B12 Flashcards
What is plant biotechnology?
A method of introducing beneficial traits in plants more precisely using a variety of techniques, increasing yields and reduce harmful characteristics.
What is totipotency?
When a differentiates plant cell retains the genetic info required to generate a whole organism.
How is a plant tissue culture formed?
Piece of plant (explant) -sterile growth medium> callus -organ differentiation> root formation -plantlets generated> root and shoot formation -> micropropagation
What is in a plant tissue culture growth medium?
Solid medium of agar, sucrose as a C source, macronutrients of N, P, micronutrients, vitamins, cofactors, hormones of auxin and kinetin.
How can new plants be generated by single cells?
Micropropagation by meristem culture
How are plant protoplasts formed?
After plant cells are treated with cell wall dissolving enzymes, protoplasts can be fused to generate hybrid species with increased vigour.
What is a cell suspension culture?
Uniform suspension of cells in a liquid medium
How is a cell suspension culture made?
Plant callus -> liquid medium -> agitate continuously -> cells separate -> sub culture cells.
What are the model plants in molecular biology and genetics?
Arabadopsis thaliana (Thale cress), oryza sativa (rice).
What is Arabidopsis?
Small, weedy, member of the brassicaceae. Very small genome size, easy to germinate, short life cycle. Self-fertile, lots of mutants, low amount of repetitive DNA, susceptible to T-DNA insertions. Basic similarity to over crops.
What is T-DNA?
Transfer DNA Ti plasmid and bacteria
What is a virus?
Small infection agent can only reproduce inside living cells
What does electroporation do?
Increases permeability of cell membrane
What happens in a microinjection?
Glass pipette injects a single cell
What does a gene gun do?
DNA on precious metals, blasted into plant cells.
What is a crown gall tumour?
A crown gall is a disease caused by the bacterium Agrobacterium tumefaciens, which enters the plant through wounds in roots or stems and stimulates the plant tissues to grow in a disorganised way, producing swollen galls.
What does the Ti plasmid do in crown gall tumours?
The bacterium Agrobacterium tumefaciens, carries a plasmid called the Ti plasmid, which is tumour inducing, transduces the genetic information to plants. vir region enables infection, O is gene for opine synthesis, onc is region that specifies plant growth regulators.
How does genetic transformation with T-DNA occur?
T-DNA disarmed - once and O genes taken out, foreign gene inserted to give recombinant plasmid. Binary plasmid vector constructed and transferred into Agrobacterium, T-DNA integrated into plant genome = transgenic plant produced. Limited by species that can be infected.
What is electroporation and what does it do?
A method of introducing a substance into a cell, protoplasts in electric field take up DNA. Can be done with lots of different species but protoplast regeneration can be difficult. Increases permeability of plasma membrane cause by externally applied electric field.
How is DNA directly introduced into plants?
Gene gun, DNA on tiny gold or tungsten particles blasted into plant cells. Microinjection or virus.
What is the importance of mutants?
Important in elucidating gene function in plant biochemistry, physiology and development.
How is mutagenesis brought about?
Chemical mutagen, irradiation, insertional mutagenesis.
What are the advantages of GM Plants and agriculture?
Improved crop yield, improved nutritional value, herbicide resistance, pest resistant, grow under stressed conditions, better fruit ripening and shell life, control flowering and fruiting time
What is a GMO?
The direct human manipulation of an organisms DNA in a laboratory environment. Addition of artificial DNA. Not traditionally bred. No long term testing,
