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Concepts and Applications Seventh Edition. Powerpoint Lecture Outline. Human Genetics. Ricki Lewis Prepared by Mary King Kananen Penn State Altoona. Ch 1 vocab Part 1. Biobank Scavenger Hunt- by group. Each person: Make a list of these categories and record the
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Concepts and Applications Seventh Edition Powerpoint Lecture Outline Human Genetics Ricki Lewis Prepared by Mary King Kananen Penn State Altoona Ch 1 vocab Part 1
Biobank Scavenger Hunt- by group Each person: Make a list of these categories and record the information you find for each….. • Name of Biobank. • Name of (1)Director/CEO/President/Founder. • Mission statement/slogan/logo. • Location. • Years of service. • Services provided. • Additional information (name at least 3). Project Assignment: Due Monday, 10/20/14 Will post example and rubric to my webpage
Genetics • Is a life science • It is the study of inherited variation and traits • Genes are the units of heredity • Genes are composed of Deoxyribonucleic Acid (DNA) • Traits are produced by an interaction between the genes and the environment
Genes • Contain the instructions within the cells for protein production Figure 1.1
TheGenome • Is the complete set of genetic information for an organism • It includes: • All of the genes present in an organism and • Other DNA sequences that do not encode genes • Human genome was sequenced in 2000
Genetic Testing • Uses new technology • Detects health-related genetic variants • May be used • To prevent, delay, control, or treat symptoms • Gain information on risk of genetic diseases and for pre-pregnancy testing • Personalize medical treatment
Steps in Genetic Testing Figure 1.2
Genetic Counseling • Genetic counselor recommends tests and explains the findings from the laboratory testing • Confidentiality is important • Laws prevent employers and insurers from discriminating against anyone based on genetic information
Examples of Genetic Tests • Cystic fibrosis • Certain cancers • Inherited forms of Alzheimer's • Type 2 diabetes • Others
Review Question 6 – pg. 18 • Health insurance forms typically ask for applicants to list existing or preexisting symptoms. How do results of a genetic test differ from this?
Levels of Genetics Figure 1.3
Deoxyribonucleic Acid (DNA) • A double stranded polymer consisting of a chain of nucleotides • Deoxyribonucleotide components: • Phosphate • Sugar: Deoxyribose • Base: • Guanine G Adenine A • Thymine T Cytosine C • The sequence of the bases code for the amino acid sequence in a protein
Ribonucleic Acid (RNA) • Single stranded polymer of ribonucleotides • Ribonucleotides components: • Phosphate • Sugar: Ribose • Base: • Guanine G Adenine A • Uracil U Cytosine C • Several types • Uses information on DNA to construct proteins
Genome • Only 1.5% of the DNA in the human genome encodes protein • Rest includes highly repeated sequences with unknown functions • Includes about 24,000 protein encoding genes • Cataloged in database • Online Mendelian Inheritance in Man (OMIM)
Genes • Alleles are variants of genes • They form by mutation • Mutations in sperm or egg cells are passed on to the next generation • May be positive, negative, or neutral • Examples • resistant to HIV • myostatin mutation
Review Question 5 – pg. 18 • Mutations are often depicted in the media as being abnormal, ugly, or evil. Why is this not necessarily true?
Variations • Polymorphisms are variations in the DNA sequence that occur in at least 1% of the population • Single nucleotide polymorphisms (SNPs) are single base sites that differ among individuals and are important as markers
Chromosomes • Composed of DNA and protein • Found in the nucleus of the cell • Human cells have 46 chromosomes • 22 pairs of autosomes • The sex chromosomes X and Y • Females have two X chromosomes • Males have one X and a Y
A Karyotype is a chart of the chromosomes organized by the size of the chromosome pairs. Figure 1.3
Cells • All cells with a nucleus in the body contain the same genetic information • Differentiation causes cells to differ in appearance and function. This is controlled by variation in gene expression. • Stem cells are less specialized
Levels of Organization • Cells • Tissues • Organs • Organ systems • Organism
Individual • The genotype of an individual is the alleles they carry • The phenotype is the visible trait • Dominant alleles are expressed if the individual carries one or two copies of the allele • Recessive alleles are only expressed if the individual carries two copies of the allele
The Family • Inheritance of traits can be observed in families. • A pedigree indicates the structure of a family • schematically. Figure 1.3
Applied Question 4 pg. 18 • In search for a bone marrow transplant, why would a patient’s siblings be considered before first cousins? • Answer: An individual shares more genes with a sibling (1/2) than with a first cousin(1/8).
A Population • Is a group of interbreeding individuals • The gene pool is the alleles in a population • Evolution is the changing allelic frequencies in populations over time. Figure 1.3
Evolution • Comparison of DNA sequences indicates the amount of similarity between two species. • 98% of human DNA sequences are shared with chimpanzees. • Humans share genes with mice, fish, fruit flies, yeast, and bacteria. Figure1.5
Variation in the Human Population • Two random people share approximately 99.9% of their genome • Concept of “race” as defined by skin color is a social, not a biological, concept • Studies indicates humans arose in Africa and migrated across the globe with relatively little change.
Review of Genetic Terms Table 1.1
Most Genes Do Not Function Alone • Mendelian traits are determined by a single gene • Most traits are multifactorial and not controlled by a single gene. They are influenced by more than one gene and the environment • Some illnesses may occur in different forms: Mendelian, multifactorial, and non-inherited
Review Question 4 – pg. 18 • Cystic fibrosis is a Mendelian trait; height is a multifactorial trait. How do the causes of these characteristics differ?
Genetic Risk Absolute risk the probability that an individual will develop a condition or trait Relative risk the likelihood that an individual from one group will develop a condition in comparison to another group (usually the general population) Empiric risk risk determined by observing incidence of a trait in the population Risk factor a situation that alters incidence of a disease (or trait)
Relative Risk Figure 1.7
Applications of Genetics • DNA profiling compares DNA sequences to • Establish relationships • Forensics • Biobanks Box Table 1.1
Applications of Genetics • Historical • Common origins Figure 1.9
Applications of Genetics Health care • Prediction of disease • Development of treatments • Family planning
Applications of Genetics Agriculture–pg.15 • Crop and animal breeding • Genetically modified foods • Pest management Figure 1.12
Applications of Genetics • Ecology