Tay-Sachs disease is a recessive genetic disease. Individuals with this disease rarely survive past the age of four. In the general population, approximately 1 person in 300 carries the allele for this disease. However, in some populations, including the Irish Americans, the Ashkenazi Jews, and the Cajuns from Louisiana, the proportion of Tay-Sachs carriers is much higher (1 in 27 to 1 in 50) than in other populations. Such high frequency of an otherwise rare allele is expected when    Question 24 options:   populations experienced disruptive selection   populations were founded by a small number of settlers   the allele is advantageous at the heterozygous state    populations have higher than average mutation rates   populations experienced stabilizing selection

The ABO blood group in humans is controlled by a single locus with three different alleles.  Homozygosity for IA produces type A blood.  Homozygosity for IB produces type B blood. Homozygosity for IO produces type O blood. Type AB blood is produced by the genotype IA/IB.  IO is recessive to IA and IB; thus, IA/IO gives type A blood and IB/IO gives type B blood. In the United States, the allele frequencies for the ABO alleles are given below. The Rh factor in blood typing also has multiple alleles, but the alleles can be classified into two types, positive and negative. Rh+ is dominant over Rh−. The allele frequencies of these alleles are also indicated below. The MN blood antigen trait is controlled by two codominant alleles at a single locus. Type M individuals are homozygous for the M allele, type MN individuals are heterozygous, and type N individuals are homozygous for the N allele (codominant).  In the United States, the allele frequencies for this blood group are also indicated…

A mutation in an of the recessive hemoglobin gene on chromosome 11 causes sickle-cell disease, but also confers malaria resistance. The allele frequency in African Americans is 14%.  1. What percent of the population have two copies of the gene and are therefore immune to malaria? 2. What percent of the population are less susceptible to malaria but do not have sickle-cell anemia since they are heterozygous?

Choose one answer.

Some individuals in a canine population is susceptible to disease X, which strikes the adults. The susceptibility is later found to be determined by a single locus, with the R allele dominant over the r allele, such that the rr individuals are susceptible to the disease and the others immune. A population genetic survey showed that 1% of the newborns carry the rr genotype. Also, an independent estimation showed that mutation rate converting R to r is 5 × 10-3 per generation. You suspected that the r allele frequency is maintained by mutation- selection balance (MSB). If your hypothesis of MSB is true, then what is the survival rate for the rr adults? (Note: the equilibrium allele frequency ĝ is calculated as ĝ where %3D u is the mutation rate and s is the selection coefficient.) 5% 50% 95% 99% None of the above

Which of the following best explains how individuals who inherit phenylketonuria alleles can avoid the symptoms of this disease (mental impairment, foul smelling urine)?

Individuals who find the taste of cilantro to be pleasent have a domiant allele for this taste sensation. Individuals who do not like this flavor are recessive. for this particular taste sensation. A parent who does not like Cilantro has a child with someone who is homozygous dominant for liking the flavor of Cilantro. What are the chances that teh child will not like the Cilantro?    a) 25% b) 50% c) 0% d)100%

Vulcans have pointed ears (determined by allele P), absent adrenals (determined by A), and a right-sided heart(determined by R). All these alleles are dominant to normal Earth alleles: rounded ears (p), present adrenals (a),and a left-sided heart (r). The three loci are autosomaland linked as shown in this linkage map:10 m.u. 25 m.u.P A RMr. Spock, first officer of the starship Enterprise, has aVulcan father and an Earthling mother. If Mr. Spock marries an Earth woman and there is no (genetic) interference, what proportion of their children will havea. Vulcan phenotypes for all three characters?b. Earth phenotypes for all three characters?c. Vulcan ears and heart but Earth adrenals?d. Vulcan ears but Earth heart and adrenals?

The complete absence of one or more teeth (tooth agenesis) is a common trait in humans-indeed, more than 20% of humans lack one or more of their third molars. However, more severe absence of teeth, defined as missing six or more teeth, is less common and frequently an inherited condition. L. Lammi and colleagues examined tooth agenesis in the Finnish family shown in the pedigree below (L. Lammi, American Journal of Human Genetics 74:1043-1050. 2004). Which of the following modes of inheritance best fits the pattern observed in the pedigree? Note that the phenotypes in generation 1 are not known. I3D 1 2 3. 4 7 8 II 2. 6. 8. IV 2. a. Y-linked b. X-linked dominant C. X-linked recessive d. Autosomal recessive e. Autosomal dominant FEB 17 MacBook Air ... 3.

Phenylthiocarbamide (PTC) is an organic compound that either tastes extremely bitter or is tasteless, depending on the genotype of the taster. The tasting allele (T) is dominant over the non-tasting allele (t).  Normal skin pigmentation (N) is dominant over albinism (n).  (It is important to note that this example of PTC tasting cannot be explained with simple genetics, but for the purpose of this question, assume that it can.)  A normally-pigmented woman who cannot taste PTC has an albino father.   The woman married an albino man who can taste PTC and whose mother cannot taste PTC.  For the married couple,  1.  correctly identify their genotypes,  2.  complete a digital Punnett square showing the expected offspring of the couple, and  3.  identify the genotypic and phenotypic ratios of their offspring