Chapter 12 Flashcards
Species
A group of individuals that share many characteristics an are able to interbreed under natural conditions to produce fertile offspring.
Population
A group of organisms of the same species living together in a particular place at a particular time.
Allele
An alternative form of a gene.
Gene pool
Sum of all the alleles in a given population.
Mutation
A change in a gene/chromosome leading to new characteristics in an organism.
Gene
A section of DNA which codes for a protein (one characteristic).
Gene mutation
An alteration to a single gene.
Chromosome
Carries hereditary information, all human body cells have 23 pairs of chromosomes.
Chromosomal mutation
Change to a structure and number of chromosomes in an organism.
Mutagen OR mutagenic agents
Environmental agent that increases the rate of mutation.
Somatic mutation
Occurring in a gene in a BODY CELL (not a gamete/sex cell).
Germline mutation
A mutation in the gamete that becomes incorporated into the DNA of every cell in the body of the offspring.
Point mutation
Change in just one of the bases in a DNA molecule.
Trisomy
A chromosomal mutation in which there are three chromosomes instead of a pair -> Down syndrome aka trisomy 21 (an extra copy on the 21st chromosome).
Monosomy
A chromosomal mutation in which there is 1 chromosome instead of a pair -> e.g Turner’s syndrome - only one X chromosome (in females).
If only part is missing = partial monosomy.