Chapter 2.3: Mendelian Inheritance in Humans

Question 1

Define carrier

Answer 1

individual that bears a dominant normal allele that masks the effects of the recessive abnormal one

Question 2

What pattern of inheritance do recessive traits show?

Answer 2

horizontal pattern of inheritance

Question 3

Define consanguineous mating

Answer 3

a mating between relatives

Question 4

Define late-onset genetic trait

Answer 4

trait for which symptoms are not present at birth and manifests themselves later in life

Question 5

What pattern of inheritance do dominant traits show?

Answer 5

vertical pattern of inheritance

Question 6

What does a horizontal pattern of inheritance mean?

Answer 6

The trait 1st appears among several members of one generation and is not seen in earlier generations

Question 7

What is an area of genetics that analyzes differences among individuals?

Answer 7

population genetics

Question 8

Define population genetics

Answer 8

area of genetics that analyzes differences among individuals

Question 9

What is a trait for which symptoms are not present at birth and manifests themselves later in life?

Answer 9

late-onset genetic trait

Question 10

What does a vertical pattern of inheritance mean?

Answer 10

the trait shows up in every generation

Question 11

What is a pedigree?

Answer 11

o A family history, known as a pedigree, is an orderly diagram of a family’s relevant genetic features

Question 12

What are ways to recognize a dominant trait in a pedigree?

Answer 12

• Affected children always have at least one affected parent
• As a result, dominant traits show a vertical pattern of inheritance: the trait shows up in every generation
• 2 affected parents can produce unaffected children, if both are heterozygotes

Question 13

What are ways to recognize a recessive trait in a pedigree?

Answer 13

• Affected individuals can be children of 2 unaffected carriers, particularly as a result of consanguineous matings
• All the children of 2 affected parents should be affected
• Rare recessive traits show a horizontal pattern of inheritance: The trait 1st appears among several members of one generation and is not seen in earlier generations
• Recessive traits may show a vertical pattern of inheritance if the trait is extremely common in the population

Question 14

What is a mating between relatives?

Answer 14

consanguineous mating

Question 15

What is an individual that bears a dominant normal allele that masks the effects of the recessive abnormal one?

Answer 15

carrier