves females choosing males with specific traits.
- The process of selection and reproduction is driven by nature and populations change to improve their evolutionary chances of success.
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Description
Explore the fascinating dynamics of how populations evolve through genetic variation. This quiz covers the breeding behaviors of ruffs, the traits of meerkats, and the principles of natural selection. Test your knowledge of these concepts and their implications in biology.
