Transgenic Plants. Flashcards
Define chloroplasts?
An organelle found in plant cells that is similar to mitochondria.
Define GM foods?
Foods that have been made from transgenic plants.
Define horizontal gene transfer?
The natural sharing of genes between organisms.
Define a protoplast?
A plant or bacterial cell that has had its cell wall removed.
What is a transgenic plant?
A plant that has had its genes modified or has had a piece of foreign DNA inserted into it.
What is the popular term for foods that have been produced by genetically modified crop plants?
GM foods.
Can transgenic plants be created naturally?
Yes.
As naturally occurring horizontal gene transfer has been observed in millet and wild rice plants.
What are the 3 main reasons why scientists have created transgenic plants?
To improve the growth yields that can be obtained by plants.
To increase the nutritional value of some plants.
To offer resistance to pesticides, insects, drought and herbicides.
What are the 3 main steps involved in making a transgenic plant?
Gene manipulation.
Gene introduction.
Selection and regeneration.
What is the gene manipulation step of creating a transgenic plant?
It involves identifying and isolating a gene of interest.
Where is the gene of interest usually isolated from during the manipulation step of creating a transgenic plant?
From another plant species that exhibits the desired trait.
Or via the creation of a new allele through the modification of an existing gene.
What is the gene introduction step of creating a transgenic plant?
The introduction of the new gene into a cell that belongs to a plant that you wish to see the trait exhibited in.
How is the gene introduction step of creating a transgenic plant carried out?
Via direct DNA transfer which can be done via electroporation, microinjection or gene gun.
Or via agrobacterium mediated gene transfer.
What is agrobacterium mediated gene transfer?
Via the use of an agrobacterium which adds part of its own genome (or an edited genome) into the plant cell.
What is the selection and regeneration step of creating a transgenic plant?
It involves the use of selectable markers which inform the researcher that the cell contains the gene of interest.
The plant cell can then divide and form an adult plant.
Why will scientists use intermediate vectors to clone DNA?
So that they can have multiple copies.
How is DNA that has been created via an intermediate vector inserted into a plant cell?
The DNA is removed from the plasmid and added to an attenuated plasmid.
This plasmid can then be inserted into plant cells and the trait will be incorporated into the plant chromosomes.
What is the attenuated plasmid that DNA of interest can be inserted into?
A TI plasmid.
Where is the DNA of interest inserted into the TI plasmid?
It is added next to a selectable marker and both features as located between the T-DNA borders.
What kind of strucutre is created when the DNA of interest is inserted into the TI plasmid?
A co-integrate structure which contains the gene of interest and a selectable marker.
What are reporter genes used for?
To monitor the functions of any gene during development.
What is a common gene that is used for a reporter gene in plant transgenics?
The luciferase gene.
What organism is the luciferase gene isolated from?
From fireflies.
What enzyme does the luciferase gene produce?
Luciferase.
How does luciferase act as a report gene?
The luciferase enzyme catalyse’s a reaction between luciferin and ATP which causes light to be emitted.
How does the jellyfish green fluorescent gene act as a reporter gene?
It cause’s cells that express this gene to glow green under blue light.
How does the GUS gens (b-glucouridinase gene) act as a reporter gene?
It will turn a product called X-GLUC blue.
How does the the LAC gene act as a reporter gene?
It turns X-GAL blue.
