Genetic Techniques Flashcards
What is selective breeding
To select individuals with the characteristics you want and breed them together
Main steps involved in selective breeding
1) decide which characteristics are important enough to select
2) choose parents that show these characteristics from a mixed population
3) choose the best offspring with the desired characteristics to produce the next generation
4) repeat the process continuously over many generations
Potential benefits (plants) selective breeding:
- higher crop yield
- resistance to certain diseases
- resistance to certain insect pests
- hardier - surviving in harsher climates or are productive for more of the year
- better balance of nutrients in crop
Potential benefits (animals) selective breeding:
- higher yield of meat, Milk or eggs
- fur - higher yield and better quality
- increased number of offspring
- increased resistance to disease
- hardier
Definition of genetic engineering
The transfer of DNA from one organism to another using biotechnology
Why are organisms genetically modified
In order to give them a combination of genes (genotype) that will result in them having desirable physical characteristics (phenotype)
Name two types of enzymes that are used to cut out genes from one molecule of DNA and stick them back into another
Restriction endonuclease
Ligase
Method of transferring a gene from any cell into a bacterium
Insert the gene into a plasmid and then transfer the plasmid into the bacterium
The plasmid is called a vector because it is the means of transferring the gene
What is another vector used to to introduce foreign DNA into bacterial cells
Bacteriophage - a virus that attacks a bacterium
How does a bacteriophage attack a bacterium
Attaching to the cell wall of the bacterium and injecting into own DNA into the bacterial cell
This DNA becomes incorporated into the DBA of the host cell and eventually causes the production of many virus particles
Different bacteria have been genetically modified to manufacture a range of products
1) human insulin
2) enzymes for washing powder
3) enzymes for food industry
4) human growth hormone
5) bovine somatotrophin
6) human vaccines
Manufacture of insulin:
Restriction enzyme is used to cut out insulin gene from human DNA
Restriction enzyme is used to cut open plasmid DNA of bacteria
Insulin gene is inserted into plasmid DNA of bacteria and is joined together using ligase enzyme
Insulin gene is new recombinant and inserted into bacterial cell
Transgenic bacteria is complete and is grown in a fermenter to reproduce and duplicate
Name the two main stages of the procedure of genetically modifying plants
1) introducing the new gene or genes into plant cells
2) producing whole planet from jsut a few cells
Uses - plants GM
- extended shelf life
- resistance to herbicide
- human antibody production
Future aims - plants GM
Resistance to pests and pathogens
Heat and drought tolerance
Salt tolerance
Advantages of GM animals
- manufacture of human proteins such as antibiotics etc
- increased production of a particular product
- higher resistance to disease
- production of organs for transplantation
What is xenotransplantation
Transplanting organs from other animals into humans
Process of GM animals
DOnor cell taken from sheep’s udder
Egg cell taken from female sheep - nucleus of egg removed
These 2 cells are fused using an electric shock
The fused cell begins dividing normally
The embryo is placed in uterus of a foster mother
Embryo develops normally into a lamb
Transgenic meaning
The transfer of genetic material from one species into a different species
Give two advantages of using organs produced by therapeutic cloning compared to using donated organs
No need to match
No shortage of organs
Free from disease
What is micropropagation
The process in which very small pieces of plants (tissue) are grown using nutrient media
Advantages of micropropagation
Rapid production of large numbers of genetically identical plants
Reproduction of plants that do not grow well from seeds or cuttings
Convenient storage of many small plants in early stages of development
How to propagate plants in vitro
Cells scraped from the parent plants
Cells are transferred to a sterile Peter dish contains nutrient Agar
Hormones are added to encourage plants to grow into small masses of tissue
Tissues continue to grow and forms plántelos that can be transferred to individual potting trays and develop into plants
Commercial uses of micropropagation
Allows a variety of a plant with desirable characteristics to be produced:
- cheaply
- with greater yield quickly
- at any time of year
