Definitions Flashcards
(31 cards)
Trait
Characteristic feature of an organism
Genotype
Genetic variant present at a given location in the genome
Phenotype
An individuals observational trait
Chromosome
A structure composed of DNA and proteins that bears genetic info
Gene
A section of DNA that codes for a polypeptide or RNA
Gene locus
A specific location of a gene along a chromosome
Allele
Different molecular forms of the same gene
Ploidy
Number of copies of a genome an organism has
Wild type
An allele that is common, thought of as the “default” phenotype
Polymorphic gene
Gene with multiple allele
Incomplete dominance
Heterozygotes with a blended pheontype
Pleiotropic allele
Allele with multiple phenotypic effects
Epistasis
Phenotypic expression of one gene is influenced by products of other genes
Penetrance
Proportion of individuals with a genotype that develop the expected phenotype
Expressivity
Degree to which a phenotype is expressed in an individual
Qualitative traits
Discrete qualities controlled by alleles at a single locus
Quantitative traits
Show continuous variation, can be influenced by genes at many loci as well as environment
Thomas Hunt Morgan
Pioneered study of fruit fly Drosophila
Hemizygous
A gene that is present in a single copy in an otherwise diploid individual
Lyonization
Early in embryo development, one of two X chromosomes inactivates by supercooling into Barr body. Won’t be unanimous choice between all cells in body
DNA key features
• Double stranded helix
• Right handed helix
• Antiparallel
• Strands held together by complimentary base pairing
• Outer edge of bases hold major & minor groups
Semiconservative replication
Each parent strand is a template, new molecules have one old and one new strand
Mechanisms of DNA repair
• Proofreading
• Mismatching repair
• Excision repair
• Homologous recombination
PCR mixture
• sample of double stranded DNA
• two artificially synthesised primers
• four dNTPs
• DNA polymerase
• salts & pH buffer
