Genetics Primer

Who is Gregor Mendel? “You look just like your mom did when she was your age!” The father of “modern genetics” First studied inheritance patterns using garden pea plants He observed that traits were inherited as separate units. His work formed the foundation for the era of modern genetics, the study of the function and behavior of genes. “You’ve got your dad’s curly hair.”

Genes The basic units of heredity. Every living organism carries a set of genes inside its cells. Biochemical information that is transmitted from generation to generation by DNA (deoxyribonucleic acid). Our genes are the genetically unique blueprint that makes us who we are. The color of a flower, your pet’s coat pattern, the ability to have musical talent Only identical twins have genes that are exactly the same!

Who are geneticists? Scientists who study genes and their variations. Their goal is to: understand how information is encoded in genes and how it is transmitted from one generation to the next. They also study how disease may be caused and how to manipulate genes (genetic engineering)

Why is Genetics Important? Current issues Cloning Treating disease with stem cell and gene therapy Conducting genetic testing for human disease Understanding products with risk-vs.-benefit controversies ( UV rays, radiation, food additives, agricultural chemicals)

Currently, Scientists are creating genetic maps, a process to chart position of known genes and other markers relative to each other. Now using genetic engineering techniques they are mapping the genomes of many species. Genome- the whole hereditary information of an organism that is encoded in the DNA or an organism Why: understand disease, appropriate treatment plans, design of medication

Mendel’s Rules: A Pattern of Inheritance Genotype: combination of genes that code for a trait Phenotype: describes the physical manifestation of that trait 1. that the inheritance of each trait is determined by genes that are passed on to descendants unchanged 2. that an individual inherits one such unit from each parent for each trait 3. that a trait may not show up in an individual but can still be passed on to the next generation.

Exceptions to Mendel’s Rule Incomplete dominance: the inheritance of a dominant and recessive trait results in a blending Quantitative inheritance: Multiple genes control the trait ( ex. Skin color) Multiple genes: Certain traits are controlled by multiple genes that have complex rules of dominance Gene linkage: When certain genes occur close together on the same chromosome, they can act as one prior to dividing in development Sex-linked traits: Because the sex chromosomes differ from a male and female different traits may be carried ( Hemophilia, color blindness)