Concept explainers
a.
To determine: The reason behind the father not developing retinoblastoma.
Introduction: Cancer is defined as the condition in which the cells start showing abnormal and uncontrolled growth. The main cause of this condition is due to the mutation in cells. These mutations affect the contact inhibition amongst cells. Retinoblastoma is cancer of eyes in which the retinoblast cells grow uncontrollably.
b.
To determine: The chance that the couple will have another child carrying the mutant allele.
Introduction: The hereditary form of cancer is responsible for bilateral retinoblastoma. Bilateral retinoblastoma is caused due to a mutation in the RB1 gene. This type of cancer occurs due to a mutation in the tumor-suppressing gene and the homozygous condition is required for cancer to occur
c.
To determine: Whether there a benefit to knowing that the son in the given case may develop retinoblastoma.
Introduction: The hereditary form of cancer is responsible for bilateral retinoblastoma. Bilateral retinoblastoma is caused due to a mutation in both the RB1 genes in a person. This type of cancer occurs due to a mutation in the tumor-suppressing gene and the homozygous condition is required for cancer to occur
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Human Heredity: Principles and Issues (MindTap Course List)
- Hemophilia A is caused by a recessive X-linked allele that encodes a defective form of a clotting protein. If a affected father and a mother who is known to not be a carrier have children, what percentage of female offspring will have hemophilia?arrow_forwardUse the pedigree to answer the questions that follow. Make sure you put your answer in the correct blank. A) AB В 1 5 II A A AB B A AB A 3 5 6 7 8 II A A B 2 3 5 6 a) State the possible blood type(s) of individual I-4 b) State the possible blood type(s) of individual I-6 c) State the possible genotype(s) of individual Il-5 d) State the possible genotype(s) of individual II-6 e) Determine the percentage chance that couple Il-4 and Il-5 have another child that has type O blood 2.arrow_forwardA woman is a carrier for hemophilia as well as red-green colorblindness. She has one son that has hemophilia, then one son that is colorblind. Several years later, she has a daughter that has symptoms consistent with hemophilia as well as an attenuated color blindness. How would this come about? (Draw a diagram…) Explain you answer step by step.arrow_forward
- Rh factor is a protein that can be found on the surface of red blood cells. If your phenotype is Rh+ you have this protein on your red blood cells. If your phenotype is Rh-, then you do not have this protein on your red blood cells. Rh factor follows simple Mendelian genetics, meaning if you are Rh positive you can have the genotype Rh+Rh+ or Rh+Rh-. If Ruby's genotype is IBiRh-Rh-, and Sam's genotype is IAIARh+Rh-, what is the probability that their baby will be type AB+?arrow_forwardA) A woman with type O blood is expecting a child. Her husband is type A and her husband's parents both had type AB blood. What will be their child’s blood type? 2. A)A woman with type O blood is expecting a child. Her husband is type A and her husband's parents both had type AB blood. What will be their child’s blood type? B) A couple has one child with type AB blood. If one parent is heterozygous for blood type A and the other parent is homozygous for their blood type, what are the chances of their future children having: Type A blood? Type B blood? Type AB blood? O blood?arrow_forwardHemophilia is an X-linked recessive phenotype. Suppose a man who expresses the hemophilia phenotype has children with a woman who has the normal phenotype (and does not have a family history of hemophilia). If the couple have a son, what are the chances that he will have hemophilia? A) 50% B) 25% C) 0% D) 100%arrow_forward
- Consider a woman whose brother has hemophilia A but whose parents are healthy. What is the chance that she has inherited the hemophilia allele? What is the chance that the woman will conceive a son with hemophilia?arrow_forwardIn man, muscular dystrophy is a condition in which the muscles waste away during early life and may result in a shorter life expectancy. It is due to a sex-linked, recessive gene. A certain couple has five children – three boys (ages 1yr, 3yrs, and 10yrs old) and two girls (ages 5yrs and 7yrs old). The oldest boy shows the symptoms of this disease. You are their family physician and they come to you for advice. What would you tell them about the chances of their other children developing the disease?arrow_forwardCystic Fibrosis (CF) is an autosomal recessive condition. Therefore, heterozygous (Cc) carriers do not display symptoms. Two parents who are carriers plan to start a family and you are a genetic counselor helping to advise them about their chances of having children affected by CF. a) Suppose the couple has 4 children, each one year apart. What is the probability that all 4 children will inherit CF? b) What is the probability that any 3 of their 4 children will not inherit CF, but 1 will be affected? c) What is the probability that their first child will not inherit CF, but the younger 3 children will inherit CF?arrow_forward
- In humans, the Rh factor genetic information is inherited from our parents, but it is inherited independently of the ABO blood type alleles. In humans, Rh+ individuals have the Rh antigen on their red blood cells, while Rh- individuals do not. There are two different alleles for the Rh factor known as Rh+ and rh. Assume that a dominant gene Rh produces the Rh+ phenotype, and that the recessive rh allele produces the Rh- phenotype. In a population that is in Hardy-Weinberg equilibrium, if 160 out of 200 individuals are Rh+, calculate the frequencies of both alleles.arrow_forwardSeveral genes in humans in addition to the ABO gene () give rise to recognizable antigens on the surface of the red blood cells. The Rh marker is determined by positive (R) and negative alleles () of gene R, where R is completely dominant to r. The presence of M and N surface proteins are controlled by two codominant alleles of gene L (LM and LM. For each mother-child pair, choose the father of the child from among the males in the right column. (Assume that all mothers and fathers are HH; there is no involvement of the Bombay phenotype.) Paternal genotypes maybe used once, more than once, or not at all. Each mother-child pair matches with one or more than one paternal genotype. Maternal phenotype: Child phenotype: Paternal genotype: Reset A, M, Rh(neg) O, M, Rh(pos) B, N, Rh(neg) O, N, Rh(pos) O, M, Rh(neg) A, MN, Rh(pos) A, N, Rh(pos) AB, MN, Rh(pos) B, N, Rh(pos) A, MN, Rh(neg) Genotypes of possible fathers AiLMLN rr BiLMLN RR ii LNLN rr ii LMLM rr AALMLN RRarrow_forwardWhat unusual phenomenon is at work in each of the following disorders?arrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning