Understanding Hardy-Weinberg Assumptions and Calculations - AP Biology
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Which of the following is NOT an assumption required for Hardy-Weinberg equilibrium?
Which of the following is NOT an assumption required for Hardy-Weinberg equilibrium?
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Hardy-Weinberg states that for a population to be in equilibrium, it must not be experiencing migration, genetic drift, mutation, or selection. By this definition, population size cannot fluctuate.
Hardy-Weinberg states that for a population to be in equilibrium, it must not be experiencing migration, genetic drift, mutation, or selection. By this definition, population size cannot fluctuate.
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According to Hardy-Weinberg calculations, a population's allele frequency will remain the same from generation to generation as long as evolution is not occurring. There are five conditions that must be met for equilibrium to remain in effect in a population.
Which of the following is not a condition for Hardy-Weinberg equilibrium to remain in effect?
According to Hardy-Weinberg calculations, a population's allele frequency will remain the same from generation to generation as long as evolution is not occurring. There are five conditions that must be met for equilibrium to remain in effect in a population.
Which of the following is not a condition for Hardy-Weinberg equilibrium to remain in effect?
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Random mating must occur in the population in order for the equilibrium to remain. If nonrandom mating occurred, allele frequency in the population would change. The alleles frequency of those mating the most would increase, while that of those mating less would decrease.
Large populations must be used to minimize the effects of genetic drift. Mustations cannot occur, as these could introduce new alleles.
It is important to note that no natural populations exist in Hardy-Weinberg equilibrium. This is simply a theoretical tool.
Random mating must occur in the population in order for the equilibrium to remain. If nonrandom mating occurred, allele frequency in the population would change. The alleles frequency of those mating the most would increase, while that of those mating less would decrease.
Large populations must be used to minimize the effects of genetic drift. Mustations cannot occur, as these could introduce new alleles.
It is important to note that no natural populations exist in Hardy-Weinberg equilibrium. This is simply a theoretical tool.
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Imagine that a population is in Hardy-Weinberg equilibrium. A certain gene presents as two different alleles, and 49% of the population is homozygous dominant.
What percentage of the population is homozygous recessive?
Imagine that a population is in Hardy-Weinberg equilibrium. A certain gene presents as two different alleles, and 49% of the population is homozygous dominant.
What percentage of the population is homozygous recessive?
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When a population is in Hardy-Weinberg equilibrium, we can quantitatively determine how the alleles are distributed in the population. P2 is equal to the proprtion of the population that is homozygous dominant based on the equation p2 + 2pq + q2 = 1. We also know that p + q = 1.
Since P2 = 0.49 in this case, we know that p is equal to 0.7. Since there are only two alleles for this gene, we know that the other allele, q in this case, is 0.3. Since homozygous recessive is referred to as q2 in the equation, we can plug in the value of 0.3 and determine that q2 = 0.09. As a result, we confirm that 9% of the population is homozygous recessive.
When a population is in Hardy-Weinberg equilibrium, we can quantitatively determine how the alleles are distributed in the population. P2 is equal to the proprtion of the population that is homozygous dominant based on the equation p2 + 2pq + q2 = 1. We also know that p + q = 1.
Since P2 = 0.49 in this case, we know that p is equal to 0.7. Since there are only two alleles for this gene, we know that the other allele, q in this case, is 0.3. Since homozygous recessive is referred to as q2 in the equation, we can plug in the value of 0.3 and determine that q2 = 0.09. As a result, we confirm that 9% of the population is homozygous recessive.
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Which of the following is a Hardy-Weinberg assumption?
Which of the following is a Hardy-Weinberg assumption?
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Random mating is one of the five Hardy-Weinberg assumptions that help maintain equilibrium. If random mating occurs, in tandem with the other assumptions, we can reasonably assume that there will not be a shift in allele frequencies or distributions.
The other Hardy-Weinberg assumptions are that natural selection does not occur, mutation does not occur, genetic drift (gene flow) does not occur, and that the population size is large.
Random mating is one of the five Hardy-Weinberg assumptions that help maintain equilibrium. If random mating occurs, in tandem with the other assumptions, we can reasonably assume that there will not be a shift in allele frequencies or distributions.
The other Hardy-Weinberg assumptions are that natural selection does not occur, mutation does not occur, genetic drift (gene flow) does not occur, and that the population size is large.
