Disruptive Trait The figure above shows disruptive selection. The trait distribution changes from the black line to the green (lighter) line. During disruptive selection as shown above The standard deviation of the trait distribution decreases The standard deviation of the trait distribution increases The mean value of the trait distribution is selected for OThe mean value of the trait distribution in the population becomes smaller O The mean value of the trait distribution in the population becomes larger Frequency

Disruptive Trait The figure above shows disruptive selection. The trait distribution changes from the black line to the green (lighter) line. During disruptive selection as shown above The standard deviation of the trait distribution decreases The standard deviation of the trait distribution increases The mean value of the trait distribution is selected for OThe mean value of the trait distribution in the population becomes smaller O The mean value of the trait distribution in the population becomes larger Frequency

Human Anatomy & Physiology (11th Edition)

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...

See similar textbooks

Similar questions

Two traits with similar phenotypic variance exist in apopulation. One trait has two major genes and sixminor loci that influence the phenotypic value, andthe second trait has 12 minor loci and no major genesaffecting the phenotypic value. Does this informationtell you which trait you should expect to respondmost consistently to selection? Explain why it doesor does not.
. A chicken breeder is working with a population in whichthe mean number of eggs laid per hen in one month is 28and the variance is 5 eggs2. The narrow-sense heritabilityis known to be 0.8. Given this information, can the breeder expect that the population will respond to selectionfor an increase in the number of eggs per hen in the nextgeneration?a. No, applying selection is always risky and a breedernever knows what to expect.b. No, a breeder needs to know the broad-senseheritability to know what to expect.c. Yes, since the narrow-sense heritability is close to1 (0.8), then we would expect selective breeding couldlead to increased egg production in the next generation.d. Yes, since the variance is greater than 0.e. Both c and d are correct.
Small population size causes genetic drift because ofchance sampling of different alleles from one generation to the next. We can predict how much geneticdrift occurs for a given population size using binomialsampling statistics. With a population of size N, wecan estimate that 95% of the time the allele frequency(p) in the next generation will be withinthe confidence interval of p ± 1.96 (√p(1 − p)2N ),where p(1 − p)2Nis an estimate of the statistical variancein allele frequencies from one generation to the nextwith random sampling of 2N alleles each generation. a. What is the confidence interval for p = 0.5 whenN = 100,000?b. What is the confidence interval for p = 0.5 whenN = 10?c. How are the results in parts (a) and (b) related tothe consequences of a population bottleneck?
The following table gives the percentage of twinpairs studied in which both twins expressed the same phenotypefor a trait (concordance). Percentages listed arefor concordance for each trait in monozygotic (MZ) anddizygotic (DZ) twins. Assuming that both twins in eachpair were raised together in the same environment, whatdo you conclude about the relative importance of geneticversus environmental factors for each trait?
A botanist studying water lilies in an isolated pond observedthree leaf shapes in the population: round, arrowhead, and scalloped.Marker analysis of DNA from 125 individuals showed theround-leaf plants to be homozygous for allele r1, while the plantswith arrowhead leaves were homozygous for a different allele atthe same locus, r2. Plants with scalloped leaves showed DNA profileswith both the r1 and r2 alleles. Frequency of the r1 allele wasestimated at 0.81. If the botanist counted 20 plants with scallopedleaves in the pond, what is the inbreeding coefficient F forthis population?
The original source of new alleles, upon which selection operates,is mutation, a random event that occurs without regard to selectionalvalue in the organism. Although many model organismshave been used to study mutational events in populations, someinvestigators have developed abiotic molecular models. Soll et al.(2006. Genetics 175:267–275) examined one such model to studythe relationship between both deleterious and advantageousmutations and population size in a ligase molecule composed ofRNA (a ribozyme). Soll found that the smaller the population ofmolecules, the more likely it was that not only deleterious mutationsbut also advantageous mutations would disappear. Whywould population size influence the survival of both types ofmutations (deleterious and advantageous) in populations?
A large, genetically heterogeneous group of tomato plants was usedas the original breeding stock by two different breeders, namedMary and Hector. Each breeder was given 50 seeds and began aselective breeding strategy, much like that described in Figure24.11. The seeds were planted, and the breeders selected the 10plants with the highest mean tomato weights as the breeding stockfor the next generation. This process was repeated over the courseof 12 growing seasons, and the following data were obtained: A. Explain these results.B. Another tomato breeder, named Martin, got some seeds fromMary’s and Hector’s tomato strains (after 12 generations),grew the plants, and then crossed them to each other. The mean weight of the tomatoes in these hybrids was about 1.7 pounds.For a period of 5 years, Martin subjected these hybrids to thesame selective breeding strategy that Mary and Hector had followed,and he obtained the following results: Explain Martin’s data. Why was Martin able to obtain…
Figure 19-9 shows the trait distributions before and aftera cycle of artificial selection. Does the variance of thetrait appear to have changed as a result of selection?Explain.
The F2 distribution of three human traits are shown in the graphs below. Which of the three traits is most likely the result of the largest number of genes? Trait 1 ratio: 1441 Classes Trait 2 ratie 11s20151 Classes Trait 3 F ratio 12420281 Classes OCengage Leaning It is not possible to tell how many genes are involved in a trait form the F2 distribution O All three traits are equally likely the result of multiple genes Trait 1 Trait 3 Trait 2 % of individuals % of individuals % of individuals
Many genetic disorders, such as cystic fibrosis and sickle-cell disease are due to mutations in a recessive allele. You have sampled an isolated population in which you know that the percentage of the homozygous recessive genotype (aa) is 36%. Using that 36%, calculate: 1g. the frequency of the recessive phenotype if "A" is completely dominant over "a” (round to the nearest hundredth)
Inbreeding in a population causes a deviation fromHardy–Weinberg expectations such that there aremore homozygotes than expected. For a locus with arare deleterious allele at a frequency of 0.04, whatwould be the frequency of homozygotes for the deleterious allele in populations with inbreeding coefficientsof F = 0.0 and F = 0.125?
Which type of selection (directional, disruptive, stabilizing) changes the overall average phenotype in a population? How does it do this? What does "additive” mean? Why aren't dominant and epistatic variances considered to be additive?