Exam 2) NSG 533 Exam 2: Questions & Answers
What is genetics? - ANSWER:Study of inherited traits and variations; examination of a particular/small
group of gene(s); focused/individual picture
What is genomics? - ANSWER:Total genetic composition of organism/species; analysis of entire species
genome; broad view
Gene - ANSWER:Basic unit of heredity that codes for specific protein leading to a characteristic or
function
Allele - ANSWER:One version of a gene at a given location along a chromosome
Mutant alleles - ANSWER:Can be:
-disease causing mutations
-polymorphism (alterations with normal gene function)
-variant of unknown significance
Phenotype - ANSWER:Observable physical / biochemical characteristics of gene expression; clinical
presentation
Variability is a good reason because - ANSWER:-maintains robust population
-homogeneity weakens d/t inability to adapt
-may leave it more vulnerable to others
Penetrance - ANSWER:Proportion of individuals with mutation who exhibit clinical symptoms
Huntington's = 100% penetrance
Consanguinity - ANSWER:Genetic relatedness between individuals descending from at least one
common ancestor
Increases autosomal recessive diseases
Anticipation - ANSWER:Tendency for disorders in successive generations to present at an earlier age
and/or with more severe manifestations
Mosaicism - ANSWER:Occurrence of two or more cell lines with different genetic or chromosomal
constitutions
Gene Deletion - ANSWER:Absence of a DNA segment; likely most critical d/t loss of genetic material
, Gene Duplication - ANSWER:Presence of an extra DNA segment resulting in redundant portions, an
entire gene, or a series
-caused by unequal crossing-over during gene replication
Gene Inversion - ANSWER:Chromosomal rearrangement; segment has inverted and reinserted at the
same breakage site
-balance: usually no abnormalities
-unbalanced: almost always abnormal
Gene Translocation - ANSWER:Chromosomal alteration; whole/segment chromosome becomes attached
or interchanged with another whole/segment chromosome
Gene Mutation - ANSWER:Any alteration in a gene from its natural state; disease causing or benign
Autosomal dominant - ANSWER:Phenotype expressed in those who only have one copy of gene
mutation
Autosomal recessive - ANSWER:Phenotype expressed in those who have two copies of gene mutation
X-linked dominant - ANSWER:Dominant trait caused by mutation in X chromosome
Expressed in heterozygous females and hemizygous males; more severe in males
Heterozygote advantage - ANSWER:Possession of single copy does not result in gene expression and
provides benefit, but increases chance to pass down gene
-sickle cell
-cystic fibrosis
-tay sach's
Key components to accurate family history (genogram) - ANSWER:-dead, no disease
-dead, disease diagnosis year
-disease and diagnosis year
-no disease (alive)
BRCA 1 and BRCA 2 - ANSWER:Linked to breast and ovarian cancers
APC - ANSWER:Familial adenomatous polyposis = FAP
Rare autosomal dominant colon cancer
What is genetics? - ANSWER:Study of inherited traits and variations; examination of a particular/small
group of gene(s); focused/individual picture
What is genomics? - ANSWER:Total genetic composition of organism/species; analysis of entire species
genome; broad view
Gene - ANSWER:Basic unit of heredity that codes for specific protein leading to a characteristic or
function
Allele - ANSWER:One version of a gene at a given location along a chromosome
Mutant alleles - ANSWER:Can be:
-disease causing mutations
-polymorphism (alterations with normal gene function)
-variant of unknown significance
Phenotype - ANSWER:Observable physical / biochemical characteristics of gene expression; clinical
presentation
Variability is a good reason because - ANSWER:-maintains robust population
-homogeneity weakens d/t inability to adapt
-may leave it more vulnerable to others
Penetrance - ANSWER:Proportion of individuals with mutation who exhibit clinical symptoms
Huntington's = 100% penetrance
Consanguinity - ANSWER:Genetic relatedness between individuals descending from at least one
common ancestor
Increases autosomal recessive diseases
Anticipation - ANSWER:Tendency for disorders in successive generations to present at an earlier age
and/or with more severe manifestations
Mosaicism - ANSWER:Occurrence of two or more cell lines with different genetic or chromosomal
constitutions
Gene Deletion - ANSWER:Absence of a DNA segment; likely most critical d/t loss of genetic material
, Gene Duplication - ANSWER:Presence of an extra DNA segment resulting in redundant portions, an
entire gene, or a series
-caused by unequal crossing-over during gene replication
Gene Inversion - ANSWER:Chromosomal rearrangement; segment has inverted and reinserted at the
same breakage site
-balance: usually no abnormalities
-unbalanced: almost always abnormal
Gene Translocation - ANSWER:Chromosomal alteration; whole/segment chromosome becomes attached
or interchanged with another whole/segment chromosome
Gene Mutation - ANSWER:Any alteration in a gene from its natural state; disease causing or benign
Autosomal dominant - ANSWER:Phenotype expressed in those who only have one copy of gene
mutation
Autosomal recessive - ANSWER:Phenotype expressed in those who have two copies of gene mutation
X-linked dominant - ANSWER:Dominant trait caused by mutation in X chromosome
Expressed in heterozygous females and hemizygous males; more severe in males
Heterozygote advantage - ANSWER:Possession of single copy does not result in gene expression and
provides benefit, but increases chance to pass down gene
-sickle cell
-cystic fibrosis
-tay sach's
Key components to accurate family history (genogram) - ANSWER:-dead, no disease
-dead, disease diagnosis year
-disease and diagnosis year
-no disease (alive)
BRCA 1 and BRCA 2 - ANSWER:Linked to breast and ovarian cancers
APC - ANSWER:Familial adenomatous polyposis = FAP
Rare autosomal dominant colon cancer