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If four percent of the population is homozygous recessive for the trait that carries dimples (recessive), what is the fractional frequency of the dominant allele?
If four percent of the population is homozygous recessive for the trait that carries dimples (recessive), what is the fractional frequency of the dominant allele?
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Using the Hardy-Weinberg law to solve for allele frequency in populations, you can solve for the answer using the following two equations.
p is the fractional frequency of the dominant allele, q is the fractional frequency of the recessive allele, and q2 is the fraction of the population that is homozygous recessive. q2 is given in the question to be 0.04 (or 4%).
Using the Hardy-Weinberg law to solve for allele frequency in populations, you can solve for the answer using the following two equations.
p is the fractional frequency of the dominant allele, q is the fractional frequency of the recessive allele, and q2 is the fraction of the population that is homozygous recessive. q2 is given in the question to be 0.04 (or 4%).
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In a population of fruit flies, the allele for red eyes is dominant to the allele for white eyes. If 50% the population is heterozygous and 25% is homozygous for white eyes, what is the frequency of the allele for red eyes?
In a population of fruit flies, the allele for red eyes is dominant to the allele for white eyes. If 50% the population is heterozygous and 25% is homozygous for white eyes, what is the frequency of the allele for red eyes?
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We must remember our two equations for allele frequency, according to Hardy-Weinberg equilibrium.
We know that, in the first equation, each term represents a total percentage of homozygotes or heterozygotes. 
represents the allele for red eyes and 
represents white.
Using the information from the question, we can solve for 
and 
.
The frequency of each allele is 0.50.
We must remember our two equations for allele frequency, according to Hardy-Weinberg equilibrium.
We know that, in the first equation, each term represents a total percentage of homozygotes or heterozygotes.
Using the information from the question, we can solve for
The frequency of each allele is 0.50.
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The allele frequencies for a population displaying Hardy-Weinberg equilibrium were found to be 
dominant and 
recessive. What percentage of the population is homozygous dominant?
The allele frequencies for a population displaying Hardy-Weinberg equilibrium were found to be
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For this question we are going to need to make use of the Hardy-Weinberg equilibrium equations. The equation we need to use is:
These numbers represent the percentages of each genotype found in a given population. We were given the values of 
and 
in the question.
After plugging the numbers into the equation, we can find the value of 
. This value will give us the frequency of homozygous dominant individuals.
For this question we are going to need to make use of the Hardy-Weinberg equilibrium equations. The equation we need to use is:
These numbers represent the percentages of each genotype found in a given population. We were given the values of
After plugging the numbers into the equation, we can find the value of
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Eye color in a certain species is decided by a single gene locus. Only two alleles influence eye color in a population of this species that exists in Hardy-Weinberg equilibrium. The dominant allele codes for brown eyes, while the recessive allele codes for blue eyes.
If the frequency of the brown allele is 
, what percent of the population is heterozygous at this locus?
Eye color in a certain species is decided by a single gene locus. Only two alleles influence eye color in a population of this species that exists in Hardy-Weinberg equilibrium. The dominant allele codes for brown eyes, while the recessive allele codes for blue eyes.
If the frequency of the brown allele is
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For problems of this type, we need to understand the Hardy-Weinberg equations:
Here, 
represents the frequency of the dominant allele, while c refers to the frequency of the recessive allele. 
and 
denote the proportion of homozygous dominant and recessive phenotypes, respectively. Finally, the proportion of heterozygotes is denoted by 
.
We already know that 
, and if only two alleles are present in the population, 
must be equal to 
.
Using the values for 
and 
, we can solve for the proportion of heterozygotes using the 
term of the Hardy-Weinberg equation.
For problems of this type, we need to understand the Hardy-Weinberg equations:
Here,
We already know that
Using the values for
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A population of snails is originally in Hardy-Weinberg equilibrium. The snails come in two different colors: red, the dominant phenotype, and white, the recessive phenotype. The original population has a dominant allele frequency of 
and a recessive allele frequency of 
. A new predator is introduced to the habitat that is particularly fond of the red snails. After a few years the dominant allele frequency has been reduced to 
.
What is the recessive allele frequency after the introduction of this predator?
