A female carrier of hemophilia mates with a man with hemophilia and has offspring. If the couple has four children, what is the probability that they will have at least three with hemophilia?

In a human, what is the best explanation for being XX and phenotypically male?

The inbreeding coefficient can be defined as the:

A Drosophila geneticist made a cross between females homozygous for three X-linked recessive mutations (y, yellow body; ec, echinus eye shape; w, white eye color) and wild-type males. She then mated the F1 females to triple mutant males and obtained the results shown. Which of the three genes is located in the middle of the other two?  

Which of the following is a/are possible offspring in a mating between grasshoppers?

A randomly pollinated strain of maize produces ears that are 24 cm long on average. In a population of maize produces from first cousin matings, the average ear length is reduced to 23 cm. Predict the average ear length in a population of “full-sibling” matings. Answer will fall into one of the ranges below.

Flower color in a certain plant is determined by two independently assorting genes, B and D. The dominant B allele allows a pigment precursor to be converted into a blue pigment. Without this conversion, the plant is white. The dominant allele D causes the blue pigment to degrade and the resulting phenotype is white, whereas the recessive allele d has no effect. A true-breeding white (bbDD) and a true-breeding blue parental strain were mated. If the F1s were then crossed, what portion of the F2s would you expect to be white?

A medical technician is analyzing a blood sample in a clinical lab. In determining the blood type the technician determines that the red blood cells have both A antigens present on the cell surface and B antigens present on the surface. In this case, the red blood cells are exhibiting a genetic characteristic known as:

Chickens that carry both the alleles for rose comb (R-pp) and pea comb (rrP-) have walnut combs (R-P-), whereas chickens that lack both of these alleles (that is, they are genotypically rr pp) have single combs. From the information about interactions between these two genes given in the chapter, determine the proportion of the offspring that will have the Walnut phenotype from the following crosses: (RrPp) x (rrPp)

In the Chi-Square test a critical value is: