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Ch. 2 - Transmission Genetics
Sanders - Genetic Analysis: An Integrated Approach 3rd Edition
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172Not the one you use?Change textbook
Chapter 2, Problem 48d

A pea plant that has the genotype RrGgwwdd is crossed to a plant that has the rrGgWwDd genotype. The R gene controls round versus wrinkled seed, the G gene controls yellow versus green seed, the W gene controls purple versus white flower, and the D gene controls tall versus short plants. Determine the following:
What proportion of the progeny are expected to be round, yellow, purple, and tall?

Verified step by step guidance
1
Step 1: Identify the genotypes of the parents and the traits they control. Parent 1 has the genotype RrGgwwdd, and Parent 2 has the genotype rrGgWwDd. The traits controlled by the genes are: R (round vs wrinkled seed), G (yellow vs green seed), W (purple vs white flower), and D (tall vs short plants).
Step 2: Determine the possible gametes for each parent. For Parent 1 (RrGgwwdd), the possible gametes are combinations of alleles from each gene: R or r, G or g, w (only w since ww is homozygous), and d (only d since dd is homozygous). For Parent 2 (rrGgWwDd), the possible gametes are: r (only r since rr is homozygous), G or g, W or w, and D or d.
Step 3: Use a Punnett square or probability rules to calculate the genotype combinations for each gene in the progeny. For each gene, calculate the proportion of offspring with the desired phenotype: round (R_), yellow (G_), purple (W_), and tall (D_). For example, R_ means either RR or Rr, which results in round seeds.
Step 4: Multiply the probabilities for each gene to find the proportion of progeny with the desired combination of traits. Since the traits are independently assorted, the probability of each phenotype can be multiplied together to determine the overall proportion of progeny that are round, yellow, purple, and tall.
Step 5: Summarize the results by expressing the proportion of progeny with the desired phenotype (round, yellow, purple, and tall) as a fraction or percentage. Ensure that the calculations account for all possible combinations of alleles and their associated phenotypes.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Genotype and Phenotype

The genotype refers to the genetic makeup of an organism, represented by alleles (e.g., Rr, Gg). The phenotype is the observable traits resulting from the genotype, such as seed shape or flower color. Understanding the relationship between genotype and phenotype is crucial for predicting the traits of offspring in genetic crosses.
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Gamete Genotypes

Punnett Square

A Punnett square is a diagram used to predict the genetic outcomes of a cross between two organisms. It allows for the visualization of how alleles from each parent combine to form the genotypes of the offspring. This tool is essential for calculating the expected proportions of different phenotypes in the progeny.
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Chi Square Analysis

Independent Assortment

Independent assortment is a principle of genetics stating that alleles for different traits segregate independently during gamete formation. This means that the inheritance of one trait does not affect the inheritance of another, allowing for a variety of combinations in the offspring. This concept is key to understanding the expected ratios of phenotypes in the progeny of the given cross.
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Gamete Genetics and Independent Assortment
Related Practice
Textbook Question

A pea plant that has the genotype RrGgwwdd is crossed to a plant that has the rrGgWwDd genotype. The R gene controls round versus wrinkled seed, the G gene controls yellow versus green seed, the W gene controls purple versus white flower, and the D gene controls tall versus short plants. Determine the following;


What are the phenotypes of each plant?

575
views
Textbook Question

A pea plant that has the genotype RrGgwwdd is crossed to a plant that has the rrGgWwDd genotype. The R gene controls round versus wrinkled seed, the G gene controls yellow versus green seed, the W gene controls purple versus white flower, and the D gene controls tall versus short plants. Determine the following;


What proportion of the progeny are expected to have the genotype RrGGwwDd?

431
views
Textbook Question

A pea plant that has the genotype RrGgwwdd is crossed to a plant that has the rrGgWwDd genotype. The R gene controls round versus wrinkled seed, the G gene controls yellow versus green seed, the W gene controls purple versus white flower, and the D gene controls tall versus short plants. Determine the following;


What proportion of the progeny are expected to have the genotype rrggwwdd?

486
views
Textbook Question

Go to the OMIM website (http://www.ncbi.nlm.nih.gov/omim) and locate the Search button at the top of the page. Use the search function to look up, one by one, the following three human hereditary diseases that are relatively common in certain populations: 'Tay–Sachs disease' (select OMIM number 272800 from the search results list); 'cystic fibrosis' (select OMIM number 602421 from the search results list); and 'sickle cell anemia' (select OMIM 603903 from the search results list). For each of these diseases, look through the information and provide the following details:

On which chromosome is the gene for the disease located?

605
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Textbook Question

Go to the OMIM website (http://www.ncbi.nlm.nih.gov/omim) and locate the Search button at the top of the page. Use the search function to look up, one by one, the following three human hereditary diseases that are relatively common in certain populations: 'Tay–Sachs disease' (select OMIM number 272800 from the search results list); 'cystic fibrosis' (select OMIM number 602421 from the search results list); and 'sickle cell anemia' (select OMIM 603903 from the search results list). For each of these diseases, look through the information and provide the following details:

What gene is mutated in the disease?

677
views
Textbook Question

Go to the OMIM website (http://www.ncbi.nlm.nih.gov/omim) and locate the Search button at the top of the page. Use the Search function to look up, one by one, the following three human hereditary diseases that are relatively common in certain populations: 'Tay–Sachs disease' (select OMIM number 272800 from the search results list); 'cystic fibrosis' (select OMIM number 602421 from the search results list); and 'sickle cell anemia' (select OMIM 603903 from the search results list). For each of these diseases, look through the information and provide the following details:

Briefly describe the disease.

438
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