A population of snails is originally in Hardy-Weinberg equilibrium. The snails come in two different colors: red, the dominant phenotype, and white, the recessive phenotype. The original population has a dominant allele frequency of
What is the recessive allele frequency after the introduction of this predator?
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Most of the information in the question is actually superfluous because we are given the final dominant allele frequency. The dominant allele frequency corresponds to the variable 
in the Hardy-Weinberg equations.
The question tells us that the dominant allele frequency after introduction of the predator is 
. Use this value in the first Hardy-Weinberg equation to solve for the recessive allele frequency, 
.
Most of the information in the question is actually superfluous because we are given the final dominant allele frequency. The dominant allele frequency corresponds to the variable
The question tells us that the dominant allele frequency after introduction of the predator is
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A population of snails is in Hardy-Weinberg equilibrium. The snails come in two different colors: red, the dominant phenotype, and white, the recessive phenotype. The population consists of sixty-four red snails and thirty-six white snails.
Assuming that the population is in Hardy-Weinberg equilibrium, what is the value of 
?
A population of snails is in Hardy-Weinberg equilibrium. The snails come in two different colors: red, the dominant phenotype, and white, the recessive phenotype. The population consists of sixty-four red snails and thirty-six white snails.
Assuming that the population is in Hardy-Weinberg equilibrium, what is the value of
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We can solve this question using the Hardy-Weinberg equations:
is equal to the recessive allele frequency, while 
in the second Hardy-Weinberg equation corresponds to the frequency of the recessive phenotype.
The question tells us the number of dominant red snails and the number of recessive white snails. Using these values, we can find the frequency of the recessive phenotype.
From here, take the square root to find the value of 
.
We can solve this question using the Hardy-Weinberg equations:
The question tells us the number of dominant red snails and the number of recessive white snails. Using these values, we can find the frequency of the recessive phenotype.
From here, take the square root to find the value of
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A population of snails is in Hardy-Weinberg equilibrium. The snails come in two different colors: red, the dominant phenotype, and white, the recessive phenotype. There are sixteen homozygous dominant, forty-eight heterozygous, and thirty-six homozygous recessive snails.
What are the allele frequencies for this population?
A population of snails is in Hardy-Weinberg equilibrium. The snails come in two different colors: red, the dominant phenotype, and white, the recessive phenotype. There are sixteen homozygous dominant, forty-eight heterozygous, and thirty-six homozygous recessive snails.
What are the allele frequencies for this population?
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We can solve this question using the Hardy-Weinberg equations:
In the second equation, 
corresponds to the frequency of homozygous dominant individuals, 
corresponds to the heterozygous frequency, and 
corresponds to the frequency of homozygous recessive individuals. We are given enough information to find each of these values from the question.
We can find the values of 
and 
by taking the square root of their squares.
We can solve this question using the Hardy-Weinberg equations:
In the second equation,
We can find the values of
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A population is in Hardy-Weinberg equilibrium. In the population, 1% of individuals show the recessive trait for blue eyes. What is the value of 
in this situation?
A population is in Hardy-Weinberg equilibrium. In the population, 1% of individuals show the recessive trait for blue eyes. What is the value of
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For a population in Hardy-Weinberg equilibrium, every trait follows the equations:
In these formulas, 
represents the frequency of the dominant allele and 
represents the frequency of the recessive allele. 
represents the frequency of the homozygous dominant genotype, 
represents the frequency of the heterozygous genotype, and 
represents the frequency of the homozygous recessive genotype.
In this case, the individuals with blue eyes would be represented by the homozygous recessive genotype. Using this data, we can solve for the frequency of the recessive allele.
Use the frequency of the recessive allele to find the frequency of the dominant allele, 
.
For a population in Hardy-Weinberg equilibrium, every trait follows the equations:
In these formulas,
In this case, the individuals with blue eyes would be represented by the homozygous recessive genotype. Using this data, we can solve for the frequency of the recessive allele.
Use the frequency of the recessive allele to find the frequency of the dominant allele,
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A population of beetles exists in which black coloration is dominant to white. If there are 64 black beetles in the population, what is the dominant allele frequency?
A population of beetles exists in which black coloration is dominant to white. If there are 64 black beetles in the population, what is the dominant allele frequency?
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It is impossible to determine the allele frequency from the given information.
