Modern Genetic Research Genetics and People Modern Genetic Research

Mutations Mutation: change in DNA Mutations in body cells effect present organism, but CAN NOT BE PASSED ON to offspring Mutations in sex cells CAN be passed on to the offspring WHY?: Nonsex cells are not apart of the fertilization process—only sex cells are

Mutations Chromosomal Alterations: Nondisjunction Example: Down’s Syndrome Polyploidy Example: 3n or 4n set of chromosomes Most mutations are harmful and recessive

Genes and the environment The environment interacts with genes in the development and expression of inherited traits Here is an example…

Nature vs. Nurture In many cases it is not only the genes that we have that determine what we look like Scenario: If identical twins (same DNA) were separated at birth and lived in 2 different environments and then brought together 25 years later would they look the same? Why or why not?

Bell Ringer: March 10 If you have a mutation in your toe cells due to toxic waste. Will your offspring have a mutation as well?

Nature vs. Nurture Answer: The identical twins would have similar features (eye color, size of nose, etc.) but may look very different. What they did throughout their lives effects what they look like For example: sun exposure, diet, hygiene, injuries, etc.

Gene Expression Snowshoe Rabbit: Color of rabbit in the summertime: brown Color of rabbit in the winter: white The temperature effects what color fur (or what proteins) are expressed

Gene Expression Green color in plants: No Chlorophyll Chlorophyll Most plants have chlorophyll and the ability to be green The sun activates the protein in chlorophyll to turn plants green in color No Chlorophyll Chlorophyll

Changing Chromosome Structure Translocation: transfer of one section of a chromosome Addition: a portion of one chromosome is attached to another chromosome Deletion: a portion of a chromosome is taken away from a chromosome Inversion: a portion of a chromosome breaks off and then becomes reattached to the same chromosome in an inverted (upside down) fashion

Genetic Research Knowledge of genetics is making possible new fields of health care Mapping of genetic instructions in cells makes it possible to detect, and perhaps correct, defective genes that may lead to poor health. Substances from genetically engineered organisms may reduce the cost and side effects of replacing missing body chemicals.

Genetic Research Cloning: producing a group of genetically identical offspring from the cells of an organism This technique shows great promise in agriculture Plants with desirable qualities can be rapidly produced from the cells of a single plant

Recombinant DNA Recombinant DNA: Also called genetic engineering Creates new varieties of plants and animals by manipulating the genetic instructions of these organisms to produce new characteristics

Genetic Research Genetic Engineering: (recombinant DNA) transfer of genetic information from one organism to another includes the transfer of entire genes and gene splicing Genetic engineering can correct genetic defects & produce agriculturally more efficient plants and animals

Recombinant DNA A cell can synthesize a new chemical coded for by its new genes Examples: Interferon: helps fight infections Insulin: combat diabetes Growth hormone: help stimulate growth

Recombinant DNA X (X)

How Recombinant DNA Works Restriction Enzymes: enzymes used to cut segments of DNA in one organism so they can be transferred into another organism Characteristics produced by the segments of DNA may be expressed when these segments are inserted into new organisms such as bacteria. Inserting, deleting, or altering DNA segments can alter genes.  An altered gene may be passed on to every cell that develops from it.

Difficulties with Genetic Engineering The moved gene may not be expressed It is difficult to isolate the gene The trait may be recessive There may be unintended adverse qualities

Human Genome Project Human Genome Project: has allowed humans to know the basic framework of their genetic code Knowledge of genetics is making possible new fields of health care Genetic mapping is making it possible to detect and possibly correct, defective genes that may lead to poor health.

More on Genetic Research A down side to this is that health insurance agencies and other organizations may use this genetic information against individuals. Substances from genetically engineered organisms may reduce the cost and side effects of replacing body chemicals. Human insulin produced in bacteria is already an example of this.

Bell Ringer: March14 What is one genetic disorder and how is it detected?

Future of Genetic Engineering?

Genetic Disorder Name of Disorder Technique used to Diagnose Characteristic of Disorder Sickle Cell Anemia Microscopic examination of blood Low oxygen supply of cells Down’s Syndrome Karyotype Mental Retardation PKU Urine analysis Mental retardation

Amniocentesis One final way to check for genetic diseases is through amniocentesis Checks the proteins of the developing fetus while in the womb