Skip to main content
Ch. 20 - Population Genetics and Evolution at the Population, Species, and Molecular Levels
Sanders - Genetic Analysis: An Integrated Approach 3rd Edition
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172당신이 사용하는 게 아니라요?교과서 변경
모든 교과서Sanders 3rd EditionCh. 20 - Population Genetics and Evolution at the Population, Species, and Molecular Levels문제 31a
20장, 문제 31a

Albinism, an autosomal recessive trait characterized by an absence of skin pigmentation, is found in 1 in 4000 people in populations at equilibrium. Brachydactyly, an autosomal dominant trait producing shortened fingers and toes, is found in 1 in 6000 people in populations at equilibrium. For each of these traits, calculate the frequency of the recessive allele at the locus

검증된 단계별 안내
1
Understand the problem: Albinism is an autosomal recessive trait, meaning individuals with the condition must have two copies of the recessive allele (aa). The frequency of individuals with albinism in the population is given as 1 in 4000. This corresponds to the genotype frequency of homozygous recessive individuals (q²). Similarly, for brachydactyly, an autosomal dominant trait, the frequency of affected individuals is 1 in 6000, which includes both heterozygous (Aa) and homozygous dominant (AA) genotypes.
For albinism, use the Hardy-Weinberg equation to calculate the frequency of the recessive allele (q). The Hardy-Weinberg equation is p² + 2pq + q² = 1, where p is the frequency of the dominant allele, q is the frequency of the recessive allele, p² is the frequency of homozygous dominant individuals, 2pq is the frequency of heterozygous individuals, and q² is the frequency of homozygous recessive individuals. Since q² = 1/4000, calculate q by taking the square root of q²: q = √(1/4000).
For brachydactyly, note that the frequency of affected individuals (1/6000) includes both heterozygous (2pq) and homozygous dominant (p²) genotypes. To calculate the frequency of the recessive allele (q), first determine the frequency of unaffected individuals (q²), which is the complement of the affected frequency: q² = 1 - (frequency of affected individuals). Then calculate q by taking the square root of q²: q = √q².
Once you have calculated q for both traits, you can also calculate the frequency of the dominant allele (p) using the relationship p + q = 1. Rearrange this equation to solve for p: p = 1 - q.
Summarize the results: The frequency of the recessive allele (q) for albinism and brachydactyly can be determined using the Hardy-Weinberg principle. Ensure that all calculations are consistent with the assumptions of Hardy-Weinberg equilibrium, such as random mating, no mutation, no migration, no selection, and a large population size.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
1m
도움이 되었나요?

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Hardy-Weinberg Principle

The Hardy-Weinberg Principle provides a mathematical framework for understanding allele frequencies in a population at genetic equilibrium. It states that allele and genotype frequencies will remain constant from generation to generation in the absence of evolutionary influences. This principle is essential for calculating allele frequencies, particularly in traits governed by simple Mendelian inheritance.
추천 영상:
가이드 코스
13:04
Hardy Weinberg

Autosomal Recessive Inheritance

Autosomal recessive inheritance occurs when a trait is expressed only when an individual has two copies of the recessive allele. In the case of albinism, the absence of skin pigmentation results from inheriting two recessive alleles. Understanding this inheritance pattern is crucial for calculating the frequency of the recessive allele in a population.
추천 영상:
가이드 코스
09:08
Autosomal Pedigrees

Allele Frequency Calculation

Allele frequency calculation involves determining the proportion of a specific allele within a population. For recessive traits, the frequency of the recessive allele can be derived from the proportion of individuals expressing the trait, using the formula q^2 = frequency of recessive phenotype. This calculation is vital for understanding genetic variation and predicting the likelihood of traits in future generations.
추천 영상:
가이드 코스
03:03
New Alleles and Migration
관련 실천
교과서 질문

In humans the presence of chin and cheek dimples is dominant to the absence of dimples, and the ability to taste the compound PTC is dominant to the inability to taste the compound. Both traits are autosomal, and they are unlinked. The frequencies of alleles for dimples are D = 0.62 and d = 0.38. For tasting, the allele frequencies are T = 0.76 and t = 0.24.

What are the expected frequencies of the four possible phenotype combinations: dimpled tasters, undimpled tasters, dimpled nontasters, and undimpled nontasters?

472
views
교과서 질문

A sample of 500 field mice contains 225 individuals that are D₁D₁, 175 that are D₁D₂, and 100 that are D₂D₂.

Is inbreeding a possible genetic explanation for the observed distribution of genotypes? Why or why not?

621
views
교과서 질문

In humans the presence of chin and cheek dimples is dominant to the absence of dimples, and the ability to taste the compound PTC is dominant to the inability to taste the compound. Both traits are autosomal, and they are unlinked. The frequencies of alleles for dimples are D = 0.62 and d = 0.38. For tasting, the allele frequencies are T = 0.76 and t = 0.24.

Determine the frequency of genotypes for each gene and the frequency of each phenotype.

524
views
교과서 질문

Albinism, an autosomal recessive trait characterized by an absence of skin pigmentation, is found in 1 in 4000 people in populations at equilibrium. Brachydactyly, an autosomal dominant trait producing shortened fingers and toes, is found in 1 in 6000 people in populations at equilibrium. For each of these traits, calculate the frequency of heterozygotes in the population

821
views
교과서 질문

Albinism, an autosomal recessive trait characterized by an absence of skin pigmentation, is found in 1 in 4000 people in populations at equilibrium. Brachydactyly, an autosomal dominant trait producing shortened fingers and toes, is found in 1 in 6000 people in populations at equilibrium. For each of these traits, calculate the frequency of For albinism only, what is the frequency of mating between heterozygotes?

1056
views
교과서 질문

Albinism, an autosomal recessive trait characterized by an absence of skin pigmentation, is found in 1 in 4000 people in populations at equilibrium. Brachydactyly, an autosomal dominant trait producing shortened fingers and toes, is found in 1 in 6000 people in populations at equilibrium. For each of these traits, calculate the frequency of the dominant allele at the locus

854
views