Gregor Johann Mendel 1822 1884 2010 2013 2010 2013 http www d umn edu cla faculty troufs anth1602 Important People Works Gregor Johann Mendel 1822 1884 Understanding Physical Anthropology and Archaeology 11th ed p 48 Gregor Mendel Understanding Humans 10th ed p 50 some basic terms Glossary inherited characteristics genetically determined traits e g eye color 11th Ed p 56 Glossary acquired characteristics learned traits e g the ability to write Glossary blending inheritance an earlier theory stating that offspring receive a combination of all characteristics of each parent through the mixture of their bloods Glossary blending inheritance an outmoded theory superseded by Mendelian genetics Glossary particulate inheritance physical traits are inherited as particles Mendel did not know what the particles were today they re recognized as particles like chromosomes and DNA chromosomes discrete structures composed of DNA and protein found only in the nuclei of cells The cell s three dimensional nature Understanding Humans 11th ed p 39 A model of a human chromosome Understanding Humans 11th ed p 44 Glossary phenotype genotype Glossary phenotype genotype Glossary phenotype the observable physical characteristics of an organism the things you can see the detectable expressions of genotypes Some examples of phenotypic variation among Africans San South African Understanding Humans 10th ed p 76 Some examples of phenotypic variation among Africans San South African Understanding Humans 10th ed p 76 Glossary phenotype genotype Glossary genotype includes genetic items you can not see gametes are reproductive cells eggs and sperm in animals developed from precursor cells in ovaries and testes Punnett square representing possible genotypes and phenotypes Understanding Humans 11th ed p 51 Punnett square representing possible genotypes and phenotypes Understanding Humans 11th ed p 51 Punnett square representing possible genotypes and phenotypes Understanding Humans 11th ed p 51 Punnett square representing possible genotypes and phenotypes Understanding Humans 11th ed p 51 Understanding Humans 11th ed p 50 Gregor Mendel The traits Mendel studied in peas Understanding Humans 11th ed p 49 The traits Mendel studied in peas Understanding Humans 11th ed p 49 www blc arizona edu courses 181gh rick genetics1 mendel html AA aa Punnett square representing possible genotypes and phenotypes and their proportions in the F2 generation Understanding Humans 10th ed p 53 Conceptos b sicos Mendel Experiment 1 Aa Aa Punnett square representing possible genotypes and phenotypes and their proportions in the F2 generation Understanding Humans 10th ed p 53 Conceptos b sicos Mendel Experiment 1 3 1 ratio of Yellow Green in F2 http nitro biosci arizona edu courses EEB195 2007 Lecture02 Lecture02 html Results of crosses when only one trait at a time is considered Understanding Humans 11th ed p 49 AA aa Aa Aa Genotypes and phenotypes in the F1 generation Conceptos b sicos Mendel Experiment 1 AA aa AA aa Aa Aa Aa AA 2 Aa aa 25 50 25 AA Aa aa 75 AA or Aa 25 aa Punnett square representing possible genotypes and phenotypes and their proportions in the F2 generation Understanding Humans 11th ed p 51 75 25 Punnett square representing possible genotypes and phenotypes and their proportions in the F2 generation Think Quest Introduction to Genetics Glossary dominant describing a genetic trait governed by an allele one of a group of genes that can be expressed in the presence of another different allele Genotypes and phenotypes in the F1 generation Conceptos b sicos Mendel Experiment 1 Glossary recessive describing a genetic trait that is not expressed in heterozygotes Aa Tt Glossary recessive for a recessive allele to be expressed there must be two copies of the allele i e the individual must be homozygous aa tt Crosses with Two traits http nitro biosci arizona edu courses EEB195 2007 Lecture02 Lecture02 html Glossary sex linked trait traits carried by genes located on the X or Y sex chromosomes genetically normal females XX genetically normal males XY Glossary sex linked trait most X linked characteristics are recessive in females which means that unless they are present on both X chromosomes of a female the trait is carried but not expressed Glossary sex linked trait males with only one X chromosome more commonly exhibit such traits phenotypically e g hemophilia e g red green color blindness http news bbc co uk 2 hi science nature 8297467 stm http news bbc co uk 2 hi science nature 8297467 stm http sciencenow sciencemag org cgi content full 2009 1008 2 perth uwlax edu faculty howard BIO101 DNA translation sld002 htm Diana Kate Middleton brie medlabscience med ualberta ca de genetics 70gen hemophil html sex linked trait aka Holandric Inheritance Y linked traits which are directly involved with determining maleness are manifested only by males known examples are rare but probably include the long hairs on the ear rims of some adult males in India Ceylon Israel and aboriginal Australia Important People Works Hugo de Vries 1848 1935 in 1900 rediscovered Mendel s work on plant hybrids Hugo de Vries 1848 1935 Canal houses in Amsterdam Mimicry Minnesota Department of Natural Resources Mimicry Predaatio saaliin ja saalistajan kilpajuoksu so where did those pink flowers Come from Penn State Biology Department Incomplete dominance in snapdragon color http courses bio psu edu fall2005 biol110 tutorials tutorial5 htm In Mendel s experiments offspring always looked like one of their two parents due to the complete dominance of one allele over the other This is not always the case because some genes display incomplete dominance and individuals with heterozygous alleles exhibit a phenotype intermediate between those with homozygous alleles Penn State Biology Department http courses bio psu edu fall2005 biol110 tutorials tutorial5 htm In Mendel s experiments offspring always looked like one of their two parents due to the complete dominance of one allele over the other This is not always the case because some genes display incomplete dominance and individuals with heterozygous alleles exhibit a phenotype intermediate between those with homozygous alleles Penn State Biology Department http courses bio psu edu fall2005 biol110 tutorials tutorial5 htm Since neither allele dominates over the other the use of an uppercase and lowercase version of the same letter is inappropriate In this example the character i e flower color is indicated by a letter