Pedigrees Practice Problems

If a couple has two children, one of whom is affected by an autosomal recessive disorder, even though neither parent is affected, what can we infer about the couple's genotypes?

If the female is the carrier, about half the sons are affected. If the female is homozygous, 50% of the daughters and 100% of the sons can be affected. Which of the following types of traits does it determine?

A pedigree chart depicting each family member can serve as a representation of a family tree. They may be a carrier of the disease or have a genetic disorder. Standard symbols are used to differentiate between families in the pedigree analysis. In a pedigree chart, a fully shaded square represents:

A man (II-6) with MELAS syndrome wants to marry a woman (II-7) who is not affected with this syndrome. They (II-6 and II-7) visit a genetic counsellor because the syndrome has impacted all of the children of one of his (II-6) married sisters, and the woman (II-7) is concerned that if they marry, their children may be affected as well. An intern working under the genetic counselor whom they visited made four observations after analysing the pedigree given below. Identify which observation of the intern is not correct.

The following pedigree shows the inheritance of an unknown disease "Z" in a family. Examine the pedigree carefully and choose which of the following best explains the inheritance of the disease "Z" in the individuals of the III generation.

For parents who are carriers of certain genetic disorders and don't want to pass on that genetic disorder to their children, what is the importance of knowing the gender of an unborn child? 

One of the most common autosomal dominant disorders is neurofibromatosis type 1. It is a condition characterized by changes in skin coloring (pigmentation) and the growth of tumors along nerves in the skin, brain, and other parts of the body. If a woman with neurofibromatosis type 1 has an unaffected partner, which of the following statements about their children is true?

A female with normal vision has a colorblind son who also has hemophilia. The father of the female did not have hemophilia or colorblindness. The recessive alleles that cause colorblindness and hemophilia are designated by X^b and X^h, respectively, while the normal dominant alleles for the same are designated by X^B and X^H, respectively. Based on this information, determine the genotype of the female.

Huntington's disease is caused by a mutation in a single gene. This is a genetic disorder that affects the brain and if an individual has one copy of the mutated gene, they will have the disease. The mutated gene is passed on from parent to child. What is the probability of each of their children developing the condition, if one parent has the mutated gene?

People who have the sickle cell trait have the genotype HbAS, which is a combination of the dominant allele HbA and the recessive allele HbS. As a result, their red blood cells have a sickle shape because both alleles are expressed in the phenotype. For this observation, what is the name of the genetic phenomenon?

Which of the following statements is false about pedigree analysis?

In which of the following conditions is genetic counseling required or recommended?

What is the probability of an offspring possessing the recessive trait (t), if two individuals with genotype TT are crossed?

What is the inheritance pattern of the ability to bend the thumb back beyond vertical in humans?

The pedigree shown below illustrates the inheritance of a(n) _________ trait in a family.

Which of the following best describes the below-mentioned pedigree? 

What is the purpose of a pedigree chart?

What is a pedigree chart?

What does a horizontal line labeled "X" in the following pedigree chart represent?

The pedigree shown below illustrates how an autosomal recessive disease is passed down via a family.

Which of the following statements best describes the genetic condition of the parents depicted in the pedigree? 

Precancerous cells are abnormal cells that have the potential to become cancerous. They are not yet cancerous, but they have the potential to develop into cancer if left untreated. Precancerous cells can be detected through which of the following tests?

What is the term used to describe a pattern of inheritance where a trait is passed from one generation to the next through unaffected carriers?

If a couple has a grandchild who is born with the autosomal recessive condition, what is the probability that their grandchild's sibling will also have the condition?

A couple has one child with galactosemia and one child without the condition. What is the probability that their next child will have galactosemia?

If upon constructing the pedigree you found out that males of every generation  have the genetic condition while the females are unaffected, the genetic condition is most likely:

Cystic fibrosis is an example of an autosomal recessive genetic disorder. If an affected male (rr) marries an unaffected female (RR), how will it affect their offspring?

A man has a brother suffering from cystic fibrosis, which is an autosomal recessive disorder. What is the probability that the man is a carrier if neither of his parents have cystic fibrosis?

What is the probability of a son being colorblind if his father is colorblind and his mother has normal vision? [Note: There is no family history of colorblindness on the mother's side]

There is a 100% chance that a female will be a carrier for colorblindness when:

Tay-Sachs disease is an autosomal recessive disorder characterized by nerve cell destruction in the brain and spinal cord. A couple's child has been diagnosed with the disorder. What is the probability that their next child will not be affected by the disorder?

Tay-Sachs disease is an autosomal recessive disorder characterized by nerve cell destruction in the brain and spinal cord. A couple's child has been diagnosed with the disorder. What is the probability that their next child will also have the disorder?

