Exam (Ch14) Flashcards
Genotype
the genetic makeup of an organism; particular combination of alleles present in an individual
Polymorphism
any genetic difference among individuals that is present in multiple individuals in a population
Alleles
Different DNA sequences within a gene/different forms of a gene
Phenotype
the presentation of alleles
Genetic Risk Factor
any mutation that increases the risk of disease in an individual
Example of beneficial mutation
Delta 32 (removes 32 base pairs in the coding sequence of the CCR5 gene); Since CCR5 is an HIV receptor, cells lacking CCR5 are more difficult to invade, therefore, progression of AIDS is rarely observed
Mutations are…
spontaneous & random
the rate of mutation per nucleotide per replication is greater in
somatic cells than in germ cells because DNA repair mechanisms are more efficient in germ cells
Germ-Line Mutations
A mutation that occurs in eggs and sperm or in the cells that give rise to these reproductive cells and therefore is passed on to the next generation
Point Mutation
Single nucleotide being substituted
Synonymous Mutations
Silent Mutations
Nonsynonymous Mutations
Missense Mutations; messes with amino acids
Nonsense Mutations
Creates a stop codon
Frameshift mutations
an insertion or deletion of some number of nucleotides that is not a multiple of three causes a shift in the reading frame of the mRNA, changing all following codons
transposable elements
A DNA sequence that can replicate and move from one location to another in a DNA molecule; also known as transposon.
