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Ch. 13 Genetic Engineering

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1 Ch. 13 Genetic Engineering
Unit 4 Genetics Ch. 13 Genetic Engineering

2 Selective Breeding Selective breeding - allowing animals with desired characteristics to reproduce It takes advantage of naturally occurring genetic variation in plants, animals, etc.

3 Selective Breeding Humans use selective breeding to pass desired traits on to the next generation of organisms Nearly all domestic animals (horses, cats, etc.) & most crop plants have been produced by selective breeding

4  Selective Breeding Hybridization - crossing dissimilar individuals to bring together the best of both organisms The organisms produced, hybrids, are usually hardier than both parents

5 Selective Breeding Inbreeding - continued breeding of individuals with similar characteristics Many breeds of dogs are maintained by inbreeding It helps to ensure the characteristics of each breed are preserved

6 Increasing Variation Selective breeding can increase genetic variation in a population by causing mutations to occur SB was used to create oil-eating bacteria, used to clean up oil spills

7 Manipulating DNA Scientists study & change DNA molecules
Different techniques are used to extract (remove) DNA from cells, to cut DNA into smaller pieces, to identify the sequence of bases in a DNA molecule, & to make unlimited copies of DNA

8 The Tools of Molecular Biology
Genetic engineering - making changes in the DNA code of a living organism

9 The Tools of Molecular Biology
Cutting DNA: DNA molecules are too large to be analyzed, so biologists cut them precisely into smaller fragments Restriction enzymes enzymes that cut DNA at a specific sequence of nucleotides

10 The Tools of Molecular Biology
Separating DNA: Gel electrophoresis - a mixture of DNA fragments is placed at 1 end of a gel, & an electric voltage is applied to the gel When the power is turned on, DNA fragments move toward the + end of the gel Smaller DNA fragments move faster & farther

11 Gel Electrophoresis

12 Using the DNA Sequence Cutting & pasting: DNA sequences can be changed
Restriction enzymes - used to take a gene from 1 organism & attach it to the DNA of another organism Recombinant DNA - DNA molecules produced by combining DNA from different sources

13 Using the DNA Sequence Making copies:
Polymerase chain reaction (PCR) - technique that allows biologists to make many copies of a particular gene

14 Cell Transformation During transformation, a cell takes in DNA from the outside (DNA from another organism) That external DNA combines with the cell’s DNA As the cell copies its own DNA, it also copies the external DNA, since the 2 were combined during transformation

15 Transforming Bacteria
Plasmid - circular DNA of bacteria

16 Applications of Genetic Engineering
Genetic engineering makes it possible to transfer DNA sequences, including whole genes, from 1 organism to another It has spurred the growth of biotechnology, a new industry that is changing the way we interact with the living world

17 Transgenic Organisms Transgenic - organisms have genes from other species A gene from 1 organism can be inserted into cells from another organism Those transformed cells can be used to grow new organisms

18 Transgenic Organisms Transgenic Animals:
They have been used to study genes & improve the food supply Mice have been produced with human genes that make their immune systems similar to ours Livestock have extra copies of human growth hormone

19 Transgenic Organisms Transgenic Plants:
Many crop plants contain genes that produce a natural insecticide Others have genes that allow them to resist weed-killing chemicals Rice has been genetically modified to contain Vitamin A, essential for human health

20 Cloning Clone - a member of a population of genetically identical cells produced from a single cell

21 Cloning

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