- Basic Concepts
- DNA & RNA
- Simple Inheritance
- Modify Mendelian Ratios
A genome is the total amount of genetic material in a cell. In eukaryotes, it is the haploid set of chromosomes of an organism. Genomes consist of DNA molecules that are made up of long and varying sequences of adenine (A), thiamine (T), guanine (G), and cytosine (C). These DNA molecules compose the genes that code for all of the proteins that are made by an individual.
In 1990 the Center of Human Genome Research (a department of the National Institutes of Health) and the U.S. Department of Energy initiated the Human Genome Project. The goal of the project was to determine the sequence of the 3-billion nucleotide pairs and the location of the genes in the human genome. The sequence of the entire genome was sought because it would be a very useful tool in medicine. Since the genome contains all of the genetic information, it contains the sequences for all of the genes that cause cancer, Parkinson's disease, and other genetic diseases. By finding the location of these genes and their sequences, scientists can find the proteins that they code for and gain an understanding for how the proteins work. This knowledge will enable scientists and doctors to create the necessary drugs or methods of treatment in order to combat the diseases.
In February 2001, scientists reached their goal, and it was announced that a rough draft of the human genome sequence had been completed. Of course, the next part of the project, making sense of all of that sequence, is an active area of current research.
Sequencing the genomes of other animals and microorganisms is also a very important research topic. The genomes of a fruit fly (D. melanogaster), a worm (C. elegans), a plant (A. thaliana), a yeast (S. cerevisiae), and several bacteria had been sequenced by the time this site was developed, and scientists were working on those of the laboratory mouse and many other species. In fact, by the time you read this page, many of these projects will probably be finished. By comparing areas of the human genome to comparable areas in the genomes of these simpler and more manageable animals, scientists can gain a better understanding of how certain proteins work and apply that understanding to human medicine. Of course, the lessons learned from the human genome project will also be applied to enhance the understanding of nonhuman organisms that have agricultural, environmental, and medical importance.