Term
| plant biotechnology is the application of laboraty based techniques for which two main reasons? |
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Definition
plant propagation
or
genetic improvement |
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Term
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Definition
| the culture of plant organs, tissues, cells or protoplasts on nutrient media under sterile conditions |
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Term
| name 4 applications of plant tissue culture |
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Definition
micropropagation
suspension cultures
somatic hybridisation
production of transgenic plants |
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Term
| micropropagation. what is it important for? |
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Definition
| it is commercially important for propagating individual plant genotypes where other methods of propagation are difficult |
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Term
| cell suspension cultures involves the growth of small groups of cells in what type of growth medium? |
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Definition
liquid growth medium
these cell suspension cultures are commercially important for large scale synthesis of valuable plant products like antimicrobials, vitamins and food flavours |
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Term
| a plant cell without a wall is also known as a..... |
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Definition
protoplast.
protoplast fusion is used in somatic hybridisation to produce new hybrids between sexually imcompatible plant species |
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Term
| if i had two sexually imcompatible plant species and i wanted to create a hybrid, which application of tissue culture would i use and what method would i apply? |
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Definition
somatic hybridisation using protoplast fusion.
1. protoplasts from 2 species are mixed and induced to fuse making hybrid protoplasts
2. plants are regenerated from hybrid protoplasts by tissue culture |
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Term
| Sharong No.3 (SR3) is a salt and drought resistant wheat. what are the 2 species used to make this hybrid? |
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Definition
common wheat (Triticum aestivum)
and
Tall Wheatgrass (Agropyron elongatum) |
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Term
| most methods for making transgenic plants involve tissue culture and the regeneration of whole plants from tissue cultures. this process depends on which property possesed by many somatic plant cells? |
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Definition
Totipotency - this is the ability of an individual cell to divide and form all parts of the mature organism
totipotency depends on the capacity for dedifferentiation and redifferentiation. |
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Term
the first 2 steps invovled in plant tissue culture are
1. isolation of a small piece of plant material (explant) under sterile condtions
2. callus production on nutrient medium containing plant hormones
what is the final step. name the hormones promoting shoot and roots of plants |
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Definition
3. Organogenesis - generation of new organs from undifferentiated callus
root promoting hormone auxin
shoot promoting hormone cytokinin |
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Term
| in organogenesis whole plants are produced from an undifferentiated callus. How many stages does it take to generate a whole plant? |
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Definition
Two Stages
1. Shoot regeneration (promoted by cytokinin)
2. Rooting of shoot (promoted by auxin) |
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Term
| somatic embyrogenesis is an alternative method of plant regeneration. what does this involve and comment on the degree of ease to carry out this technique |
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Definition
this involes the development of embryos directly from differentiated or undifferentiated somatic cells
somatic embryogenesis is difficult in most species |
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Term
| what term describes the phenotypic variability between individual plants derived from plant tissue culture? |
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Definition
somaclonal variation - this is a side effect of plant tissue culture.
caused by genetic changes: aneuploidy, polyploidy, chromosome structure and DNA sequence
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Term
| give an advantage and a disadvantage of somaclonal variation |
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Definition
advantage: additional genetic variability for plant improvement
disadvantage: lack of uniformity for horticulture and forestry industries |
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Term
name the four main steps in generating transgenic plants
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Definition
- Production of DNA construct
- Transformation
- Selection via selectable marker
- Regenaration of whole plants from transformed cells
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Term
the following are four different kinds of promoters
- constitutive
- tissue-specific
- developmentally regulated
- inducible
when is a constitutive promoter expressed? |
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Definition
| it is on all the time throughout the plant |
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Term
the following are four different kinds of promoters
- constitutive
- tissue-specific
- developmentally regulated
- inducible
when is a tissue-specific promoter expressed? |
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Definition
| in a specific part of the plant for example only expressed in root hairs |
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Term
the following are four different kinds of promoters
- constitutive
- tissue-specific
- developmentally regulated
- inducible
when is a developmentally regulated promoter expressed? |
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Definition
| a developmentally regulated promoter is activated/expressed for example during fruit ripening |
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Term
the following are four different kinds of promoters
- constitutive
- tissue-specific
- developmentally regulated
- inducible
when is an inducible promoter expressed? |
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Definition
| inducible promoters are only activated when a chemical treatment is applied |
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Term
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Definition
a gene attacthed to the regulatory sequence of another gene of interest
for example cell specific promoters direct the expression of Green Fluorescent Protein (GFP) a jellyfish protein in transgenic plants |
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Term
| genes of bacterial origin that have resistant to compounds toxic to plants are known as? |
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Definition
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Term
| the E. coli gene 'nptII' has antibiotic resistance and is used as the slectable marker in some constructs for plant transformation. What specifically does this gene confer resistance to? |
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Definition
| nptII codes for neomycin phosphotransferase. This inactivates a range of aminoglycoside antibiotics such as kanamycin and neomycin |
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Term
| the herbicide resistance Streptomyces hygroscopicus bar gene is also used as a seleactable marker. which herbicide does this inactivate? |
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Definition
| phosphinothricin (glufosinate) - active ingredient of Basta™ herbicide |
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Term
getting DNA into plants can be done via two methods : Naked DNA delivery systems and Natural delivery systems.
