Understanding Genetics: DNA, Genes, and Their Real-World Applications
Dr. David Sadava is Adjunct Professor of Cancer Cell Biology at the City of Hope Medical Center in Duarte, CA, and the Pritzker Family Foundation Professor of Biology, Emeritus, at The Claremont Colleges. Professor Sadava graduated from Carleton University as the science medalist with a B.S. with first-class honors in biology and chemistry. A Woodrow Wilson Fellow, he earned a Ph.D. in Biology from the University of California, San Diego. Following postdoctoral research at the Scripps Institution of Oceanography, he joined the faculty at Claremont, where he twice won the Huntoon Award for Superior Teaching and received numerous other faculty honors. He has been a visiting professor at the University of Colorado and at the California Institute of Technology. Professor Sadava has held numerous research grants and written more than 55 peer-reviewed scientific research papers, many with his undergraduate students as coauthors. His research concerns resistance to chemotherapy in human lung cancer, with a view to developing new, plant-based medicines to treat this disease. He is the author or coauthor of five books, including the recently published 10th edition of a leading biology textbook, Life: The Science of Biology, as well as a new biology textbook, Principles of Life.
01: Our Inheritance
From earliest history, humans have bred plants and animals for desirable and productive characteristics. And they have wondered how it all works. Professor Sadava gives us a brief, fascinating history of genetics and introduces us to the three major unifying ideas in biological science, ideas which form the cornerstone of this course.
02: Mendel and Genes
Monk and scientist Gregor Mendel, working in the late 1800s, learned through pea-plant experiments that each parent's characteristics were particulate, that is, chemically independent. His meticulous research-the beginning of modern genetics-languished for nearly 40 years before its value was discovered.
03: Genes and Chromosomes
Where do you find a gene? Within each living cell is a nucleus, within the nucleus is a chromosome, and on that chromosome is the gene. Beginning with the cell, the unit of biological continuity, this lecture describes the physical and chemical environment of the gene. It shows us that you don't have to be a geneticist to figure out genetics, as a group of rabbis in A.D. 500 learned.
04: The Search for the Gene-DNA
How did research on smoking and lung cancer help scientists figure out that DNA, the genetic material, was damaged in the tumor cells? Professor Sadava tells us how scientists first determined what they were looking for and then found the circumstantial evidence that pointed to DNA.
05: DNA Structure and Replication
The double helix model for DNA is one of the most recognizable scientific icons of our time. This lecture details how Watson and Crick built on the work of earlier researchers to solve the puzzle of the structure of DNA-the double helix.
06: DNA Expression in Proteins
Proteins are made up of chains of 20 amino acids ordered in a particular sequence for each protein. Humans cannot produce eight of those 20 amino acids, although we still need them for proper nutrition. Professor Sadava explains what proteins are, how they relate to DNA, and why they're significant to us.
07: Genes, Enzymes, and Metabolism
Enzymes, which are encoded in our genes, are responsible for most chemical conversions in our bodies. An enzyme sends a signal that creates a biochemical pathway for the process of changing something we consume into something else we need or must get rid of. This lecture explains how metabolism is hard-wired into our genes.
08: From DNA to Protein
In 2004 traces of a poison called ricin were found in a U.S. Senate mailroom. Only 1/10,000 of an ounce of ricin can be fatal. Ricin's enzymes inhibit gene expression; as a result, when ricin is introduced to animal cells, the cells die. This lecture explains how gene expression happens.
The 24,000 genes that are expressed in humans represent only 2 percent of the entire genome. This lecture explains the history of the Human Genome Project, which grew out of scientists' studies on the effects of radiation on the survivors of the atom bombs in Hiroshima and Nagasaki.
10: Manipulating Genes-Recombinant DNA
By studying how bacteria successfully protect themselves from an attacking virus, scientists discovered that bacteria make an enzyme that recognizes a particular DNA sequence in the virus and cuts the DNA strand at that sequence. As a result of this discovery, scientists learned to splice DNA, creating recombinant DNA, which was initially controversial and now holds vast possibilities for the futu...
