1. Ch. 1
Overview of Genetics

2. Genetics Is the study of inherited traits and their variation
Is a life science that should not be confused with genealogy
Is also an informational science that is having a huge societal impact
Figure 1.1

3. 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

4. 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

6. Levels of Genetics

7. 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

8. Box, Figure 1
Reading1.1, Figure 1

9. 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

10. Box, Figure 2
Reading 1.1, Figure 2

11. The Human Genome Only 1.5% of our DNA encodes protein
- About 20,325 protein-encoding genes in all
Rest of the human genome includes highly repeated sequences with unknown functions
Genes known to cause disorders or traits are cataloged in a database
- Online Mendelian Inheritance in Man (OMIM)
Proteomics is a field that studies the proteins made in a cell

12. 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

13. 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
- Can cause disease or act as genomic markers

14. Research
Genome-wide association studies track SNP patterns among individuals who share a particular trait or disorder
Gene expression profiling measures which genes are more or less active in particular cell types

15. 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 & a Y

16. Karyotype
A chart displaying the chromosome pairs from largest to smallest
Figure 1.2
Figure 1.2

17. 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

18. 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

19. 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

20. A Population
Is a group of interbreeding individuals
The gene pool is the sum of all alleles in a population
Evolution is the changing allelic frequencies in populations over time

21. Evolution
Genome comparisons among species reveals evolutionary relationships
- The more similar the sequences are, the more recent the divergence from a common ancestor
98% of human DNA sequences are shared with chimpanzees
Humans share genes with mice, pufferfish, fruit flies, yeast, and even bacteria

22. Figure 1.4
Figure 1.4

23. 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

24. Mendelian vs. Multifactorial Traits
Figure 1.5

25. Genes and Disease Risk
Genetic determinism is the idea that the expression of an inherited trait is inevitable
This may be harmful or helpful, depending on its application
- As part of a social policy, it is disastrous
- Knowing genetic risks can help us make good choices

26. 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

27. 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

29. 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

30. History and Ancestry
Figure 1.6
Figure 1.7
Figure 1.7

31. Health Care
Pharmacogenomics is a field that identifies individual drug reactions based on genetics

32. Health Care
Analysis of single-gene illnesses reveals many differences from other diseases

33. 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

34. Genetic Testing and Treatment
Tests to identify about 1,200 single-gene disorders have been available for years
- Direct-to-consumer (DTC) genetic testing
The Genetic Information Non-discrimination (GINA) act was passed in the US in 2008
Genome information is useful for developing treatment to genetic and infectious diseases

35. Gene therapy attempts to correct certain genetic disorders.

36. 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

37. These animals make glowing fluorescent protein (gene from a jellyfish)
A transgenic organism harbors a gene or genes from a different species.
Transgenic rice manufactures beta-carotene and stores twice as much iron as unaltered rice.
These animals make glowing fluorescent protein (gene from a jellyfish)
Goats produce spider silk protein in their milk

38. A Global Perspective
Genetics and genomics are spawning technologies that may vastly improve the quality of life
Human genome information has tremendous potential for the entire globe
- Individual nations are using approaches that exploit their particular strengths

39. A Global Perspective Nation Program China
The genome of 100 people are being sequenced.
Gambia
A DNA databank has samples from 57,000 people.
India
A national databank stores DNA from 15,000 people. A company is genotyping the entire Parsi population of 69,000. Law prevent foreign researchers from sampling tissue from Indians without permission.
Mexico
The National Institute of Genomic Medicine has genotyped 1,200 people o look for correlations to common diseases. Legislation requires approval for foreign researchers to sample DNA from Mexicans.
South Africa
Studies of human genetic diversity among indigenous tribes and susceptibility to HIV and tuberculosis among many populations are underway.
Thailand
A database stores information on genetic susceptibility to dengue fever, malaria, other infectious diseases, and posttraumatic stress disorders from the 2004 tsunami.