Lab 1 Genetics PDF - Titu Maiorescu University Year 3

Titu Maiorescu University Faculty of Dental Medicine Specialization: Dental Medicine Genetics, year 2 INTRODUCTION TO GENETICS Heredity = the transfer of characters or traits from the parents to their off springs is called heredity. Variat...

Titu Maiorescu University Faculty of Dental Medicine Specialization: Dental Medicine Genetics, year 2 INTRODUCTION TO GENETICS Heredity = the transfer of characters or traits from the parents to their off springs is called heredity. Variation = the differences between the characters or traits among the individuals of the same species. The main sources of variation are: GENETIC RECOMBINATION (occurring in meiosis), MUTATIONS and POPULATION MIGRATIONS. Importance of variation They enable the organism to adapt them in changing environment. 2. Variation forms the basis of heredity 3. They form raw material for evolution and development of new species. What is medical genetics? Human genetics is a branch of biology that studies how human traits are determined and passed down among generations. Any application of genetics to medical practice; Study of inheritance of diseases in families; Mapping of disease genes to specific locations on chromosomes; Analysis of molecular mechanisms through which genes cause disease; Diagnosis and treatment of disease; Genetic counseling. DNA: What Is It and What Does It Do? Humans and all other living things have DNA, which contains hereditary information; The information in your DNA gives your cells instructions for producing proteins which drive important body functions (digesting food, building cells, and moving your muscles); DNA is arranged like two intertwined ropes, in a structure called a double helix; Titu Maiorescu University Faculty of Dental Medicine Specialization: Dental Medicine Genetics, year 2 Each strand of DNA is made of four types of molecules, also called bases, attached to a sugar- phosphate backbone. The four bases are adenine (A), guanine (G), cytosine (C), and thymine (T); The bases pair in a specific way across the two strands of the helix: adenine pairs with thymine, and cytosine pairs with guanine. Genes are packaged into tightly wound lengths of DNA called chromosomes. Humans have 23 pairs of chromosomes. Sex chromosomes, identified as X or Y, determine whether a person is male or female; Each chromosome can be identified by its size and shape under a microscope; Each chromosome has a specific set of genes that is the same from person to person. One copy of each chromosome in a pair is inherited from each parent; Genes are small segments of DNA that have different functions. Many, but not all, genes make the proteins that our bodies need to function; Genes that code for proteins come in different versions called alleles. Titu Maiorescu University Faculty of Dental Medicine Specialization: Dental Medicine Genetics, year 2 In genetics, a locus (pl: loci) is a specific, fixed position on a chromosome where a particular gene is located. Traits are your observable characteristics. Many physical traits are genetic; Genetic differences give our bodies information that result in traits that differ from person to person; A difference from the expected sequence of a gene is called a variant or mutation; Variants can be inherited from your parents, or they can happen spontaneously; All of us have variants, but not all variants are harmful. Variants that are harmful can cause or increase our risk for certain diseases.