name the 2 methods used to execute the naked DNA delivery system |
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Definition
Particle bombardment AKA Biolistics
Electroporation
Naked DNA delivery methods are suitable for dicots (tomatoes, potatoes) and monocots (cereals) |
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Term
getting DNA into plants can be done via two methods : Naked DNA delivery systems and Natural delivery systems.
in which type of plant transformation are Natural delivery systems used and which bacteria is commonly implicated? |
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Definition
Natural delivery mainly used to transform Dicots but has been used successfuly with some rice (monocot) genotypes
the bacteria commonly used is
Agrobacterium tumefaciens |
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Term
in naked dna delivery by particle bombardment what are the particles coated in?
how fast are these particles fired at the plant cell? |
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Definition
particles coated in gold
fired through a particle gun at 600m/sec
these particles penetrate cell walls and membranes - dna released and incorporated into the plant chromosomess |
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Term
| in naked DNA delivery the particles are fired at the plant callus, leaf, epidermal strips at high velocity (600m/sec) what helps to accelerate the DNA coated particles? |
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Definition
gas acceleration tube contains high pressure helium gas
OR
by electrical discharge
the target cell may be callus, whole leaves or epidermal strips |
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Term
electroporation is usually used with plant p..........s
It involves the use of a short high voltage electrical discharge making PM permeable to DNA and other polar molecules temporarily. the membrane reseas leaving the membrane intact |
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Definition
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Term
| Agrobacterium tumefaciens is a plant pathogen that produces tumours in many plant species. name the disease it typically causes in plants |
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Definition
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Term
| A tumefaciens is a natural genetic engineer because it can transfer a small segment of its DNA into the plant genome. What is the name of this section of DNA and what does it carry? |
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Definition
the section transferred is the T-DNA.
this carries genes that induce uncontrolled cell division
and
direct the synthesis of opines. - these are amino acids the bacterium can use as nutrients but the plant cannot |
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Term
| where is the T-DNA found? |
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Definition
| on the Ti plasmid (tumour-inducing plasmid) this is ~200kb |
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Term
T-DNA is bounded by ... regions called the l... and r...... borders (TL and TR)
both borders are flanked by a .....-bp direct repeat sequence
the b........ and r........ are the only sequences necessary for ............. into the plant DNA |
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Definition
two
left
right
25
borders
repeats
intergration |
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Term
| when using T-DNA to transfer genes to a plant where would we insert the genes we wish to transfer to the target plant? |
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Definition
| between the Tl and Tr borders. the regions in between these can be removed and we can insert the genes we wish to transfer to the plant |
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Term
| what is floral dipping? does this require tissue culture? |
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Definition
in this method flowers are immersed in a suspension of Agrobacterium.
This does NOT require any tissue culture
This is the method of choice for Arabidopis thaliana but not widely aplicable to other species. Transformation of germ line occurs at <0.5% |
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Term
| the generation of new organs from an explant or callus |
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Definition
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Term
| the development of embryos directly from somatic cells |
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Definition
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Term
| variability between plants derived from tissue culture |
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Definition
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Term
| name the 4 types of promoters used in DNA constructs |
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Definition
constitutive promoter
inducible promoter
tissue-specific promoter
developmentally regulated promoter |
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Term
| a type of gene used to study the activity of a promoter in transgenic plants |
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Definition
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Term
| a type of gene used to select for transformed cells or plants |
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Definition
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Term
| name two techniques used for delivering naked DNA to cells |
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Definition
| biolistics and electroporation |
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Term
| Agrobacterium tumefaciens causes? |
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Definition
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Term
| the region of the Ti plasmid that is transferred to the plant is the ? |
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Definition
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Term
| A simple method for transforming some plants without tissue culture is? |
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Definition
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