Choose an organism that is a product of artificial selection. Give a brief description of your organism and its desired traits. What wild ancestor did it come from? Was it produced with selective breeding or genetic engineering (i.e. genetically modified)? What are the benefits of artificial selection in this case? Are there potential negative consequences?

Why are only inherited variations important in the evolutionary process? Explain your answer.

Why dont genetic markers on the Y chromosome undergo recombination? Why is this lack of recombination a necessity for these markers to be used in tracing migrations?

Discuss the significance of the HardyWeinberg principle as it relates to evolution and list the five conditions required for genetic equilibrium.

Figure 10.7 Why was Dolly a Finn-Dorset and not a Scottish Blackface sheep?

The reason spontaneous mutations do not have an immediate effect on allele frequencies in a large population is that: a. mutations are random events, and mutations may be eitherbeneficial or harmful. b. mutations usually occur in males and have little effect oneggs. c. many mutations exert their effects after an organism hasstopped reproducing. d. mutations are so rare that mutated alleles are greatlyoutnumbered by nonmutated alleles. e. most mutations do not change the amino acid sequence of aprotein.

Match the modes of natural selection with their best description. ____ stabilizing a. eliminates extreme forms of a trait ____ directional b. eliminates midrange forms of a trait ____ disruptive c. shifts phenotypes in one direction

The Joneses were referred to a clinical geneticist because their 6-month-old daughter was failing to grow adequately and was having recurrent infections. The geneticist took a detailed family history (which was uninformative) and a medical history of their daughter. He discovered that their daughter had a history of a constant cough and wheeze that was becoming progressively worse, had difficulty gaining weight (failure to thrive), and had an extensive history of yeast infection (thrush) in her mouth. The geneticist did a simple blood test to check their daughters white blood count and determined that she had severe combined immunodeficiency (SCID). The geneticist explained that SCID is an immune deficiency that causes a marked susceptibility to infections. The defining characteristic is usually a severe defect in both the T- and B-lymphocyte systems. This results in one or more infections within the first few months of life that are serious and may even be life-threatening. Based on the family history, it was possible that their daughter had inherited a mutant allele from each of them and therefore was homozygous for a gene that causes SCID. If so, each time the Joneses had a child, there would be a 25% chance that the child would have SCID. Prenatal testing is available to determine whether the developing fetus has SCID. If the Joneses want to be certain that their next child will not have SCID, what types of reproductive options do you think they have?

What is probability, and how is it applied in genetic analysis?

Pedigree analysis is a fundamental tool for investigating whether or not a trait is following a Mendelian pattern of inheritance. It can also be used to help identify individuals within a family who may be at risk for the trait. Adam and Sarah, a young couple of Eastern European Jewish ancestry, went to a genetic counselor because they were planning a family and wanted to know what their chances were for having a child with a genetic condition. The genetic counselor took a detailed family history from both of them and discovered several traits in their respective families. Sarahs maternal family history is suggestive of an autosomal dominant pattern of cancer predisposition to breast and ovarian cancer because of the young ages at which her mother and grandmother were diagnosed with their cancers. If a mutant allele that predisposed to breast and ovarian cancer was inherited in Sarahs family, she, her sister, and any of her own future children could be at risk for inheriting this mutation. The counselor told her that genetic testing is available that may help determine if this mutant allele is present in her family members. Adams paternal family history has a very strong pattern of early onset heart disease. An autosomal dominant condition known as familial hypercholesterolemia may be responsible for the large number of deaths from heart disease. As with hereditary breast and ovarian cancer, genetic testing is available to see if Adam carries the mutant allele. Testing will give the couple more information about the chances that their children could inherit this mutation. Adam had a first cousin who died from Tay-Sachs disease (TSD), a fatal autosomal recessive condition most commonly found in people of Eastern European Jewish descent. Because TSD is a recessively inherited disorder, both of his cousins parents must have been heterozygous carriers of the mutant allele. If that is the case, Adams father could be a carrier as well. If Adams father carries the mutant TSD allele, it is possible that Adam inherited this mutation. Because Sarah is also of Eastern European Jewish ancestry, she could also be a carrier of the gene, even though no one in her family has been affected with TSD. If Adam and Sarah are both carriers, each of their children would have a 25% chance of being afflicted with TSD. A simple blood test performed on both Sarah and Adam could determine whether they are carriers of this mutation. If Sarah carries the mutant cancer allele and Adam carries the mutant heart disease allele, what is the chance that they would have a child who is free of both diseases? Are these good odds?