Pedigree Analysis: Master Family History Analysis in Biology

Question 1

In a pedigree chart, an individual with two affected parents and no unaffected siblings is most likely to have which genotype?

Accepted Answer

Homozygous dominant

Answer

Heterozygous

Answer

Homozygous recessive

Answer

Cannot be determined

Question 2

What is the expected phenotypic ratio in the offspring of a homozygous dominant parent and a homozygous recessive parent?

Accepted Answer

1:1

Answer

3:1

Answer

9:3:3:1

Answer

1:2:1

Question 3

Which of the following conditions is an example of a recessive sex-linked disorder?

Accepted Answer

Haemophilia

Answer

Sickle cell anaemia

Answer

Cystic fibrosis

Answer

Down syndrome

Question 4

Which inheritance pattern is characterized by offspring having an equal likelihood of inheriting either allele from each parent?

Accepted Answer

Codominant

Answer

Dominant

Answer

Recessive

Answer

Incomplete dominance

Question 5

In a cross between two heterozygous individuals for a dominant trait, what percentage of offspring are expected to exhibit the recessive phenotype?

Accepted Answer

25%

Answer

0%

Answer

50%

Answer

75%

Question 6

Which of the following is an example of a sex-linked trait?

Accepted Answer

Red-green color blindness

Answer

Eye color

Answer

Height

Answer

Blood type

Question 7

In a pedigree, a male individual with the recessive phenotype has a father with the dominant phenotype. What is the genotype of the father?

Accepted Answer

Heterozygous

Answer

Homozygous dominant

Answer

Homozygous recessive

Answer

Cannot be determined

Question 8

Which of the following represents a dominant allele?

Accepted Answer

Uppercase letter

Answer

Lowercase letter

Answer

Superscript letter

Answer

Symbol

Question 9

Which of the following traits is carried on the X chromosome?

Accepted Answer

Haemophilia

Answer

Eye colour

Answer

Hair colour

Answer

Height

Question 10

In a pedigree, when both males and females are equally affected by a trait, which inheritance pattern is most likely?

Accepted Answer

Autosomal dominant

Answer

Autosomal recessive

Answer

X-linked dominant

Answer

Y-linked

Question 11

What does the presence of a 'skipped' generation in a pedigree usually indicate?

Accepted Answer

A recessive trait

Answer

A dominant trait

Answer

A sex-linked trait

Answer

A mitochondrial trait

Question 12

Which of the following is NOT an advantage of using pedigrees in genetic analysis?

Accepted Answer

Provide information about the molecular basis of genetic disorders

Answer

Help identify patterns of inheritance

Answer

Predict the likelihood of inheriting a genetic disorder

Answer

Determine the carrier status of individuals

Question 13

In a pedigree, if an individual carries both dominant and recessive alleles, they will most likely:

Accepted Answer

Show the dominant phenotype

Answer

Show the recessive phenotype

Answer

Show an intermediate phenotype

Answer

Not exhibit the trait

Question 14

Which trait is most likely to be influenced by genes on the sex chromosomes?

Accepted Answer

Colour blindness

Answer

Brown eyes

Answer

Blue eyes

Answer

Height

Question 15

In a family pedigree, a daughter receives the dominant allele for a trait from her father and the recessive allele from her mother. What is the father's genotype?

Accepted Answer

Heterozygous dominant (Aa)

Answer

Homozygous dominant (AA)

Answer

Homozygous recessive (aa)

Answer

Cannot be determined from the given information

Question 16

A woman with the genotype Aa for a certain trait marries a man with the genotype aa. What is the probability that their first child will exhibit the dominant trait?

Accepted Answer

50%

Answer

0%

Answer

25%

Answer

75%

Question 17

Which symbol in a pedigree indicates an individual who is unaffected and homozygous dominant for a trait?

Accepted Answer

Filled square (■)

Answer

Circle (○)

Answer

Square (□)

Answer

Dot (●)

Question 18

A pedigree analysis reveals that a particular trait is more prevalent in males than females. Which explanation is most likely?

Accepted Answer

The trait is sex-linked.

Answer

The trait is autosomal dominant.

Answer

The trait is autosomal recessive.

Answer

The pedigree is incomplete.

Question 19

In a cross between two heterozygous dominant individuals, what proportion of the offspring will be homozygous recessive?

Accepted Answer

25%

Answer

0%

Answer

50%

Answer

100%

Question 20

Which mode of inheritance results in the expression of a trait in both sexes equally?

Accepted Answer

Autosomal dominant

Answer

Autosomal recessive

Answer

X-linked dominant

Answer

Y-linked

Question 21

Which of the following is a characteristic of a recessive allele?

Accepted Answer

Only expressed in homozygous individuals

Answer

Expressed in homozygous or heterozygous individuals

Answer

Dominant over other alleles

Answer

Present in all individuals

Question 22

Which of the following statements about sex-linked traits is correct?

Accepted Answer

They are more common in males than females

Answer

They are always inherited from the mother

Answer

They are always dominant

Answer

They are only expressed in females

Question 23

Which of the following is a potential limitation of pedigree analysis?

Accepted Answer

It may not provide complete information about genotypes

Answer

It can only be used to study dominant traits

Answer

It requires very large family datasets

Answer

It is not useful for identifying genetic disorders

Question 24

In a pedigree chart, which symbol represents a male who is a carrier for a recessive genetic disorder?

Accepted Answer

A half-shaded square

Answer

An unshaded square

Answer

A fully shaded square

Answer

An unshaded circle

Question 25

In a pedigree chart, which symbol represents a female individual?

Accepted Answer

Circle

Answer

Square

Answer

Triangle

Answer

Diamond

Question 26

For a dominant trait, individuals who have one copy of the dominant allele and one copy of the recessive allele will:

Accepted Answer

Express the dominant phenotype

Answer

Express the recessive phenotype

Answer

Have a 50% chance of expressing the dominant phenotype

Answer

Have a 50% chance of expressing the recessive phenotype

Question 27

Which of the following is a limitation of pedigree analysis?

Accepted Answer

It cannot determine the exact genotype of an individual

Answer

It can only be used to study rare traits

Answer

It is not reliable for tracking inheritance over multiple generations

Answer

It can only be used to study Mendelian traits

Question 28

In a pedigree chart, a shaded symbol indicates:

Accepted Answer

An affected individual

Answer

An unaffected individual

Answer

A carrier of the trait

Answer

A deceased individual

Question 29

Which pattern of inheritance is characterized by a dominant allele masking the effect of a recessive allele?

Accepted Answer

Autosomal dominant

Answer

Autosomal recessive

Answer

X-linked dominant

Answer

X-linked recessive

Question 30

A female who possesses only one copy of a recessive allele is known as:

Accepted Answer

Heterozygous

Answer

Homozygous dominant

Answer

Homozygous recessive

Answer

Hemizygous

Question 31

Which characteristic is NOT associated with sex-linked traits?

Accepted Answer

Autosomal inheritance

Answer

Higher prevalence in males

Answer

Transmission from mother to son

Answer

Different expression in males and females

Question 32

In a pedigree, what does a double line connecting two symbols indicate?

Accepted Answer

Married couple

Answer

Siblings

Answer

Parent-child relationship

Answer

Identical twins

Question 33

Which inheritance pattern is exhibited by a trait that is only transmitted from fathers to sons?

Accepted Answer

Y-linked

Answer

Autosomal dominant

Answer

Autosomal recessive

Answer

X-linked dominant

Question 34

Which pattern of inheritance indicates that the trait is dominant?

Accepted Answer

Every individual with at least one copy of the gene expresses the trait

Answer

Only individuals with two copies of the gene express the trait

Question 35

Which of the following is an example of a sex-linked recessive trait?

Accepted Answer

Haemophilia

Answer

Blue eyes

Answer

Down syndrome

Answer

Cystic fibrosis

Question 36

If a mother is heterozygous for a dominant trait and the father is homozygous recessive, what is the probability of their child expressing the trait?

Accepted Answer

50%

Answer

0%

Answer

25%

Answer

75%

Question 37

What is the main goal of pedigree analysis?

Accepted Answer

To track the inheritance of traits through generations

Answer

To identify genetic mutations

Answer

To predict the genotype of future offspring

Answer

To diagnose genetic disorders

Question 38

In a pedigree, a shaded rectangle indicates an individual who is:

Accepted Answer

Affected by the trait being studied

Answer

A carrier for the trait being studied

Answer

Unaffected by the trait being studied

Answer

Deceased

Question 39

In a pedigree, if both parents are unaffected but have an affected child, the most likely inheritance pattern is:

Accepted Answer

Autosomal recessive

Answer

Autosomal dominant

Answer

X-linked dominant

Answer

X-linked recessive

Question 40

In a pedigree, a dashed line connecting two individuals indicates:

Accepted Answer

Marriage

Answer

Parent-child relationship

Answer

Sibling relationship

Answer

Identical twin relationship

Question 41

In a pedigree, a diagonal line through a symbol indicates an individual who is:

Accepted Answer

Deceased

Answer

Adopted

Answer

Dizygotic (fraternal) twin

Answer

Monozygotic (identical) twin

Question 42

Which of the following symbols represents a male individual affected by a recessive trait?

Accepted Answer

■

Answer

○

Answer

□

Answer

●

Question 43

In a pedigree, an arrow connecting two individuals indicates:

Accepted Answer

Mating between individuals

Answer

Parent-child relationship

Answer

Adoption

Answer

Sibling relationship

Question 44

Which of the following inheritance patterns is characterized by the affected trait appearing in every generation?

Accepted Answer

Autosomal dominant

Answer

Sex-linked recessive

Answer

Autosomal recessive

Answer

Sex-linked dominant

Question 45

Which of the following terms refers to an individual who has two different alleles for a particular gene?

Accepted Answer

Heterozygous

Answer

Carrier

Answer

Homozygous

Answer

Phenotype

Question 46

A genetic counselor is studying a family history of a rare genetic disorder. Which of the following would be most helpful in determining the mode of inheritance?

Accepted Answer

A pedigree

Answer

A karyotype

Answer

A blood test

Answer

A DNA sequence analysis

Question 47

Which of the following symbols represents a female individual who is a carrier of a recessive trait?

Accepted Answer

○/

Answer

○

Answer

●

Answer

●/