Exam 9: Patterns of Inheritance

Please read the following scenario to answer the following question. The parents of a child with unusual disease symptoms take the child to a doctor for help. The doctor suspects that the condition might have a genetic basis. She recommends that the child be taken to a specialty clinic where physicians and staff members are trained to diagnose genetic diseases and counsel parents. Ultimately, the child is diagnosed with a rare recessively inherited disease. The parents are tested for the gene, and both are found to be heterozygous. The parents want to have another child but are afraid this child will also be affected. -What would genetic counselors say is the probability that the second child will have the disease?

What is the key to the recognition of codominance?

Red-green color blindness is inherited as a sex-linked recessive trait.The gene is found on the X chromosome.Can a man with normal color vision father a daughter who is red-green color-blind?

Mendel crossed purebred purple-flowered plants with purebred white-flowered plants,and all of the resulting offspring produced purple flowers.The offspring are all ________,and the allele for purple flowers is ________.

What is the basis of Mendel's laws?

An individual with the blood group genotype Lᴹᴸᴺ has the phenotype MN.What is the relationship between the Lᴹ and Lᴺ alleles?

To determine the phenotype of an individual who expresses a dominant trait,you would cross that individual with an individual who ________.

Hypophosphatemia (vitamin D-resistant rickets)is inherited as a sex-linked dominant trait.The relevant gene is found on the X chromosome.What is the expected outcome of a cross between a homozygous recessive woman and a man with hypophosphatemia?

Please read the following scenario to answer the following questions. Widow's peak, a pointed hairline on the forehead, is a genetic trait caused by a dominant allele. It can be traced back through a family's history using pedigree analysis. The pedigree shown here is of three generations of a family. Notice that some individuals (shown in gray) have a widow's peak (W = dominant allele and w = recessive allele). -This pedigree supports the fact that widow's peak is due to a dominant allele,because if it were due to a recessive allele and both parents show the recessive phenotype,then ________.

According to Mendel's law of segregation,________.

What is key to recognition of a trait whose expression is determined by the effects of two or more genes (polygenic inheritance)?

Attached earlobes are recessive to free earlobes.What is the probability of having a child with attached earlobes when an individual with attached earlobes mates with an individual heterozygous for free earlobes?

Please refer to the following art to answer the following questions. -In the accompanying art,you see a table with the actual number of offspring that resulted from a dihybrid cross.The numbers do not show the 9:3:3:1 ratio predicted.One phenotype occurred more than predicted; another occurred less.The reason could be because ________.

Please refer to the following art to answer the following questions. -Recombinant offspring were produced by the mating shown in the accompanying art.What is the recombination frequency of purple round and red long offspring?

Many human traits,such as our performance on intelligence tests or our susceptibility to heart disease,are ________.

An individual with (naturally)curly hair and an individual with (naturally)straight hair mate; all of their offspring have (naturally)wavy hair.What is the relationship between the alleles for hair texture?

Which of the following techniques is used to collect fetal cells during pregnancy for genetic testing?

Linked genes are usually ________.

Round seeds (R)are dominant to wrinkled seeds (r),and yellow seeds (Y)are dominant to green seeds (y).What is the expected phenotypic ratio of a cross between an RrYy and an rryy individual?

Marfan syndrome is the result of inheriting a single allele.Individuals with Marfan syndrome are tall and long-limbed,and have both cardiovascular and eye defects.Of what type of inheritance is the phenotype of Marfan syndrome an example?