ch01Overview-of-Genetics.ppt.pptx

Human Genetics Concepts and Applications Tenth Edition RICKI LEWIS Overview of 1 Genetics PowerPoint® Lecture Outlines Prepared by Johnny El-Rady, University of South Florida Copyright ©...

Human Genetics Concepts and Applications Tenth Edition RICKI LEWIS Overview of 1 Genetics PowerPoint® Lecture Outlines Prepared by Johnny El-Rady, University of South Florida Copyright ©The McGraw-Hill Companies, Inc. Permission required for reproduction or display  Genetics Is the study of inherited traits and their variation Is a life science that should not be confused with genealogy Figure 1.1 Is also an informational science that is having a huge societal impact 2  Genes Contain the instructions within the cells for protein production Genes are composed of deoxyribonucleic acid (DNA) Traits are produced by an interaction between the genes and their environment Figure 1.1 3  The Genome Is the complete set of genetic information for an organism It includes all of the genes present in an organism - And also DNA sequences that do not encode genes Genomics is a field that analyzes and compares genomes of different species 4  Levels of Genetics Figure 1.2 5  Deoxyribonucleic Acid (DNA) A double-stranded polymer consisting of a chain of nucleotides Deoxyribonucleotide components: - Phosphate - Sugar: Deoxyribose - Base: Adenine A Guanine G Thymine T Cytosine C The sequence of the bases code for the amino acid sequence in a protein 6  Box, Figure 1 Reading1.1, Figure 1 7  Ribonucleic Acid (RNA) A single stranded polymer of ribonucleotides Ribonucleotide components: - Phosphate - Sugar: Ribose - Base: Adenine A Guanine G Uracil U Cytosine C Exists in several types Uses information on DNA to construct proteins 8  Box, Figure 2 Reading 1.1, Figure 2 9  Genes Alleles are variants of genes They form by mutation Mutations in sperm or egg cells are passed on to the next generation Mutations may be positive, negative, or neutral 10  Chromosomes Composed of DNA and protein Found in the nucleus of the cell Human somatic cells have 46 chromosomes - 22 pairs of autosomes - A pair of sex chromosomes - Females have two X chromosomes - Males have one X and a Y 11  Karyotype A chart displaying the chromosome pairs from largest to smallest Figure 1.2 Figure 1.2 12 Table 1.1 13  Cells A human body contains approximately 50-100 trillion cells - All cells except RBCs contain the same genome Differentiation causes cells to differ in appearance and function - Controlled by variation in gene expression Stem cells are less specialized and can become many different cell types 14 Levels of Biological Organization Figure 1.3 Figure 1.3 15  Individual The genotype of an individual refers to the alleles they carry The phenotype is the visible trait A dominant allele is expressed if the individual carries just one copy A recessive allele is only expressed if the individual carries two copies 16  The Family Individuals are genetically connected into families A pedigree is a diagram used to study traits in families - Can be used to trace multiple genes or genes with large environmental component - Will be discussed in detail in Chapter 4 17 Mendelian vs. Multifactorial Traits Mendelian traits are determined by a single gene - Their recurrence is predicted based on Mendel’s laws Multifactorial traits are determined by one or more genes and the environment - Predicting their recurrence is much more difficult Most traits are multifactorial 18 Mendelian vs. Multifactorial Traits Figure 1.5 19  Applications of Genetics Genetics impacts many areas of our lives DNA profiling (DNA fingerprinting) looks at SNPs and short repeated DNA sequences - It has applications in: - Forensics - History and ancestry 20  Forensics Identification of victims of natural disasters or terrorist attacks Matching the DNA of suspects to samples left at the crime scene Helping adopted individuals locate blood relatives 21  History and Ancestry DNA analysis can flesh out historical details - Revealing the offspring of Thomas Jefferson and Sally Hemmings - Revealing the origins of the Jewish Lemba of South Africa 22  History and Ancestry Figure 1.6 Figure 1.7 Figure 1.7 23  Health Care Pharmacogenomics is a field that identifies individual drug reactions based on genetics 24  Health Care Analysis of single-gene illnesses reveals many differences from other diseases 25  Health Care Diseases are increasingly being described in terms of gene expression patterns Tracking gene expression can reveal new information about diseases and show how diseases are related to each other - This is not obvious via traditional medicine 26  Agriculture Traditional agriculture is the controlled breeding of plants and animals Biotechnology is the use of organisms or their parts to produce goods and services Genetically-modified (GM) organisms have new genes or over- or under-express their own genes 27 Figure 1.9 28  Ecology Metagenomics is a field that involves sequencing all of the DNA in a habitat - The Sargasso Sea - The Human Microbiome Project Metagenomic studies may be used to reconstruct ecosystems 29