The problem only tells the number of black beetles, but does not give any information that would allow us to find the total number of beetles in the population. We do not have the homozygous recessive population or the distribution of heterozygotes and homozygous dominant beetles. Given information on the number of white beetles would allow us to calculate the recessive allele frequency, and subsequently the dominant allele frequency.
It is impossible to determine the allele frequency from the given information.
The problem only tells the number of black beetles, but does not give any information that would allow us to find the total number of beetles in the population. We do not have the homozygous recessive population or the distribution of heterozygotes and homozygous dominant beetles. Given information on the number of white beetles would allow us to calculate the recessive allele frequency, and subsequently the dominant allele frequency.
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Which of the following is not a Hardy-Weinberg assumption?
Which of the following is not a Hardy-Weinberg assumption?
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One of the five main assumptions is that mutations are negligible. This makes sense because, if a population is in Hardy-Weinberg equilibrium, evolution is not occurring. A low rate of mutations would help keep a population in equilibrium.
The five assumptions of Hardy-Weinberg equilibrium are a large population size, no natural selection, no mutation rate, no genetic drift, and random mating.
One of the five main assumptions is that mutations are negligible. This makes sense because, if a population is in Hardy-Weinberg equilibrium, evolution is not occurring. A low rate of mutations would help keep a population in equilibrium.
The five assumptions of Hardy-Weinberg equilibrium are a large population size, no natural selection, no mutation rate, no genetic drift, and random mating.
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A population of beetles exists in which black coloration is dominant to white. If there are 36 white beetles in a population of 100 beetles, what is the dominant allele frequency?
A population of beetles exists in which black coloration is dominant to white. If there are 36 white beetles in a population of 100 beetles, what is the dominant allele frequency?
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There are multiple ways to solve this problem, but the easiest is to use the Hardy-Weinberg equations:
We are told the frequency of white beetles in the population. Using this value, we can find the recessive allele frequency. 
is equivalent to the homozygous recessive genotype frequency.
Use this value to solve for the dominant allele frequency.
There are multiple ways to solve this problem, but the easiest is to use the Hardy-Weinberg equations:
We are told the frequency of white beetles in the population. Using this value, we can find the recessive allele frequency.
Use this value to solve for the dominant allele frequency.
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A population is in Hardy-Weinberg equilibrium. The gene of interest has two alleles, with 16% of the population portraying the features of the recessive phenotype. What percentage of the population is heterozygous?
A population is in Hardy-Weinberg equilibrium. The gene of interest has two alleles, with 16% of the population portraying the features of the recessive phenotype. What percentage of the population is heterozygous?
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Using the Hardy-Weinberg equilibrium equations, you can determine the answer.
The value of 
gives us the frequency of the dominant allele, while the value of 
gives us the frequency of the recessive allele. The second equation corresponds to genotypes. 
is the homozygous dominant frequency, 
is the heterozygous frequency, and 
is the homozygous recessive frequency.
16% of the population shows the recessive phenotype, and therefore must carry the homozygous recessive genotype. We can use this information to solve for the recessive allele frequency.
We can use the value of 
and the first Hardy-Weinberg equation to solve for 
.
Knowing both 
and 
, you can use the second equation to find the percent of heterozygous organisms in the population.
Using the Hardy-Weinberg equilibrium equations, you can determine the answer.
The value of
16% of the population shows the recessive phenotype, and therefore must carry the homozygous recessive genotype. We can use this information to solve for the recessive allele frequency.
We can use the value of
Knowing both
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Hearing loss is caused by the inheritance of different genetic alleles: GM and GJ. The expected frequency of a GM allele is 90% in a given population.
Based on the Hardy-Weinberg principle, what is the expected frequency of genotype GMGJ in the next generation of this population?
Hearing loss is caused by the inheritance of different genetic alleles: GM and GJ. The expected frequency of a GM allele is 90% in a given population.
Based on the Hardy-Weinberg principle, what is the expected frequency of genotype GMGJ in the next generation of this population?
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The Hardy-Weinberg equations can be used to determine the expected frequency of genes and genotypes within a population, provided that only Mendelian segregation and recombination of alleles are at work. This is calculated mathematically using the equations:
In this example, the expected frequency to be solved for is the heterozygote GMGJ that is represented by the 
component of the equation. We are told the frequency of the GM allele in the population, allowing us to solve for the frequency of the GJ allele. It is not necessary to know which allele is dominant and which is recessive in this particular question since we are dealing only with genotypes (phenotype is irrelevant).
