Genetics Unit 1

genetics

the study of heredity and variation in living organisms

heredity

the transmission of traits from one generation to the next

variation

the difference in trait among individuals within a population

medicine

understanding and treating genetic diseases with personalized pharmacogenomics

agriculture

improving crop yields, disease resistance, nutritional value

biotechnology

genetic engineering, gene therapy, forensic DNA analysis

basic biology

understanding basic life processes, evolution, and biodiversity

pangenesis

particles from all parts of the body contribute to reproductive cells

Hippocrates

theory of pangenesis was credited to him

homunculus

miniature humans in sperm and eggs

blending inheritance

parental traits mix to form an intermediate; most widely accepted theory before Mendel

gregor mendel

austrian monk, botanist, and mathematician; performed experiments with garden pea plants; proposed principles of inheritance

Mendel’s principles of inheritance

each pea plant body cell contains 2 copies of the genes that control flower colors; only 1 copy of the gene enters into the gametes; factor for flower colors comes in 2 variants or alleles

William Bateson

rediscovered Mendel’s work and coined the term “genetic”

Thomas H. Morgan

used fruit flies to prove that genes are located on chromosomes; proved the chromosome theory of inheritance

simple traits

what Mendel observed; followed the 3:1 segregation ratio; controlled by a single gene

continuous traits

many traits show a continous range of outcomes; controlled by multiple genes

Ronald Fisher

resolved how Mendelian genes explained inheritance of variable traits; proposed that continuous traits are controlled by multiple Mendelian genes

multifactoral hypothesis

found by Ronald Fisher; continous traits are controlled by multiple genes

Edward Tatum and George Beadle

proposed that genes encode enzymes to perform metabolic functions within the cells; known as the one-gene-one-enzyme hypothesis

Oswald Avery, Colin MacLeod, and Maclyn McCarty

propsed that genes are made of DNA; DNA extratced from a virulent strain of bacteria carried necessary genetic information to transform a nonvirulent strain into a virulent strain

Alfred Hershey and Martha Chase

confirmed theory that genes are made of DNA

James Watson and Francis Crick

determined the molecular structure of DNA

DNA structure

side of the ladder are composed of sugar and phosphate groups; rungs of the ladder are composed of nitrogenous bases

Francois Jacob and Jacques Monod

demonstrated that genes have regulatory elements that control gene expression using E. coli; specific regulator proteins bind and act to acitvate or repress expression of a gene

central dogma of molecular biology

basic flowchart for the decoding of DNA into 20 amino acids to build proteins

model organisms

species used in experimental biology with the presumption that what is learned from the analysis of that spcies will hold true for other species

fruit flies

one of the most impoerant model organisms for genetic research

features of a good model organism

small and easy/inexpensive to maintain; short generation time; small genome; easy to cross/mate and produce large numbers of offspring

genes

fundamental units of heredity consisting of specific sequences of DNA that rpovide instructions for building proteins which determine an organisms’ traits

alleles

one of two or more alternative versions of a genes, found at the same position on a chromosome, that codes for different versions of a trait

chromosomes

contain body’s genetic blueprint, DNA