12 Figure 14.7 Testing two hypotheses for segregation in a dihybrid cross
13 Figure 14.8 Segregation of alleles and fertilization as chance events
14 Problem #1In garden peas, tallness is dominant and dwarfness is recessive. A heterozygous tall plant is crossed with a dwarf plant. If 40 offspring are produced, how many will be tall?
15 Problem #2In humans, brown eyes are dominant over blue eyes. A brown-eyed man and a blue-eyed woman have two blue-eyed children. What are the chances that their next child will have blue eyes?
16 Problem #3Cystic Fibrosis is inherited as a simple autosomal recessive. Suppose a woman who carries the trait marries a normal man who does not carry it. What percent of their children would be expected to have the disease?
17 Problem #4Classical Albinism is a single-gene disorder caused by the lack of an enzyme necessary for the synthesis of melanin pigments. Enzyme production requires the presence of one normal allele. What progeny and what proportions are expected from a normally pigmented woman who has an albino husband and an albino father?
18 Problem 5If two individuals with the genotype A/a B/b C/c D/d mate, what is the probabilty of getting an individual with the genotype A/A B/b c/c D/d?
19 Problem #6In watermelons, the genes for green color and for short shape are dominant over alleles for striped color and long shape. A plant that is heterozygous for green color and homozygous for short shape is crossed with a plant that is homozygous for striped color and heterosygous for short shape. What proportion of their offspring will be striped and short?
21 Figure 14.9 Incomplete dominance in snapdragon color
22 Figure 14.9x Incomplete dominance in carnations
23 Problem #7In snap dragons, flower color and leaf color are both controlled by partial dominance. Pink flowers and light green leaves are the intermediate conditions. Supposed you crossed two plants, both of which had pink flowers and light green leaves. If there were 16 offspring, how many would you expect to have both pink flowers and light green leaves?
27 Problem 7A woman takes Mr. X to court for child support, but Mr. X swears he is not the father. The woman is blood type A and the baby is blood type A. Which blood type must Mr. X have to prove that he is not the father?
28 Interactions Between Genes PleiotropyEpistasisCollaborationComplementationModifier GenesMultiple Gene Inheritance
34 Problem 8If the dominant allele K is necessary for hearing, and the dominant allele M of another gene results in deafness no matter what other genes are present, what percentage of the offspring produced by the cross between k/k M/m and K/k m/m will be deaf?
67 Figure 15.4 Evidence for linked genes in Drosophila
68 Figure 15.5a Recombination due to crossing over
69 Figure 15.5b Recombination due to crossing over
70 Figure 15.6 Using recombination frequencies to construct a genetic map
71 Figure 15.7 A partial genetic map of a Drosophila chromosome
72 Linkage ProblemIn rabbits, a dominant gene produces spotted body color. Another dominant gene produces short hair and its recessive allele long hair. Rabbits heterozygous for both characteristics were mated with homozygous recessive rabbits. The results of this cross were as follows: 170 with spotted and short; 30 with solid and short hair; 26 with spotted and long; 174 with solid and long. What is the map distance between these genese?