Exam 3: Mendelian Genetics

Tightly curled or wooly hair is caused by a dominant gene in humans.If a heterozygous curly-haired person marries a person with straight hair,what percentage of their offspring would be expected to have straight hair?

The Chi-square test involves a statistical comparison between measured (observed)and predicted (expected)values.One generally determines degrees of freedom as ________.

Which types of phenotypic ratios are likely to occur in crosses when dealing with two gene pairs for which all the genotypic combinations are of equal viability?

A 9:3:3:1 phenotypic ratio is expected from a dihybrid testcross.

Assume that you have a garden and some pea plants have solid leaves and others have striped leaves.You conduct a series of crosses [(a)through (e)] and obtain the results given in the table.Define gene symbols and give the possible genotypes of the parents of each cross. Cross Progeny solid striped (a) solid \times striped 55 60 (b) solid \times solid 36 0 (c) striped \times striped 0 65 (d) solid \times solid 92 30 (e) solid \times striped 44 0

In a Chi-square analysis,what condition causes one to reject (fail to accept)the null hypothesis?

Assuming a typical monohybrid cross in which one allele is completely dominant to the other,what ratio is expected if the F₁s are crossed?

Assume that a cross is made between a heterozygous tall pea plant and a homozygous short pea plant.Fifty offspring are produced in the following frequency: 30 = tall 20 = short a) What frequency of tall and short plants is expected? b) To test the goodness of fit between the observed and expected values,provide the needed statement of the null hypothesis. c) Compute a Chi-square value associated with the appropriate test of significance. d) How many degrees of freedom are associated with this test of significance?

In peas,gray seed color is dominant to white.For the purposes of this question,assume that Mendel crossed plants with gray seeds with each other and the following progeny were produced: 320 gray and 80 white. a) What is the most probable genotype of each parent? a) What genotypic and phenotypic ratios are expected in the progeny of such a cross?

Mendel's postulate of independent assortment is supported by a 1:1:1:1 testcross ratio.

What are two typical testcross ratios?

Which types of phenotypic ratios are likely to occur in crosses when dealing with a single gene pair for which all the genotypic combinations are of equal viability?

Under what conditions does one expect a 9:3:3:1 ratio?

In what ways is sample size related to statistical testing?

Assume that a Chi-square test provided a probability value of 0.02.Should the null hypothesis be accepted?

In studies of human genetics,usually a single individual brings the condition to the attention of a scientist or physician.When pedigrees are developed to illustrate transmission of the trait,what term does one use to refer to this individual?

Mendel's discoveries were well received and understood by his contemporaries.

Assume that a black guinea pig crossed with an albino guinea pig produced 5 black offspring.When the albino was crossed with a second black guinea pig,4 black and 3 albino offspring were produced.What genetic explanation would apply to these data?

In a Chi-square test,as the value of the χ² increases,the likelihood of rejecting the null hypothesis ________.[one word]

Which of the following groups of scientists were influential around the year 1900 in setting the stage for our present understanding of transmission genetics?