Genetics Vocabulary Terms Intro to Genetics & Mendel Genetics The study of how traits are passed from generation to generation Gregor Mendel The “Father of Genetics.” Trait A characteristic (physical, personality, medical) When the offspring always looks like parent True Breeding Hybrid Looks like a mix of two parents when they are cross-pollinated Dominant Trait is one that can hide a recessive trait (indicated by capital letter) Recessive Trait can be hidden by a dominant trait (indicated by a lower case letter) Gene Part of a chromosome and codes for a trait Allele Segregation Gametes A different version of a gene The process of separating alleles The sex cells (egg & sperm) Genetics Vocabulary Terms PROBABILITY VOCABULARY Probability Punnett Square The chance of something happening Penny: Heads or Tails 50% or 1/2 A tool used to figure out possible outcomes Homozygous When both alleles look the same (AA or aa) Heterozygous When both alleles do not look the same (Aa) Phenotype The “physical appearance” (Ex: Brown Hair, Tall, Short, Wrinkled, Round) Genotype The “gene type” or allele letters (Ex: TT, Tt, tt) Genetics Vocabulary Terms Gene Expression Independent Assortment Incomplete Dominance Co-Dominance How one trait that is expressed does not affect the other (Ex: hair color and eye color) When there is a blending of traits and a totally new trait is observed (ex: Red flowers x White flowers = Pink flowers) When both alleles are expressed equally and one does not dominate over the other (ex: Blood types AB) Multiple Alleles When more than the usual 2 alleles are present (ex: IA IB i) Polygenic Traits Many genes working together giving wide variety of outcomes (ex: height, skin color, hair color) Genetics Vocabulary Terms Human Heredity Human Heredity Karyotype Sex Chromosome Autosomes Focusing on human traits A picture of all chromosomes matched up and helps to show abnormalities The 23rd pair of chromosomes and determines gender XX=Female XY=Male All the other 22 pairs of chromosomes other than sex chromosomes Sex-Linked Traits Sex-linked gene/trait Traits that are linked to the sex chromosomes such as hemophilia and colorblindness Non-disjunction When chromosome pairs do not separate during Anaphase I Genetics Vocabulary Terms