The most common CF mutation is AF508; it accounts for approximate 70% of all mutant CFTR alleles worldwide. For a couple of northern European origin, what is their risk for having an affected child if each tests negative for AF508? If one tests positive and the other tests negative for AF508?

Sickle cell anemia is a genetically inherited autosomal recessive trait in which results in a condition that there are not enough healthy red blood cells to carry oxygen throughout the body due to the production of red blood cells that are sickle shaped. The frequency of the sickle cell condition is as high as 10% in Central Africa compared to 0.5% in the United States. Calculate the frequency of the normal and carries of the sickle cell condition.

Why Recessive CF disease alleles either produce no CFTR or produce nonfunctional or less functional versions of the protein?

APOE gene has been found to be a major contributor to sporadic Alzheimer's disease (AD), by acting as an age-of-onset modifier for the common relatively late-onset forms of the disease. Among four alleles causing early onset of AD, the epsilon4 allele (APOE4) disrupts this function. If you generate transgenic monkeys in which the normal allele of APOE gene is knocked out, what phenotype will you expect for those knockout monkeys? A. The APE mRNA expression will be completely suppressed. B. They slow down the development of AD. C. They develop AD early. D. They don't show any AD symptom.

In Huntington’s disease, the wild-type allele, h, is recessive to the disease allele, H. The persistence of an autosomal dominant allele that is fatal in 100% of cases is best explained by which of the following? A) The dominant allele only has moderate negative effects during adolescence and young adulthood. B) The wild-type h allele continues to spontaneously mutate into the dominant H allele. C) The persistence of any given allele in nature is determined almost wholly by chance. D) The disease has no effects until the individual has reached an age far past the normal age for reproduction.

Six single-nucleotide polymorphism (SNP) loci are known to contribute to the development of type 2 diabetes. Diabetes is certain if eight or more of the alleles at these six loci are of the “contributing” variety. An uppercase letter indicates an allele that contributes to diabetes and a lowercase symbol indicates a noncontributing allele. A married couple wants to know the probability of producing a child who is at severe risk of type 2 diabetes. Their genotypes were determined by microarray analysis and are as follows: AaBbccDDEEFf × AaBbCCDdEeFf

Several genes in humans in addition to the ABO gene(I) give rise to recognizable antigens on the surface ofred blood cells. The MN and Rh genes are two examples. The Rh locus can contain either a positive or anegative allele, with positive being dominant to negative. M and N are codominant alleles of the MN gene.The following chart shows several mothers and theirchildren. For each mother-child pair, choose the fatherof the child from among the males in the right column, assuming one child per male.Mother Child Malesa. O M Rh(pos) B MN Rh(neg) O M Rh(neg)b. B MN Rh(neg) O N Rh(neg) A M Rh(pos)c. O M Rh(pos) A M Rh(neg) O MN Rh(pos)d. AB N Rh(neg) B MN Rh(neg) B MN Rh(pos)

Cystic fibrosis (CF) is an autosomal recessive trait. A three-generation pedigree is shown below for a family that carries the mutant allele for cystic fibrosis. Note that carriers are not colored in to allow you to figure out their genotypes.      Normal allele =  F      CF mutant allele =  f        What is the genotype of individual #13? A) ff B) FF C) Ff  D) it is impossible to tell

Give nine examples of lethal alleles in humans, other animals, and plants and a brief molecular explanation (i.e., why are they lethal).

Given that II2 has cystic fibrosis, what is the chance that III8 will be a carrier of the CF allele? Please explain. Please note that II7 is FF.