Genetics

Ch 14: Mendel and the Gene Idea Overview: Drawing from the Deck of Genes What genetic principles account for the passing of traits from parents to offspring? The ?blending? hypothesis is the idea that genetic material from the two parents blends together (like blue and yellow paint blend to make green) The ?particulate? hypothesis is the idea that parents pass on discrete heritable units (genes) This hypothesis can explain the reappearance of traits after several generations Mendel documented a particulate mechanism through his experiments with garden peas Concept 14.1: Mendel used the scientific approach to identify two laws of inheritance Mendel discovered the basic principles of heredity by breeding garden peas in carefully planned experiments

16 - The Molecular Basis of Inheritance Ch. 16: The Molecular Basis of Inheritance Concept 16.1: DNA is the genetic material Early in the 20th century, the identification of the molecules of inheritance loomed as a major challenge to biologists When T. H. Morgan?s group showed that genes are located on chromosomes, the two components of chromosomes?DNA and protein?became candidates for the genetic material A chromosome consists of a DNA molecule packed together with proteins The bacterial chromosome is a double-stranded, circular DNA molecule associated with a small amount of protein Eukaryotic chromosomes have linear DNA molecules associated with a large amount of protein In a bacterium, the DNA is ?supercoiled? and found in a region of the cell called the nucleoid