Chapter 3: Genetics Flashcards
genetic sampling: pre 1960
breeding experiments only
genetic sampling: 1960
- protein electrophoresis
- direct measure of genetic variation, but lethal sampling
genetic sampling: 1980
PCR coupled with direct analysis of DNA allowed non-invasive sampling to occur
Polymerase Chain Reaction
put isolated DNA in tubes with primers, nucleotides, and Taq polymerase
each cycle of PCR
- PCR machine separates DNA strands (denature)
- then cools to anneal (bind) primers (DNA fragments)
- then heats a bit to attach nucleotides (extend)
with PCR, DNA can be obtained non-invasively from:
- old samples
- museomics
- field samples of low quality &/or quantity
non invasive techniques: old samples
- 120 million year old weevil
- 20,000 year old saber-toothed cat bones
non invasive techniques: field samples
- feathers
- fish scales
- feces
- urine
- egg shells
- hairs
- sloughed skin
- eDNA
gene
stretched of DNA along a chromosome that codes for a protein or regulates other genes
locus
where a gene is on the chromosome
allele
different form of a gene (varying in nucleotide sequences)
genome
the complete set of genes in a cell/organism
genotype
the identity of alleles at a locus (genetic makeup)
phenotype
observable characteristics produced by genotype & environment
heterozygosity
proportion of individuals in a population that are heterozygous at a locus