In a clinical report, an individual is found to have an obese body habitus and manifestations of metabolic syndrome, which is characterized by diabetes, insulin resistance, hypertension, and hypertriglyceridemia. What is the physician's diagnosis of the disease based on the symptoms?

Which of the following conditions generally occur more frequently in males than in females?

Which of the following is true about X-linked dominant conditions?

Which of the following statements about Y-linked disorders is true?

If the mother is affected by an X-linked dominant disorder (heterozygous), how will it affect their offspring?

If the male parent is affected by a genetic condition that is X-linked dominant, how will it affect their offspring?

Muscular dystrophy is an X-linked recessive condition. If the father is affected by this genetic condition, how will it affect their offspring?

If the affected parents pass a genetic condition to their children regardless of their gender and it is present in every generation, this trait is considered:

If unaffected parents have affected offspring for a certain autosomal condition, it may imply that:

Leigh syndrome is an inherited neurodegenerative condition that can become apparent in infancy. The inheritance of this condition depends on:

Leigh syndrome can be inherited in various ways, it can be inherited when the mutated gene occurs on the X-chromosome. This condition occurs more frequently in males than in females. What type of inheritance pattern is represented in this case based on the epidemiological data presented?

Leigh syndrome can be inherited in various ways, it can be inherited when the mutated genes in mtDNA, such as MT-ATP6, are passed on to the offspring. Provided that condition can affect both male and female offspring, what type of inheritance pattern is represented in this case?

Leigh syndrome can be inherited in various ways, it can be inherited when both copies of the gene in the cell bear the mutations. This can affect the offspring (both male and female) despite having parents who do not show signs and symptoms of the condition. What type of inheritance pattern is represented in this case?

Which of the following gives the pattern of inheritance for conditions caused by mitochondrial DNA mutations?

What is the inheritance pattern of a trait in a pedigree if you see affected offspring of both sexes from unaffected parents?

Identify which of the following pedigrees correctly demonstrates the inheritance of two linked genes on X-chromosomes, the Xg blood group and inherited recessive episodic muscular weakness (EMWX), when a male with Xg⁺ marries a female who is heterozygous for both Xg and EMWX. The genotype of each individual's "Xg blood group" is presented below. (Note: Xg⁺ is linked with the dominant allele of EMWX).

In the following pedigree, identify what percent of the offspring of the II generation will be carriers of the trait.

Which of the following traits is determined by genes found on autosomes and expressed only in one sex?

In which of the following conditions does a carrier female pass the disorder on to her male child?

Examine the pedigree and determine the disorder under investigation.

In the following pedigree, first identify the inheritance of the autosomal trait being studied and then determine the genotypes of III-3 and IV-2. (Assume allele A to be dominant over allele a for the trait being studied in the pedigree).

In the following pedigree, first identify the inheritance of the autosomal trait being studied and then determine the genotypes of II-2 and III-2. (Assume allele A to be dominant over allele a for the trait being studied in the pedigree).

Examine the provided pedigree and decide which assertion(s) about it is/are false.

In court, a healthy couple claims that their child was replaced in the hospital since the one they are raising now has cystic fibrosis. As a student of genetics, why do you think that their claim is potentially wrong?

In the following pedigree, identify the mode of inheritance.

In the following pedigree, identify the mode of inheritance.

In the following pedigree, identify the mode of inheritance.

Examine the pedigree carefully to determine the mode of transmission for a genetic disease.

In the following pedigree, identify the mode of inheritance of a particular trait X.

Which of the following diseases does NOT have an autosomal recessive inheritance pattern?

Determine which of the following pedigrees exhibits autosomal recessive inheritance for a particular trait.

Sickle cell anemia is an autosomal recessive disorder. A female who is a carrier of the sickle cell trait gives birth to one unaffected child and one child with sickle cell disease. Determine the genotype and trait of their father. (Hb^A is the normal hemoglobin allele and Hb^S is the sickle cell hemoglobin allele)

In humans, cystic fibrosis is an autosomal recessive disease. A female suffering from cystic fibrosis give birth to six normal children. Determine the possible genotype of the father. (Assume that F is the normal allele and f is the cystic fibrosis allele)

In humans, cystic fibrosis is an autosomal recessive disease. Determine the genotype of the couple who has two healthy children and one with cystic fibrosis. (Assume that F is the normal allele and f is the cystic fibrosis allele)

Which of the following is represented by the shaded square in a pedigree?

A ______ trait can be masked by the ______ trait if the organism is heterozygous.

In ______ inheritance, male and female offspring are affected equally. ______ inheritance, on the other hand, affects more males than females.