Ch. 2 - Transmission Genetics

Sanders - Genetic Analysis: An Integrated Approach 3rd Edition

Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172당신이 사용하는 게 아니라요?교과서 변경

Sanders 3rd Edition

Ch. 2 - Transmission Genetics

문제 16c

2장, 문제 16c

A geneticist crosses a pure-breeding strain of peas producing yellow, wrinkled seeds with one that is pure-breeding for green, round seeds.
What is the expected phenotype distribution among the F₂ progeny?

검증된 단계별 안내

Step 1: Identify the traits and their inheritance patterns. Yellow and green seed color are determined by one gene, and round and wrinkled seed shape are determined by another gene. Assume that yellow (Y) is dominant to green (y), and round (R) is dominant to wrinkled (r).

Step 2: Determine the genotype of the parental strains. The pure-breeding yellow, wrinkled strain will have the genotype YYrr, and the pure-breeding green, round strain will have the genotype yyRR.

Step 3: Perform a Punnett square for the F₁ generation. Cross YYrr with yyRR. The F₁ progeny will all have the genotype YyRr, which is heterozygous for both traits. Their phenotype will be yellow and round due to dominance.

Step 4: Perform a dihybrid cross for the F₂ generation. Cross two F₁ individuals (YyRr × YyRr). Use a 4x4 Punnett square to determine all possible combinations of alleles for the F₂ progeny. Each parent contributes one allele for each gene.

Step 5: Analyze the results of the dihybrid cross. The expected phenotype ratio among the F₂ progeny will follow Mendel's law of independent assortment, resulting in a 9:3:3:1 ratio: 9 yellow round, 3 yellow wrinkled, 3 green round, and 1 green wrinkled.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

주요 개념

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

Mendelian Genetics

Mendelian genetics is the study of how traits are inherited through generations, based on the principles established by Gregor Mendel. It involves understanding dominant and recessive alleles, where dominant traits mask the expression of recessive ones. In this case, yellow seeds (Y) are dominant over green seeds (y), and round seeds (R) are dominant over wrinkled seeds (r).

Punnett Square

A Punnett square is a diagram used to predict the genotypic and phenotypic outcomes of a genetic cross. By organizing the alleles from each parent, it allows for the visualization of potential combinations in the offspring. For the given cross, the Punnett square will help determine the expected ratios of yellow, green, round, and wrinkled seeds in the F₂ generation.

Phenotypic Ratio

The phenotypic ratio refers to the relative frequency of different phenotypes in the offspring resulting from a genetic cross. In this scenario, the expected phenotypic ratio among the F₂ progeny can be derived from the combinations of alleles produced in the Punnett square. For a dihybrid cross like this, the typical ratio is 9:3:3:1 for the four possible phenotypes.

관련 실천

교과서 질문

Suppose an F₁ dihybrid (round yellow plant from Problem 16) is crossed to the pure-breeding green, round parental strain. Use a forked-line diagram to predict the phenotypic distribution of the resulting progeny.

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교과서 질문

A geneticist crosses a pure-breeding strain of peas producing yellow, wrinkled seeds with one that is pure-breeding for green, round seeds.

What proportion of the F₂ progeny are expected to have yellow seeds? Wrinkled seeds? Green seeds? Round seeds?

582

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교과서 질문

The accompanying pedigree shows the transmission of albinism (absence of skin pigment) in a human family.

One child of female I-3 has albinism. What is the probability that any of the other four children are carriers of the allele for albinism?

894

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교과서 질문

In pea plants, the appearance of flowers along the main stem is a dominant phenotype called 'axial' and is controlled by an allele T. The recessive phenotype, produced by an allele t, has flowers only at the end of the stem and is called 'terminal.' Pod form displays a dominant phenotype, 'inflated,' controlled by an allele C, and a recessive 'constricted' form, produced by the c allele. A cross is made between a pure-breeding axial, constricted plant and a plant that is pure-breeding terminal, inflated.

The F₁ progeny of this cross are allowed to self-fertilize. What is the expected phenotypic distribution among the F₂ progeny?

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교과서 질문

Suppose that all of the F₂ progeny with terminal flowers, i.e., plants with terminal flowers and inflated pods and plants with terminal flowers and constricted pods, are saved and allowed to self-fertilize to produce a partial F₃ generation. What is the expected phenotypic distribution among these F₃ plants?

611

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교과서 질문

A geneticist crosses a pure-breeding strain of peas producing yellow, wrinkled seeds with one that is pure-breeding for green, round seeds.

Use a Punnett square to predict the F₂ progeny that would be expected if the F₁ are allowed to self-fertilize.

563

views

A geneticist crosses a pure-breeding strain of peas producing yellow, wrinkled seeds with one that is pure-breeding for green, round seeds.What is the expected phenotype distribution among the F₂ progeny?

비슷한 문제에 대한 검증된 영상 답변:

주요 개념

Mendelian Genetics

Punnett Square

Phenotypic Ratio

A geneticist crosses a pure-breeding strain of peas producing yellow, wrinkled seeds with one that is pure-breeding for green, round seeds.
What is the expected phenotype distribution among the F₂ progeny?