Concept explainers
FROM DATA TO DECISION
Critical Thinking: Did Mandal’s results from plant hybridization experiments contradict his theory?
Gregor Mendel conducted original experiments to study the genetic train of pea plaits. In 1865 he wrote “Experiments in Plant Hybridization.” which was published in Proceedings of the Natural History Society Mendel presented a theory that when there are two inheritable, one of them will be dominant and the other will be recessive. Each parent contributes one gene to an offspring and, depending on the combination of genes, that offspring could inherit the dominant trait or the recessive trait. Mendel conducted an experiment using pea plants. The pods of pea plants can be green or yellow. When one pea carrying a dominant green gene and a recessive yellow gene is crossed with another pea carrying the same green/yd low genes, the offspring can inherit any one of these four combinations of genes: (1) green/green; (2) green/yellow; (3) yellow /green: (4) yellow /yellow. Because green is dominant and yellow is recessive, the offspring pod will be green if either of the two inherited genes is green. The offspring can have a yellow pod only if it inherits the yellow gene from each of the two parents. Given these conditions, we expect that 3/4 of the offspring peas should have green pods; that is. P(green pod) = 3/4. When Mendel conducted his famous hybridization experiments using parent pea plants with the green/yellow combination of genes, he obtained 580 offspring. According to Mendel’s theory. 3/4 of the offspring should have green pods, bat the actual number of plants with green pods was 428. So the proportion of offspring with green pods to the total number of offspring b 428/580 = 0.738. Mendel expected a proportion of 3/4 or 0.75, but his actual mull is a proportion off 0.738.
- a. Assuming that P(green pod) = 3/4, find the probability that among 580 offspring, the number of peas with green pods b exactly 428.
- b. Assuming that P(green pod) = 3/4. find the probability that among 580 offspring, the number of peas with green pods b 428 or fewer.
- c. Which of the two preceding probabilities should be used for determining whether 428 is a significantly low number of peas with green pods?
- d. Use probabilities to determine whether 428 peas with green pods is a significantly low number. (Hint: See “Identifying Significant Results with Probabilities” in Section 5-1.)
Trending nowThis is a popular solution!
Chapter 5 Solutions
Elementary Statistics
- As mentioned in Experimental Question E11, red eyes is the wildtype phenotype. Several different genes (with each gene existing intwo or more alleles) are known to affect eye color. One allelecauses purple eyes, and a different allele causes sepia eyes. Both ofthese alleles are recessive to red eye color. When flies with purpleeyes were crossed to flies with sepia eyes, all of the F1 offspringhad red eyes. When the F1 offspring were allowed to mate witheach other, the following data were obtained:146 purple eyes151 sepia eyes50 purplish sepia eyes444 red eyesExplain this pattern of inheritance. Conduct a chi sqarrow_forward1. According to a certain Mendelian genetic model, self-pollination of pink-flowered plants should produce progeny that are red, pink, and white in the ratio 1:2:1. A geneticist self-pollinated pink-flowered snapdragon plants and produced 234 progeny with 54 red, 122 pink and 58 white flowered plants. To test if these numbers indeed follow the model ratio, what should be an appropriate null hypothesis? A. P(Red) = 54/234, P(Pink) = 122/234, P(White) = 58/234. B. P(Red) = 54%, P(Pink) = 122%, P(White) = 58%. C. P(Red) = 1, P(Pink) = 2, P(White) = 1. D. P(Red) = 0.25, P(Pink) = 0.5, P(White) = 0.25. 2. What would be the degree of freedom for an appropriate test? A. 3 B. 2 C. 1 D. 0 3. If we fail to reject the null hypothesis at 0.05 significance level, what do you conclude? A. The self-pollinated plants of the geneticist do not follow the ratio 1:2:1 and this validates the model. B. The self-pollinated plants of the…arrow_forward3.Luijckx et al (2012) discovered that resistance to the bacterial parasite Pasteuria ramose is genetically variable in the common freshwater crustacean, Daphnia magna. To investigate the genetic basis of this variation, they crossed a completely resistant lineage to a completely susceptible lineage. All the F1 offspring were resistant. These offspring, when mature, were then crossed to each other to produce an F2 generation. If resistance is the result of only a single gene with two forms (alleles) then resistant and susceptible F offspring should occur in a 3:1 ratio. Of 71 F2’s tested, 57 were resistant and 14 were susceptible. a.With these data, calculate the range of most plausible-values for the proportion of resistant offspring. Does the plausible range include the proportion predicted if resistance is determined by a single gene? b.Give two other values for proportion that are also consistent with the data. c.Test the genetic hypothesis. Are the results compatible with the…arrow_forward
- Example 2.9 Suppose that a particular trait of a person (such as eye color or left handedness) is classified on the basis of one pair of genes and suppose that d represents a dominant gene and r a recessive gene. Thus a person with dd genes is pure dominance, one with rr is pure recessive, and one with rd is hybrid. The pure dominance and the hybrid are alike in appearance. Chil- dren receive one gene from each parent. If, with respect to a particular trait, two hybrid parents have a total of four children, what is the probability that exactly three of the four children have the outward appearance of the dominant gene?arrow_forwardA team of researchers is testing the effectiveness of a new HPV vaccine. They randomly divide the subjects into two groups. Group 1 receives the new HPV vaccine, and Group 2 receives the existing HPV vaccine. Neither the patients or the doctors examining them knew which group they were in. Which is the treatment group? O Group 1 O Group 2 O Neither group Which is the control group (if there is one)? O Group 1 O Group 2 O No control group Is this study blind, double blind, or neither? ete O Blind O Double-blind O Neither Novt Ouertionarrow_forwardA goodness-of-fit test is designed to deal with multiple categories at once. See Section 6.7 for more details. A crop researcher investigated the phenotypes that resulted from crossing two different types of tomato plants. There are 4 possible resulting phenotypes (numbered 1, 2, 3, 4 in the data table below). Mendel's laws of genetic inheritance ('the model') suggest that the proportions should be 9/16, 3/16, 3/16 and 1/16 for phenotypes 1, 2, 3, 4 respectively. The classification of a sample of 1611 observations is given below together with the proportions suggested by Mendel's laws of inheritance (the model). According to the model, what is the expected number of observations in this sample that would be Phenotype 4? Expected number =arrow_forward
- Question 1 > Dogs are inbred for such desirable characteristics as blue eye color; but an unfortunate by-product of such inbreeding can be the emergence of characteristics such as deafness. A 1992 study of Dalmatians (by Strain and others, as reported in The Dalmatians Dilemma) found the following: (i) 31% of all Dalmatians have blue eyes. (ii) 38% of all Dalmatians are deaf. (iii) 42% of blue-eyed Dalmatians are deaf. What is the probability that a randomly chosen Dalmatian is blue-eyed and deaf? .31 * .38 = .1178 O.31 * .42 = .1302 .38 * .42 = .1596 .31 / .38 = .8158 0.31 / .42 = .7381 0.38 / .42 = .9048 Submit Questionarrow_forwardA social psychologist studying mass communication randomly assigned 77 volunteers to one of two experimental groups. Fifty-seven were instructed to get their news for a month only from television, and 20 were instructed to get their news for a month only from the Internet. After the month was up, all participants were tested on their knowledge of several political issues. The researcher simply predicted that there is some kind of difference. These were the results of the study. TV group: Mty = 22, S, = 2; Internet group: M, = 26.2, s = 3. The pooled variance, rounded to four decimal places, is 2.2533. Complete parts (a) and (b) below. (a) Figure the estimated effect size for this study. Let the TV group be sample 1 and let the Internet group be sample 2. The estimated effect size for this study isarrow_forwardIt has been observed that some persons who suffer colitis, again suffer colitis within one year of the first episode. This is due, in part, to damage from the first episode. The performance of a new drug designed to prevent a second episode is to be tested for its effectiveness in preventing a second episode. In order to do this two groups of people suffering a first episode are selected. There are 55 people in the first group and this group will be administered the new drug. There are 45 people in the second group and this group will be administered a placebo. After one year, 11% of the first group has a second episode and 9% of the second group has a second episode. Conduct a hypothesis test to determine, at the significance level 0.1, whether there is reason to believe that the true percentage of those in the first group who suffer a second episode is different from the true percentage of those in the second group who suffer a second episode? Select the [Alternative Hypothesis,…arrow_forward
- Mr. Andrews, a grape merchant, inquires about a certain wine that he tastes at a party. The host tells him that from a total of ten bottles of that wine, six came from the north vineyard and four came from the south vineyard. From this information, the merchant concludes that he should visit the north vineyard for a sample of the grapes. Later, he discovers that the wine in question came from a bottle labeled Classic Reserve, and 30 of 100 barrels of north vineyard wine were bottled with that label, while 130 of 200 barrels of south vineyard wine were bottled with that label. Given this new information, what is the probability that the wine came from the north vineyard? (Hint: For this exercise, use Bayes's theorem.)arrow_forwardA study is testing the effectiveness of a new allergy medication. Sixty people who reported they experience allergies were randomly assigned to one of two groups: one with the new medication, and another with a placebo. After two weeks, the subjects were surveyed by technicians to determine their level of allergic symptoms. Which of the following would benefit this experiment the most? A. This experiment should be double blind. Neither the subject nor the technician should know which group is receiving the new medication and which is receiving the placebo. This method would control for the placebo effect and prevent any effect on the response. B. This experiment should be single blind. The subjects do not know which treatment they are receiving to control for the placebo effect, but the technicians need to know which group received which treatment. C. This experiment should be single blind. The subjects know which treatment they are receiving but the technicians do not know which…arrow_forwardThere are few diseases that have only one causal agent and most diseases are caused by a constellation of factors. A. True B. Falsearrow_forward
- MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
- Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman