PATHOPHYSIOLOGY 8TH EDITION MCCANCE
PRACTICE SOLUTION 2026 QUESTIONS WITH
COMPLETE ANSWERS GRADED A+
◉ Exchange of DNA between chromosomes; robertsonian is one
type, is an example of what abnormality in the Chromosome
structure. Answer: Translocation
◉ What is a locus. Answer: The position for a specific gene on each
paired chromosome
◉ What is meant by homozygous and heterozygous. Answer:
Homozygous: Both alleles at a given locus are identical
Heterozygous: Alleles at a given locus are different from one another
◉ What is the relationship between genotype and phenotype?.
Answer: Genotype: The composition of genes at a given locus
Phenotype: Outward appearance that is influenced by genes and
environment
,◉ What is meant by dominant and recessive allele?. Answer:
Dominant allele: Effects are observable in the heterozygote
Recessive allele: Effects are observable only in the homozygote
◉ What is a carrier?. Answer: An individual that possesses genes for
a disease but does not show phenotypical characteristics of the
disease.
◉ What is the usual pattern of mating that gives rise to offspring
affected by an autosomal dominant trait?. Answer: Autosomal
dominant inheritance means that the phenotypic trait is expressed
whenever the gene is present, whether in the homozygote or the
heterozygote.
Autosomal dominant gene mutations are rarely homozygous, so the
vast majority of mating occurs between a heterozygous affected
parent and a normal parent (both alleles normal).
50% of the offspring from this mating will be affected.
The trait does not skip generations.
, ◉ Genomic imprinting. Answer: The process of gene silencing, in
which genes are predictably silenced depending on which parent
transmits them. People inherit two copies of their genes—one from
their mother and one from their father. Usually both copies of each
gene are active, or "turned on," in cells. In some cases, however, only
one of the two copies is normally turned on. Which copy is active
depends on the parent of origin: some genes are normally active
only when they are inherited from a person's father; others are
active only when inherited from a person's mother. This
phenomenon is known as genomic imprinting.
◉ Autosomal Dominant Disease - No Hx Cause: New genetic
mutation. Answer: If a child is born with an autosomal dominant
disease and there is no family history of that disease, then one of the
parent's germ cells must have acquired a new mutation.
◉ What is incomplete penetrance of a trait. in Autosomal Dominant
Disorders?. Answer: Some individual who inherit an autosomal
dominant gene do not develop the full expression of the disease and
are only mildly affected. This results from incomplete penetrance of
a trait.
◉ Huntington Chorea is an example of. Answer: In Autosomal
Dominant Disorders, Another kind of penetrance is age-dependent
in which the symptoms of an inherited autosomal dominant
disorder do not appear until later in life as is seen with Huntington
chorea.
PRACTICE SOLUTION 2026 QUESTIONS WITH
COMPLETE ANSWERS GRADED A+
◉ Exchange of DNA between chromosomes; robertsonian is one
type, is an example of what abnormality in the Chromosome
structure. Answer: Translocation
◉ What is a locus. Answer: The position for a specific gene on each
paired chromosome
◉ What is meant by homozygous and heterozygous. Answer:
Homozygous: Both alleles at a given locus are identical
Heterozygous: Alleles at a given locus are different from one another
◉ What is the relationship between genotype and phenotype?.
Answer: Genotype: The composition of genes at a given locus
Phenotype: Outward appearance that is influenced by genes and
environment
,◉ What is meant by dominant and recessive allele?. Answer:
Dominant allele: Effects are observable in the heterozygote
Recessive allele: Effects are observable only in the homozygote
◉ What is a carrier?. Answer: An individual that possesses genes for
a disease but does not show phenotypical characteristics of the
disease.
◉ What is the usual pattern of mating that gives rise to offspring
affected by an autosomal dominant trait?. Answer: Autosomal
dominant inheritance means that the phenotypic trait is expressed
whenever the gene is present, whether in the homozygote or the
heterozygote.
Autosomal dominant gene mutations are rarely homozygous, so the
vast majority of mating occurs between a heterozygous affected
parent and a normal parent (both alleles normal).
50% of the offspring from this mating will be affected.
The trait does not skip generations.
, ◉ Genomic imprinting. Answer: The process of gene silencing, in
which genes are predictably silenced depending on which parent
transmits them. People inherit two copies of their genes—one from
their mother and one from their father. Usually both copies of each
gene are active, or "turned on," in cells. In some cases, however, only
one of the two copies is normally turned on. Which copy is active
depends on the parent of origin: some genes are normally active
only when they are inherited from a person's father; others are
active only when inherited from a person's mother. This
phenomenon is known as genomic imprinting.
◉ Autosomal Dominant Disease - No Hx Cause: New genetic
mutation. Answer: If a child is born with an autosomal dominant
disease and there is no family history of that disease, then one of the
parent's germ cells must have acquired a new mutation.
◉ What is incomplete penetrance of a trait. in Autosomal Dominant
Disorders?. Answer: Some individual who inherit an autosomal
dominant gene do not develop the full expression of the disease and
are only mildly affected. This results from incomplete penetrance of
a trait.
◉ Huntington Chorea is an example of. Answer: In Autosomal
Dominant Disorders, Another kind of penetrance is age-dependent
in which the symptoms of an inherited autosomal dominant
disorder do not appear until later in life as is seen with Huntington
chorea.
