![GENETIC ANALYSIS: AN INTEG. APP. W/MAS](https://www.bartleby.com/isbn_cover_images/9781323142790/9781323142790_largeCoverImage.gif)
Define and distinguish incomplete penetrance and variable expressivity.
![Check Mark](/static/check-mark.png)
To analyze:
The differences and definitions for the given terms – Incomplete penetrance and Variable expressivity.
Introduction:
The phenotypic variation seen in the population is due the genotypic difference that results in that phenotype. If a particular genotype produces the expected phenotype, it said to be complete penetrance. On the other hand, if a genotype does not produce the expected phenotype, but rather results in a variable phenotype, the reason behind this is gene-environmental interactions between the alleles of other genes in the genome.
Explanation of Solution
Explanation:
Penetrance- If a phenotype is accordant with the genotype, the organism is said to be “Penetrant” for the trait whereas if the phenotype is inconsistent with the genotype, it said to be “Non-penetrant.” When the traits for a genotype result in the estimated phenotype, it is called “Fully penetrant” while if the organism has the effective gene but still fails to show the expected phenotype, it is called an incomplete penetrance. The highly penetrated alleles are studied by clinicians and geneticist. The importance of studying the penetrance benefits in identifying the individuals who are prone to a particular disease.
Expressivity- Expressivity is the extent to which an individual shows a phenotype or a trait or mutation. The variable expressivity refers to the phenotypic expression to a different degree with the same genotype.
a. Incomplete penetrance- If the organism has the effective gene still it fails to show the expected phenotype, it is called incomplete penetrance.
b. Variable expressivity- The degree of phenotypic expression varies in different individual with the same genotype.
Sr No. | Incomplete penetrance | Variable expressivity |
1. | Individual do not express the phenotype; however they have the allele. | Symptoms contrast in intensity in different individuals. |
2. | Example- Polydactyly. | Example- Waardenburg syndrome. |
Thus it is concluded that incomplete penetrance is a condition in which the organism has the effective gene still it fails to show the expected phenotype. Variable expressivity is the degree of phenotypic expression that varies in different individual with the same genotype.
Want to see more full solutions like this?
Chapter 4 Solutions
GENETIC ANALYSIS: AN INTEG. APP. W/MAS
Additional Science Textbook Solutions
Campbell Biology (11th Edition)
Fundamentals of Anatomy & Physiology Plus Mastering A&P with eText - Access Card Package (10th Edition) (New A&P Titles by Ric Martini and Judi Nath)
Human Anatomy & Physiology
Anatomy & Physiology
Campbell Essential Biology with Physiology (6th Edition)
Becker's World of the Cell (9th Edition)
- Variations in Phenotype Expression Define penetrance and expressivity.arrow_forwardDescribe the chromosomal alterations and phenotype of cri du chat syndrome and Prader-Willi syndrome.arrow_forwardA pedigree analysis was performed on the family of a man with schizophrenia. Based on the known concordance statistics, would his MZ twin be at high risk for the disease? Would the twins risk decrease if he were raised in an environment different from that of his schizophrenic brother?arrow_forward
- Explain what nondisjunction is, and give two examples of phenotypes that can result from it.arrow_forwardDescribe how alleles can exhibit incomplete penetrance andvary in their expressivity.arrow_forwardList all the components that contribute to the phenotypic variance and define each component.arrow_forward
- Describe the various polymorphisms in detail. What distinguishes them from one another?arrow_forwardDescribe the following (50 words minimum per concept): chromosomes, genes, alleles and traits and explain how they are related.arrow_forwardA woman homozygous dominant for albinism marries a man who is homozygous recessive for albinism. What are the possible genotypes and phenotypes percentages for their offspring?arrow_forward
- A woman and a man have a red-green colorblind daughter. What can you say about the genotypes of the parents? Be specific and complete, using correct conventional notation.arrow_forwardi) Assuming brown eyes (E) are dominant over blue eyes (e), determine the genotypes of all the following individuals. The blue-eyed son of two brown-eyed parents marries a brown eyed woman whose mother was brown eyed and whose father was blue eyed. Their child is blue eyed.arrow_forwardPlease calculate the Chi-square valuearrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage LearningHuman Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305251052/9781305251052_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305112100/9781305112100_smallCoverImage.gif)