correct answers 2026\2027 A+ Grade
What is genetics?
- correct answer Study of inherited traits and variations; examination of a particular/small group of
gene(s); focused/individual picture
What is genomics?
- correct answer Total genetic composition of organism/species; analysis of entire species genome;
broad view
Gene
- correct answer Basic unit of heredity that codes for specific protein leading to a characteristic or
function
Allele
- correct answer One version of a gene at a given location along a chromosome
Mutant alleles
- correct answer Can be:
-disease causing mutations
-polymorphism (alterations with normal gene function)
-variant of unknown significance
Phenotype
- correct answer Observable physical / biochemical characteristics of gene expression; clinical
presentation
Variability is a good reason because
- correct answer -maintains robust population
,-homogeneity weakens d/t inability to adapt
-may leave it more vulnerable to others
Penetrance
- correct answer Proportion of individuals with mutation who exhibit clinical symptoms
Huntington's = 100% penetrance
Consanguinity
- correct answer Genetic relatedness between individuals descending from at least one common
ancestor
Increases autosomal recessive diseases
Anticipation
- correct answer Tendency for disorders in successive generations to present at an earlier age and/or
with more severe manifestations
Mosaicism
- correct answer Occurrence of two or more cell lines with different genetic or chromosomal
constitutions
Gene Deletion
- correct answer Absence of a DNA segment; likely most critical d/t loss of genetic material
Gene Duplication
- correct 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
- correct answer Chromosomal rearrangement; segment has inverted and reinserted at the same
breakage site
, -balance: usually no abnormalities
-unbalanced: almost always abnormal
Gene Translocation
- correct answer Chromosomal alteration; whole/segment chromosome becomes attached or
interchanged with another whole/segment chromosome
Gene Mutation
- correct answer Any alteration in a gene from its natural state; disease causing or benign
Autosomal dominant
- correct answer Phenotype expressed in those who only have one copy of gene mutation
Autosomal recessive
- correct answer Phenotype expressed in those who have two copies of gene mutation
X-linked dominant
- correct answer Dominant trait caused by mutation in X chromosome
Expressed in heterozygous females and hemizygous males; more severe in males
Heterozygote advantage
- correct 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)
- correct answer -dead, no disease
-dead, disease diagnosis year