Using these values, we can calculate the value of 
.
The Hardy-Weinberg equations can be used to determine the expected frequency of genes and genotypes within a population, provided that only Mendelian segregation and recombination of alleles are at work. This is calculated mathematically using the equations:
In this example, the expected frequency to be solved for is the heterozygote GMGJ that is represented by the
Using these values, we can calculate the value of
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A person carrying two recessive alleles of a specific gene has a greater likelihood of developing lung cancer. The frequency of the dominant allele in a population is eighty-seven percent.
Based on the Hardy-Weinberg principle, what is the expected frequency of homozygous recessive genotype in this population?
A person carrying two recessive alleles of a specific gene has a greater likelihood of developing lung cancer. The frequency of the dominant allele in a population is eighty-seven percent.
Based on the Hardy-Weinberg principle, what is the expected frequency of homozygous recessive genotype in this population?
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The Hardy-Weinberg equations can be used to determine the expected frequency of genes and genotypes within a population, provided that only Mendelian segregation and recombination of alleles are at work. This is calculated mathematically using the equations:
Let's start with what we know and how it relates to these equations. We are told that the dominant allele frequency (
) is 87%, and then asked to find the frequency of homozygous recessive individuals (
).
Known: 
Unknown: 
Use the second Hardy-Weinberg equation to solve for 
.
Square this value for find the frequency of homozygous individuals.
The Hardy-Weinberg equations can be used to determine the expected frequency of genes and genotypes within a population, provided that only Mendelian segregation and recombination of alleles are at work. This is calculated mathematically using the equations:
Let's start with what we know and how it relates to these equations. We are told that the dominant allele frequency (
Known:
Unknown:
Use the second Hardy-Weinberg equation to solve for
Square this value for find the frequency of homozygous individuals.
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A variety of grapes possesses a gene that generally determines the size of fruit produced. In a population of 200 plants, 194 show the dominant phenotype.
Based on the Hardy-Weinberg principles, what is the expected frequency of the dominant allele in this population?
A variety of grapes possesses a gene that generally determines the size of fruit produced. In a population of 200 plants, 194 show the dominant phenotype.
Based on the Hardy-Weinberg principles, what is the expected frequency of the dominant allele in this population?
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The Hardy-Weinberg equations can be used to determine the expected frequency of genes and genotypes within a population, provided that only Mendelian segregation and recombination of alleles are at work. This is calculated mathematically using the equations:
We are told that 194 plants in a population of 200 demonstrate the dominant phenotype. This means that the sum of the homozygous dominant and heterozygous individuals is represented by the 194 plants described.
So, 97% of the plants show the dominant phenotype. This means that 3% must show the recessive phenotype.
Using this, we can find the frequency of the recessive allele, 
, and subsequently the dominant allele, 
.
The Hardy-Weinberg equations can be used to determine the expected frequency of genes and genotypes within a population, provided that only Mendelian segregation and recombination of alleles are at work. This is calculated mathematically using the equations:
We are told that 194 plants in a population of 200 demonstrate the dominant phenotype. This means that the sum of the homozygous dominant and heterozygous individuals is represented by the 194 plants described.
So, 97% of the plants show the dominant phenotype. This means that 3% must show the recessive phenotype.
Using this, we can find the frequency of the recessive allele,
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In a given population of snails, spiral shells are dominant to round shells. If 36% of the population is homozygous for the spiral shell allele, what percentage of the population is heterozygous?
In a given population of snails, spiral shells are dominant to round shells. If 36% of the population is homozygous for the spiral shell allele, what percentage of the population is heterozygous?
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We can use the Hardy-Weinberg equations to solve this problem.
We know that spiral shells are dominant, and that 36% of the population is homozygous for the spiral allele. This tells us that 36% of the population is homozygous dominant. The 
term corresponds to the homozygous dominant percentage.
is the dominant allele frequency. Now we can solve for 
, the recessive allele frequency.
The term 
will give us the frequency of heterozygotes.
48% of the population is heterozygous.
We can use the Hardy-Weinberg equations to solve this problem.
We know that spiral shells are dominant, and that 36% of the population is homozygous for the spiral allele. This tells us that 36% of the population is homozygous dominant. The
The term
48% of the population is heterozygous.
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