1 DNA Technology

2 DNA Extraction Chemical treatmentsChemical treatments cause cells and nuclei to burst stickyThe DNA is inherently sticky, and can be pulled out of the mixture “spooling”This is called “spooling” DNA

3 “Spooled” DNA

4 Cutting DNA Restriction enzymesRestriction enzymes cut DNA at specific sequences manageable fragmentsUseful to divide DNA into manageable fragments

5 Electrophoresis size and chargeDNA can be separated based on size and charge phosphate groupsnegativelyThe phosphate groups are negatively charged gelelectricityDNA is placed in a gel and electricity is run through

6 Electrophoresis Negative DNANegative DNA moves toward the positive end Smaller farther and fasterSmaller fragments move farther and faster

7 Electrophoresis

8 Steps in DNA Sequencing Many copies of a single strand of DNA are placed in a test tubeMany copies of a single strand of DNA are placed in a test tube DNA polymerase is addedDNA polymerase is added A mixture of nucleotides is added some of which have dye molecules attachedA mixture of nucleotides is added some of which have dye molecules attached Each base (A,T,C,G) has a different color dyeEach base (A,T,C,G) has a different color dye

9 Steps in DNA Sequencing some dyed nucleotidessome regular onesBy chance, some dyed nucleotides & some regular ones are added stop the chainDye molecules are large and stop the chain from growing

10 DNA Sequencing multiple sizes with colors that can be identifiedThe result is DNA fragments of multiple sizes with colors that can be identified

11 DNA Sequencing After the gel separates the resulting fragments by size, we 'read' the sequence from bottom to top.After the gel separates the resulting fragments by size, we 'read' the sequence from bottom to top.

12 Copying DNA Polymerase Chain ReactionPolymerase Chain Reaction Also called PCR A method of making many copies of a piece of DNA

13 Steps in Copying DNA A DNA molecule is placed in a small test tube DNA polymeraseDNA polymerase that can work at high temps is added

14 Steps in Copying DNA DNA is heatedThe DNA is heated to separate the two strands PrimersPrimers, short pieces of DNA complementary to the ends of the molecule to be copied, are added

15 Copying DNA DNA polymerase adds new bases to the separated strandsThe tube is cooled, and DNA polymerase adds new bases to the separated strands

16 PCR Large amounts of DNA can be made from a small starting sample

17 Selective Breeding Selective breeding allows only those organisms with desired characteristics to produce the next generation. Nearly all domestic animals and most crop plants have been produced by selective breeding. –Humans use selective breeding to pass desired traits on to the next generation of organisms.

18 Hybridization is the crossing of dissimilar individuals to bring together the best of both organisms. Inbreeding is the continued breeding of individuals with similar characteristics. Inbreeding helps to ensure that the characteristics that make each breed unique will be preserved. Serious genetic problems can result from excessive inbreeding.

19 Breeders increase the genetic variation in a population by inducing mutations. Mutations occur spontaneously, but breeders can increase the mutation rate by using radiation and chemicals. Breeders can often produce a few mutants with desirable characteristics that are not found in the original population.

20 –Producing New Kinds of Plants Mutations in some plant cells produce cells that have double or triple the normal number of chromosomes. This condition, known as polyploidy, produces new species of plants that are often larger and stronger than their diploid relatives. Polyploidy in animals is usually fatal.

21 Scientists use different techniques to: extract DNA from cells cut DNA into smaller pieces identify the sequence of bases in a DNA molecule make unlimited copies of DNA In genetic engineering, biologists make changes in the DNA code of a living organism.

Cell Transformation Recombinant DNA Host Cell DNA Target gene Modified Host Cell DNA

23 –During transformation, a cell takes in DNA from outside the cell. The external DNA becomes a component of the cell's DNA. –If transformation is successful, the recombinant DNA is integrated into one of the chromosomes of the cell.

24 –Transgenic Organisms An organism described as transgenic, contains genes from other species. –Genetic engineering has spurred the growth of biotechnology. Transgenic Microorganisms Transgenic bacteria produce important substances useful for health and industry. Transgenic bacteria have been used to produce: insulin growth hormone clotting factor

25 –Transgenic Animals Transgenic animals have been used to study genes and to improve the food supply. Mice have been produced with human genes that make their immune systems act similarly to those of humans. This allows scientists to study the effects of diseases on the human immune system.

26 Researchers are trying to produce transgenic chickens that will be resistant to the bacterial infections that can cause food poisoning. –Transgenic Plants Transgenic plants are now an important part of our food supply. Many of these plants contain a gene that produces a natural insecticide, so plants don’t have to be sprayed with pesticides.

27 Cloning CloneClone- a member of a group of genetically identical cells asexual reproductionMay be produced by asexual reproduction (mitosis)

28 Cloning organisms body cell egg cellA body cell from one organism and an egg cell from another are fused divides like a normal embryoThe resulting cell divides like a normal embryo

29 Cloning “Dolly”

30 Human Genome Project

31 Human Genome Project Started in 1990 Research effort to sequence all of our DNA (46 chromosomes) Over 3.3 billion nucleotides Mapping every gene location (loci) Conducted by scientists around the world

32 HGP Insights Only 2% of human genome codes for proteins (exons) Other 98% (introns) are non-coding Only about 20,000 to 25,000 genes (expected 100,000) Proteome – organism’s complete set of proteins About 8 million single nucleotide polymorphisms (SNP) – places where humans differ by a single nucleotide About ½ of genome comes from transposons (pieces of DNA that move to different locations on chromosomes)

33 Benefits of Human Genome Project Improvements in medical prevention of disease, gene therapies, diagnosis techniques …Improvements in medical prevention of disease, gene therapies, diagnosis techniques … Production of useful protein products for use in medicine, agriculture, bioremediation and pharmaceutical industries.Production of useful protein products for use in medicine, agriculture, bioremediation and pharmaceutical industries. Improved bioinformatics – using computers to help in DNA sequencing …Improved bioinformatics – using computers to help in DNA sequencing …

34 Benefits of Genetic Engineering

35 Biotechnology - The use of gene science to create new products from plants and animals

36 Biotechnology Provides: Improved food products Medical advances An enhanced environment Improved food products Medical advances An enhanced environment

37 Herbicide Resistant Crops Soybeans: Roundup Ready Corn: Roundup Ready, Liberty Link Cotton: BXN, Roundup Ready Canola: Liberty Link, Roundup Ready + CP4 EPSPS = Roundup gene Ready

38 Biotechnology Breakthroughs Insulin (1982) –First commercial biotech product –Reliable, inexpensive source of insulin Rice –Enriched with beta-carotene and iron Bananas –Containing edible hepatitis vaccine Insulin (1982) –First commercial biotech product –Reliable, inexpensive source of insulin Rice –Enriched with beta-carotene and iron Bananas –Containing edible hepatitis vaccine

39 Biotechnology Breakthroughs Potatoes with higher solid content Garlic that lowers cholesterol Fruits and vegetables that reducerisks of cancer and heart disease Potatoes with higher solid content Garlic that lowers cholesterol Fruits and vegetables that reducerisks of cancer and heart disease

40 Environmental Benefits Reduced pesticide use Lower energy requirements Cleaner water Less soil erosion Reduced pesticide use Lower energy requirements Cleaner water Less soil erosion

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