An autosomal dominant (AD) trait can be ruled out if what is observed in a pedigree with complete penetrance?
Explanation
The defining rule of dominant inheritance (with full penetrance) is that the trait cannot appear in an individual unless it was also present in one of their parents. An affected individual with two unaffected parents violates this rule.
Other questions
In the context of twin studies, what does the term 'concordance' refer to?
If a trait is entirely determined by genetics, what concordance would be expected in monozygotic twins?
What does a monozygotic twin concordance rate of less than 100 percent for a specific trait indicate?
What is the standard symbol used to represent a male in a pedigree chart?
In a pedigree, what does the term 'proband' or 'propositus' signify?
What is the single most defining characteristic of Y-linked inheritance in a pedigree?
What is the key pattern of mitochondrial inheritance seen in pedigrees?
Which observation in a pedigree would allow you to definitively rule out X-linked dominant (XD) inheritance?
In a pedigree for a rare autosomal recessive (AR) trait, what is a common characteristic feature?
What is the probability that an unaffected individual is a heterozygous carrier for an autosomal recessive trait if their parents are both heterozygous carriers?
Which of the following scenarios can definitively rule out autosomal recessive (AR) inheritance?
What is the most likely mode of inheritance if a trait is rare, appears to skip generations, and is significantly more common in males than females?
How does consanguineous mating affect the likelihood of observing a rare autosomal recessive disorder in a pedigree?
In the provided text, what is a primary limitation of pedigree analysis?
Based on the twin study data for colon cancer (monozygotic concordance 4.7 percent, dizygotic concordance 2.6 percent), what can be concluded about its cause?
What is the purpose of an adoption study in genetics?
In a pedigree analysis of a rare trait, why is it usually assumed that unrelated individuals marrying into the family are not carriers of the trait's allele?
Which of the following modes of inheritance can be conclusively ruled out if a trait is transmitted from a father to his son?
An X-linked recessive (XR) trait can be ruled out if which of the following is observed in a pedigree?
Why are traits caused by genes on the Y chromosome considered rare?
In the analysis of the pedigree in Figure 12, what is the assigned genotype for individual I-4 and why?
What is the probability that individual III-1 in the pedigree from Figure 12 has the genotype Aa?
According to the final calculation in the provided text for the pedigree in Figure 12, what is the overall probability that a child of III-1 and III-2 will be affected with the autosomal recessive trait?
In a pedigree, how is an individual affected by the trait being tracked typically indicated?
What complication in 'real-life' pedigrees can make a dominant trait appear to skip a generation?
According to the twin study data for eye color provided in Table 1, what is the monozygotic and dizygotic concordance respectively?
What did the twin study on Scarlet Fever, with a monozygotic concordance of 88 percent and dizygotic concordance of 92 percent, conclude about the cause of the trait?
How did the text describe the inheritance pattern of Celiac disease?
In the historical context of pedigree analysis, why was the ABO blood group often used for linkage studies?
If a pedigree for a rare trait shows affected individuals in every generation, what is the most likely mode of inheritance?
What does a horizontal line connecting a square and a circle in a pedigree represent?
In the step-by-step probability calculation, why is it assumed that individuals II-3 and II-4 have the genotype AA?
What is the genotype of individual II-5 in the pedigree used for the probability calculation (Figure 12)?
If a trait has a monozygotic concordance of 72 percent and a dizygotic concordance of 74 percent, what is the most likely cause?
If a trait has a monozygotic concordance of 12 percent and a dizygotic concordance of 3 percent, what is the most likely cause?
How many modes of inheritance are discussed in the 'Inferring the Mode of Inheritance' section?
What is the primary reason that it can be difficult to rule out Autosomal Recessive (AR) inheritance even if a trait appears in every generation?
Which of the following describes the key difference in interpreting twin studies versus adoption studies?
How many affected children did the 1975 study on Celiac disease find out of the 36 children born to a parent with the disease?
What does it mean if a trait is described as 'variably expressive'?
In a pedigree showing an X-linked recessive trait, why can an affected daughter not have an unaffected father?
If you observe a pedigree where affected individuals appear in every generation and roughly equal numbers of males and females are affected, but you also see father-to-son transmission, what mode of inheritance can you not rule out?
What is the maximum number of alleles for a single gene that a diploid individual can have?
When comparing possible vs. most likely modes of inheritance, a great discrepancy between the number of affected males and females points toward which type of inheritance?
In the probability calculation shown in Figure 12, what is the probability that individual II-2 is a carrier (Aa)?
What does a diamond symbol containing a number '3' inside represent on a pedigree chart, according to the provided symbol keys?
The chapter discusses how pedigree analysis and twin studies were used to find the causes of Celiac disease. What did these tools help determine?
According to the text, which of these is NOT one of the six modes of inheritance examined using pedigrees?
If two individuals with an autosomal dominant trait have an unaffected child, what can be inferred about the parents' genotypes?