genetics is the key to biology - brandeis university · genetics is the key to biology •genetics...

Chapter 1 Human Heredity by Michael Cummings ©2006 Brooks/Cole-Thomson Learning

Genetics Is the Key to Biology

• Genetics is the science of heredityand variation

• Study of how traits are passed fromone generation to the next


Fidelity and variation intransmission of genetic material


Genes

• Are the basic structural andfunctional unit of genetics

• Are sequences of nucleotides in DNA

• Control cells by directing proteinsynthesis


The Genetic Material - DNA(Deoxyribonucleic Acid)

•Composed of Nucleotide subunits

•Nucleotides are composed ofDeoxyribose (sugar)Phosphate groupBases

A (Adenine), T (Thymine)G (Guanine) or C (Cytosine)


DNA Is a Double Helix

DNA model.

Credit: © Science VU/NIH/Visuals Unlimited

35685

http://www.biologycorner.com/resources/DNA-colored.gif


The Genetic Code Is Universal

• Sequence of nucleotides determineshow the protein is produced from thegene

• Mutations are changes on the DNA


Gene Product = Protein

Fig. 1.2


Chromosomes

• Genes arearranged onchromosomes

Fig. 1.6

Karyotype


How Are Genes Transmitted fromParent to Offspring?

• Gregor Mendeldemonstrated theprinciples ofinheritance

• Conductedexperiments ontransmission oftraits in peas

Fig. 1.3


Approaches

• Transmission Genetics

• Pedigree Analysis

• Cytogenetics

• Molecular Genetics

• Population Genetics


Transmission Genetics

• Studies the pattern of inheritancethat results when traits are passedfrom generation to generation


Pedigree Analysis

• Family history isused toconstruct thepattern of how atrait is passedfrom generationto generation

Fig. 1.5


Cytogenetics

• Studieschromosomenumber andstructure

Fig. 1.6


Karyotype of Down’s syndrome

http://www.ucl.ac.uk/~ucbhjow/bmsi/lec7_images/47_xx_21.gif


Molecular Genetics

• Uses recombinant DNA technology toidentify, isolate, clone, and analyzegenes

• Tremendous impact in the last 40years

• Debate over social, legal and ethicalissues


Population Genetics• Identifies how much genetic variation

exists in populations• Investigates factors, such as migration,

population size, and natural selection, thatchange the frequency of a specific geneover time

• Coupled with DNA technology, investigatesevolutionary history and DNA identificationtechniques


Tracing ancestry of the Cohanim;Thomas Jefferson/Sally Hemings

http://www.pbs.org/wgbh/nova/israel/familygene.html

Lemba

Cohanim


Uses of Genetics

• Basic ResearchInformation about how genes functionWhat happens when they do not work?

• Applied ResearchCommercial products in healthcare,industry, and agriculture


Genetics and Social Policy

• Eugenics• Genetic Technology• Human Genome Project• Health Care• Recombinant DNA Technology


Genetic Technology

• Recombinant DNA

• Important forResearchGenetic testingGene therapyBiotechnology

Fig. 1.10


Human Genome Project

• Public and private research• Sequence the entire human genome• First draft in 2001 completed in 2003• 3 billion nucleotides• 35,000 genes• Genomics focuses on the organization

and function of the genomes


Health Care

• 10 million children andadults in U.S. sufferfrom a geneticdisorder

• Development ofgenetic testingidentifies individualsat risk and allows usto develop newtreatments

Fig. 1.11


Recombinant DNA Technology

• Genetically modified food - plants and animals• Production of human proteins to treat disease

How should this technology be used?

What are the ethical, legal, and social concerns?


Timeline of Recent Changes

genetics is the key to biology - brandeis university · genetics is the key to biology •genetics...

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