Changes in the Genetic Code Flashcards
Gene pool
the total of all the alleles of all the genes in the individuals in a population
Adaptive advantage
a difference in structure, physiology, or behaviour that gives an organism a better chance of survival
Mutation
a permanent change in the genetic code (DNA) of a cell
Somatic cell mutation
a mutation that occurs in a body cell; passed on to daughter cells, but not to the next generation of individual organisms
Germ line mutation
a mutation that occurs on a gamete and can be passed to the next generation
Point mutation
a permanent change in the genetic material of a cell that affects one or just a few nucleotides
Chromosomal mutation
a mutation that involves the deletion, insertion, or crossing over of chromosomes
Substitution
a type of point mutation in which one nucleotide is switched fro another nucleotide in a DNA sequence
Insertion
a type of point mutation in which one nucleotide is added to the DNA sequence, causing a frameshift mutation
Deletion
a type of point mutation in which nucleotide is removed from a DNA sequence, causing a frameshift mutation
Frameshift mutation
permanent change in the genetic material of a cell caused by the insertion or deletion of one of two nucleotides, so that the entire reading frame of the gene is altered
Induced mutation
permanent change in genetic material caused by a mutagen outside the cell
Mutagen
substance or event that increases the rate of mutation in an organism
Physical mutagen
agent that can forcibly break a nucleotide sequence, causing random changes in one or both strands of a DNA molecule (e.g. X-rays)
Chemical mutagen
a molecule that can enter the cell nucleus and induce a permanent change in the genetic material of the cell by reacting chemically with DNA (e.g. nitrites)