11: Isolating Genes and DNA
Learn how genetics is used to understand and work toward the cure of a particular disease. After methods for analyzing DNA and chromosomes were developed rapidly in the 1980s, the scientific community tried a new approach called reverse genetics. As a result of this work, scientists isolated the gene that is missing in individuals who have muscular dystrophy.
12: Biotechnology-Genetic Engineering
Insulin that treated individuals with diabetes, whose bodies don't create insulin (or enough of it) on their own, used to come from animals. Animal insulin, however, contains a different sequence of amino acids, so some people's bodies rejected it. The method of manufacturing insulin developed at a California hospital is how all insulin used to treat diabetics is now made.
13: Biotechnology and the Environment
We can use bacteria to solve man-made problems, such as landmines, oil spills, toxic waste, and pollution. Scientists are working to genetically engineer organisms whose traits can be useful in cleaning up our world.
14: Manipulating DNA by PCR and Other Methods
What's the real science behind the dinosaurs that come to life in the movie Jurassic Park? Professor Sadava explains how scientists extract DNA from fossils, and what we can learn about ancient creatures from their genes. This lecture also covers DNA sequencing methods....
15: DNA in Identification-Forensics
In the aftermath of the 2004 tsunami in Sri Lanka, hundreds of children were separated from their parents. When several couples were claiming one baby as their own, DNA testing enabled doctors to reunite the real parents with their baby. This kind of testing is frequently used in crime-solving today.
16: DNA and Evolution
Charles Darwin's travels to the Galapagos Islands helped him understand that different species come from a common ancestor. This lecture explains the genetic components of Darwin's theories.
17: DNA and Human Evolution
Sickle cell disease is more frequently found in African Americans than in Caucasians. After studying this incurable condition, scientists discovered that carriers of sickle cell disease were resistant to malaria, a far more life-threatening sickness. Why? In this lecture, Professor Sadava explores the role of genetic adaptation in human evolution.
18: Molecular Medicine-Genetic Screening
How do scientists detect particular genes that cause certain diseases? Professor Sadava details chemical processes used for genetic screening, and gives several examples of successful genetic tests and results. He describes testing for the effects of genes on drug susceptibility as the next frontier in screening technology.
19: Molecular Medicine-The Immune System
George Washington stemmed a smallpox epidemic by ordering his soldiers to be inoculated during an outbreak. Fifty years earlier, the slave Onesimus had advised Cotton Mather, the Puritan minister, of the practice in his homeland of rubbing dried pus from a smallpox carrier onto a cut of a healthy person. This process created antibodies that resisted the disease. Professor Sadava uses these illustr...
20: Molecular Medicine-Cancer
Cancer develops when cells lose control over their normally regulated reproduction. Only 10 percent of cancers are inherited, but it is a genetic disease. This lecture explains how cancer cells are created and how they can be treated.
21: Molecular Medicine-Gene Therapy
So far gene therapy-the process of adding protein-coding DNA and a promoter sequence for its expression to an organism for medical benefit-has experienced some success in animals and small gains in humans. Professor Sadava shares cutting-edge research and experimentation.
22: Molecular Medicine-Cloning and Stem Cells
Stem cells and cloning are both controversial topics in the news. How do they really work? What is the science behind these genetic procedures, and what are their implications for us?
23: Genetics and Agriculture
Just three crops-corn, rice, and wheat-make up two-thirds of the world's food supply. Learn in this lecture how genetic experimentation on grains has resulted in significant increases in crop yields, which has meaningful ramifications for feeding the world's hungry.
24: Biotechnology and Agriculture
Changes in our environment affect the plants we grow and thus the food we eat. Biotechnology has enabled us to manipulate plants to adapt to different conditions, such as tomatoes that grow in salty soil. This final lecture explores the opportunities and controversies surrounding genetically modified plants.