Exam 8: The Inheritance of Multiple Genes

Genes usually have multiple alleles. Alleles that have the same phenotype can be grouped together. Alleles can also be ranked in an allelic series, such as with agouti, which governs coat color in dogs and other animals. Rank the following alleles for the hypothetical gene C, governing hair color, in order of dominance (most dominant first). There are four alleles: C^r, C^y, C^b, and C^w. Individuals homozygous for these alleles have red, yellow, black, and brown hair, respectively. C^r_ individuals have red hair. Heterozygotes carrying C^y do not have yellow hair. In a cross between homozygous C^b and C^w individuals, ¾ of the offspring have brown hair. -C^b

Genes usually have multiple alleles. Alleles that have the same phenotype can be grouped together. Alleles can also be ranked in an allelic series, such as with agouti, which governs coat color in dogs and other animals. Rank the following alleles for the hypothetical gene C, governing hair color, in order of dominance (most dominant first). There are four alleles: C^r, C^y, C^b, and C^w. Individuals homozygous for these alleles have red, yellow, black, and brown hair, respectively. C^r_ individuals have red hair. Heterozygotes carrying C^y do not have yellow hair. In a cross between homozygous C^b and C^w individuals, ¾ of the offspring have brown hair. -C^y

Phenotypes are not always inherited in a predictable Mendelian manner. Which of the following are possible reasons for this? Please select all that apply.

Which of the following statements about the offspring of a cross between two carriers of a lethal recessive gene are true? Please select all that apply.

What is meant by variable expressivity?

Match the phenotypes to their dominance descriptions for the following example. Growth of a heterozygote, Yy, is the same as that of homozygote YY. Homozygote yy does not grow. Yy produces about half as much pigment as YY, and yy does not produce any pigment.

If fewer than 100% of individuals that are homozygous for a mutant allele exhibit the mutant phenotype, the mutant allele is described as having reduced______

When considering the inheritance of multiple independent traits, it is often simpler to multiply the probability of each individual trait to determine the probability of the overall phenotype. Assuming inheritance is independent, in a cross between two tall pea plants with yellow round peas and purple flowers, genotype YyRrTtPp, what is the probability that offspring will be tall and have white flowers and produce yellow wrinkled peas? Your answer should be the value of A in the fraction A/256