Genetics: Analysis and Principles
6th Edition
ISBN: 9781259616020
Author: Robert J. Brooker Professor Dr.
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 28, Problem 21CONQ
When artificial selection is practiced over many generations, it is common for the trait to reach a plateau in which further selection has little effect on the outcome of the trait. This phenomenon is illustrated in Figure 28.11. Explain why it occurs.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
What are two reasons why a selection limit is reached in which artificial selection no longer has an effect?
Is each of the following examples due to directional, disruptive, balancing, or stabilizing selection?
A. Polymorphisms in snail color and banding pattern as described.
B. Thick fur among mammals exposed to cold climates
C. Birth weight in humans
D. Sturdy stems and leaves among plants exposed to windy climates
How does the concept of artificial selection is applied in the creation and domestication of chihuahuas out of wolves? Explain in an explicit way.
Chapter 28 Solutions
Genetics: Analysis and Principles
Ch. 28.1 - 1. Which of the following is an example of a...Ch. 28.1 - 2. Saying that a quantitative trait follows a...Ch. 28.2 - The variance is a. a measure of the variation...Ch. 28.2 - 2. Which of the following statistics is used to...Ch. 28.3 - 1. For many quantitative traits, genotypes and...Ch. 28.4 - A QTL is a __________ where one or more genes...Ch. 28.4 - 2. To map QTLs, strains are crossed that differ...Ch. 28.5 - 1. In a population of squirrels in North Carolina,...Ch. 28.5 - Prob. 2COMQCh. 28.5 - 3. One way to estimate narrow-sense heritability...
Ch. 28.6 - 1. For selective breeding to be successful, the...Ch. 28.6 - Prob. 2COMQCh. 28 - Give several examples of quantitative traits.How...Ch. 28 - 2. At the molecular level, explain why...Ch. 28 - 3. What is a normal distribution? Discuss this...Ch. 28 - 4. Explain the difference between a continuous...Ch. 28 - What is a frequency distribution? Explain how such...Ch. 28 - 6. The variance for weight in a particular herd of...Ch. 28 - Two different varieties of potato plants produce...Ch. 28 - 8. If , would you conclude that a positive...Ch. 28 - Prob. 9CONQCh. 28 - When a correlation coefficient is statistically...Ch. 28 - 11. What is polygenic inheritance? Discuss the...Ch. 28 - What is a quantitative trait locus (QTL)? Does a...Ch. 28 - 13. Let’s suppose that weight in a species of...Ch. 28 - Prob. 14CONQCh. 28 - 15. From an agricultural point of view, discuss...Ch. 28 - Many beautiful varieties of roses have been...Ch. 28 - 17. In your own words, explain the meaning of the...Ch. 28 - 18. What is the difference between broad-sense...Ch. 28 - The heritability for egg weight in a group of...Ch. 28 - In a fairly large population of people living in a...Ch. 28 - When artificial selection is practiced over many...Ch. 28 - 22. Discuss whether a natural population of wolves...Ch. 28 - 23. With regard to heterosis, is each of...Ch. 28 - Here are data for height and weight among 10 male...Ch. 28 - 2. The abdomen length (in millimeters) was...Ch. 28 - 3. You conduct an RFLP analysis of head weight in...Ch. 28 - 5. Let’s suppose that two strains of pigs differ...Ch. 28 - Prob. 6EQCh. 28 - In a wild strain of tomato plants, the phenotypic...Ch. 28 - The average thorax length in aDrosophilapopulation...Ch. 28 - 9. In a strain of mice, the average 6-week body...Ch. 28 - Prob. 10EQCh. 28 - 11. A danger in computing heritability values from...Ch. 28 - For each of the following relationships,...Ch. 28 - An animal breeder had a herd of sheep with a mean...Ch. 28 - The trait of blood pressure in humans has a...Ch. 28 - Discuss why heritability is an important...Ch. 28 - From a biological viewpoint, speculate as to why...Ch. 28 - 3. What is heterosis? Discuss whether it is caused...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- In a large population, dairy cows were selected for high milk production. What do you expect to happen with the genes affecting milk production? Do you expect to see a higher or lower variability of alleles after several years of selection?arrow_forwardIs it likely that the selection coefficient (s) is similar in value for the three populations shown? Is it important to know if the amount of genetic variation for the trait under selection is approximately equal in all three populations in the graph? Why or why not?arrow_forwardWhy are some types of traits are highly heritable and other types of traits are not as highly heritable? Some traits are morphology, life history, behavior, and physiology.arrow_forward
- What evolutionary factors can cause allele frequencies to change and possibly lead to a genetic polymorphism? Discuss the relative importance of each type of process.arrow_forwardThere are two incomplete-dominant alleles for petal color in a population of flowers. 36% of the flowers have red petals, 16% of the organisms have white petals, and 48% of the flowers have pink petals. What percentage of alleles in this population code for red petals (R)? how can i calculate it?arrow_forwardWhich of the following is the MOST important characteristic of a trait for it to undergo descent with modification? A. It must be heritable. B. It must exhibit variation. C. It must exhibit phenotypic plasticity. D. Variation in the trait must be accompanied by variation in fitness.arrow_forward
- Harmful alleles persist in some populations, explain how this is possible with natural selection occurring?arrow_forwardWhat is artificial selection? Provide an example.arrow_forwardHalf of the worlds population eats rice at least twice a day. Much of this rice is grown in flooded conditions, and different strains of rice are tolerant (survive) or intolerant (die) under these conditions. Rice breeders used genetic crosses to test whether tolerance to flooding is a dominant trait. Researchers used three true-breeding flood-tolerant strains, FR143, BKNFR, and Kurk, and two true-breeding flood- intolerant strains, IR42 and NB, in the crosses. Results were obtained from three sets of crosses and are reported in the Table below: Results of cross of F1 to tolerant parent: F1 plants were crossed with the tolerant parent of the cross. Number of Plants Progeny Analyzed from Intolerant Tolerant Cross Alive Dead Total 1. F2 results of cross: IR42 FR13A 187 77 264 IR42 BKNFR 192 73 265 NB Kurk 142 52 195 2. Results of cross of F1 to intolerant parent: (F1 of IR42 FR13A) IR42 14 17 31 (F1 of IR42 BKNFR) IR42 15 10 25 (F1 of NB Kurk) NB 21 35 56 3. Results of cross of F1 to tolerant parent: (F1 of IR42 FR13A) FR13A 31 0 31 (F1 of IR42 BKNFR) BKNFR 28 0 28 (F1 of NB Kurk) Kurk 40 0 40 Do the data support the hypothesis that the tolerance trait is dominant? Justify your conclusion by explaining the results from each of the three sets of crosses in terms of genotypes and phenotypic ratios. Source: T. Setter et al. 1997. Physiology and genetics of submergence tolerance in rice. Annals of Botany 79:6777.arrow_forward
- Imagine that genetic technology advances to the point where the genetic profile of an individual can be easily obtained, and that we have a full understanding of how genes interact to influence our health. Based on this genetic information alone, how reliably do you think we would be able to predict a person's chance of getting a specific disease? Where do you think this type of genetic profiling would lead with respect to selection of offspring or genetic superiority?arrow_forwardWe have learned that the response to selection is equal to the selection differential times the narrow-sense heritability, and that the narrowsense heritability includes only the additive genetic variance. Why aren’t the dominance genetic variance and the gene interaction variance included? Why don’t they contribute to the genetic variation that is acted on by selection?arrow_forwardDuring the millennia in which selective breeding was practiced, why did breeders fail to uncover the principle that traits are governed by discrete units of inheritance (that is, by genes)?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Biology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage Learning
Biology: The Dynamic Science (MindTap Course List)
Biology
ISBN:9781305389892
Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan
Publisher:Cengage Learning
Genetic Variation and Mutation | 9-1 GCSE Science Biology | OCR, AQA, Edexcel; Author: SnapRevise;https://www.youtube.com/watch?v=bLP8udGGfHU;License: Standard YouTube License, CC-BY