dna technology chapter 13 honors biology genetically modified organisms modified genome of an...
Post on 18-Dec-2015
218 Views
Preview:
TRANSCRIPT
Genetically Modified Organisms•Modified genome of an organism
▫Takes DNA from multiple sources and combine them to form a new genome DNA from same species DNA from different species- Transgenic
organisms
Crops that
•Do NOT need fertilizer
•Disease resistant plants
•Insect resistance
•Herbicide resistant
•Salt-tolerant plants
Golden Rice• Insertion of
genes to produce a precursor of vitamin A (beta-carotene)
• Helps areas where there is a shortage of dietary vitamin A Golden
riceWhite rice
Dangers of GMO’s
•Unexpected allergies
•Introduction of new genes to a population▫SUPER
WEEDS•Creation of
invasive species
DNA Fingerprints
•I. DNA Fingerprints pattern of bands made up of specific fragments from an individual’s DNA
•USED FOR:▫DETECTION OF A RELATIVE▫SIMILARITIES BETWEEN SPECIES
▫Forensics
Forensics- DNA fingerprinting
•VNTR- Variable number
tandem repeats
•Show variations in length
between individuals
•Can be compared with
DNA databases (CODIS)
What about twins?
•Dizygotic (fraternal twins) do not have the
same DNA
▫More like siblings that happen to be the
same age
•Monozygotic (identical twins)have identical
DNA
▫But not identical fingerprints!
How do you make DNA fingerprints?
•RFLP (restriction fragment length polymorphism) analysis▫1. extract DNA from specimen using
restriction enzymes▫2. separate fragments of DNA using
electrophoresis (separates DNA according to size and charge)
▫3. placed in wells made on gel and run electric current through gel
▫4. blotted onto filter paper/ photgraphic film.
Analysis▫negative fragments migrate to positive charged end of gel but not all at same rate
▫pores in gel allow smaller fragments to migrate faster separating fragments by size.
• Electrophoresis “electro” = electricity “phoros” = to carry across
• Determine the genetic differences and the
evolutionary relationship among species of
organisms
• Method that separates on basis of size, electric
charge and other physical properties
Accuracy of DNA Fingerprints•DNA fingerprints are very accurate
•However, genetic tests can only absolutely disprove, not prove, relationship!
•Courts accept 99.5% accuracy as proof of alleged paternity
Polymerase Chain Reaction (PCR)
•Used when you only have a TINY piece of DNA
•PCR can be used to quickly make many copies of selected segments of the available DNA
•Use a PRIMER to initiate replication
•DNA doubles every 5 minutes
PCR is used for:•1. Forensics▫increased the amount of DNA evidence for testing
•2. Diagnosing genetic disorders
•3. Studying ancient fragments of DNA (tiny amounts)
Vaccines•Used to improve
immunity against certain diseases
•Present- Uses weakened or dead versions of the microorganism▫Risk of the body not
being able to handle the infection
▫Risk of dead organisms reviving
DNA Vaccines
•Future- DNA vaccines- using specific parts of DNA that code for antigens ▫No risk of infection
Avian flu- virus
Cloning
• Growing a population of genetically identical cells from a single cell.
• 1997 - Ian Wilmut with Dolly, the cloned sheep
• CLONE• 1. A cell, group of
cells, or organism from and genetically identical to a single ancestor.
• 2. An organism descended asexually from a single ancestor.
• CLONING• 1. To make multiple
identical copies of a DNA sequence.
• 2. To create or propagate an organism from a clone cell.
• 3. To produce a copy of.
Clone vs. Cloning
Uses• Cloning can be used to test for
genetic diseases
• Regenerate nerves or spinal cord
tissue
• Help in plastic surgery
• Clone organs for transplantation
• Grow skin grafts for burn victims
• Manufacture bone, fat, and
cartilage
Steps
1. Remove nucleus from egg cell
2. Fuse de-nucleated cell with a body
cell from another adult
3. Cells fuse to become 2N and then
divides
4. Implant embryo in reproductive
system of foster mother
Ethical Issues
What are the implications of cloning?How will cloning affect the medical field?
What will be the effect on the gene pool?
Is there potential for abuse?How should it be regulated?Would you consider cloning yourself?
Stem Cells
•Self renewing-regenerate•Multi-potency- can become many different
types of cells
•Uses▫Basic Knowledge of Human Development▫Models of Human Disease▫Transplantation-Cell Replacement ▫Drug Development ▫Organogenesis
top related