Unit 4 Genetics : Unit 4 Genetics Ch. 13 Genetic Engineering
Selective Breeding : Selective Breeding Selective breeding - allowing animals with desired characteristics to reproduce
It takes advantage of naturally occurring genetic variation in plants, animals, etc.
Selective Breeding : 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
Selective Breeding : Selective Breeding Hybridization - crossing dissimilar individuals to bring together the best of both organisms
The organisms produced, hybrids, are usually hardier than both parents
Selective Breeding : 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
Increasing Variation : 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
Manipulating DNA : 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
The Tools of Molecular Biology : The Tools of Molecular Biology Genetic engineering - making changes in the DNA code of a living organism
The Tools of Molecular Biology : 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
The Tools of Molecular Biology : 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
Gel Electrophoresis : Gel Electrophoresis
Using the DNA Sequence : 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
Using the DNA Sequence : Using the DNA Sequence Making copies:
Polymerase chain reaction (PCR) - technique that allows biologists to make many copies of a particular gene
Cell Transformation : 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
Transforming Bacteria : Transforming Bacteria Plasmid - circular DNA of bacteria
Applications of Genetic Engineering : 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
Transgenic Organisms : 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
Transgenic Organisms : 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
Transgenic Organisms : 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
Cloning : Cloning Clone - a member of a population of genetically identical cells produced from a single cell
Cloning : Cloning