Shared Flashcard Set

Details

Bio 114 Lecture 8
Plant Biotechnology II
36
Biology
Undergraduate 1
03/08/2013

Additional Biology Flashcards

 


 

Cards

Term
what are characteristics such as yield, herbicide tolerance, disease and pesticide resisitance, tolerence to drought, heat, cold , salinity and reproduction collectively known as?
Definition
Agronomic traits
Term

True or False?

Proceesing, shelf-life, nutritional quality and reduced anti-nutritional characteristics are known as QUALITY TRAITS

Definition
This is true yo!
Term
name some novel crop products that are tragets of plant biotechnology
Definition

oils

proteins: parmaceuticals, vaccines

polymers, plastics

Term
what are the two traits that account for the majority of the GM crops under cultivation?
Definition

Herbicide tolerance (HT) glyphosate resistance

and

Insect resistance (Bt)

 

soyabean, maize and cotton are the 3 main GM species

Term
Glyphosate (Roundup® ) is made by Monsanto since the 1970's. What type of herbicide is it?
Definition

A broad-spectrum herbicide

 

it works by inhibiting a choloroplast enzyme (EPSP synthase) required for aromatic amino acide synthesis

Term
what is the shkG?
Definition
it is a mutant EPSP synthase gene isolated from a bacterium resistant to the herbicide. this gene was introduced into plants to confer glyphossate resistance - a simple monogenic trait
Term
name the pro of HT crops
Definition

advantages - enhances crop productivity

< soil erosion

< fuel costs and greenhouse emissions

encourages a 'no-till' agriculture

Term
list some cons of HT crops
Definition

increased use of Roundup® but reduced use of other herbicides

 

possible reduction in biodiversity?

Term
which soil bacterium has spores that contain a crystalline protein that kills by binding to receptors in the gut of the target insect?
Definition

Bacillus thuringiensis (Bt)

 

the spores were first used commercially in 1938 and still used by organic farmers. very specific so not toxic to other animals and environmentally friendly

Term

here are the first few steps in how Bacillus thuringiensis kills larva.

1. lava consumes toxin

2. crystals solubilised and toxin activated by proteolytic cleavage in mid gut

3.toxin binds to specific receptors

 

describe the final 2 steps

Definition

4. binding triggers cell death in mid-gut lining

 

5. septicaemia follows and larva dies

Term

True or False?

different cry genes target different groups of insects

Definition

true

 

eg cry1Ab kills Lepidoptera

one of the most common Bt maize varieties (MON810) carries the cry1Ab gene which confers resistance against European stem borer

Term
the European Corn Borer is a major pest of the maize in the USA. how much loss does it cost per year?
Definition
1.5 billion kg/year in maize production in USA
Term
list pros of Bt crops
Definition
  • reduced financial costs due to less pesticide use
  • reduced environmental impact of chemical pesticides
  • improved health of farmers
  • improved food quality due to reduction in fungal toxins
Term
list cons of Bt crops
Definition

selection pressure for resistant pests

 

possible effect on non-target insects (controversial)

Term
what does cspB stand for and what does it do?
Definition

cspB = cold shock protein from Bacillus subtillis

 

it belongs to a class of RNA-binding proteins known as RNA chaperones that stabilise mRNA.

when over expressed in a variety of plant species it confers increased tolerence to drought, heat, cold and stress

Term
which protein does the MON87460 GM maize express?
Definition

cspB - it was approved for release in the US in late 2011

 

MON87460 shows reduced yield loss relative to conventional corn under water-limiting conditions

Term
what is golden rice enriched with?
Definition
provitamin A
Term

what is vitamin A?

where do humans obtain their Vitamin A from?

Definition

vitamin A (retinol) is a pigment of the eye and the acid retinoic acid is a growth hormone

 

humans get vit A from plants (B carotene) in the form of provitamin A. this gets converted into Vit A in intestine and liver

animal products containing vitamin A eg, milk, liver and eggs 

Term
list symptom(s) of Vitamin A Deficiencey (VAD)
Definition

night-blindness, xerophthalmia (dry eyes)

 

VAD is associated with increased susceptbility to death from childhood diseases

Term
describe the epidimeology of VAD
Definition

severe public health problem in developing countries

124 million children worldwide suffer from VAD

1 to 2.5 million childhood deaths annualy

 

vit A tablets are effective but expensive and difficult to administer in developing countries on a large scale

Term
what is the main cause of VAD?
Definition

the low vitamin A content in rice. it is the staple diet for over 2billion of the 6billion people in the world

 

polished rice contains little or no B carotene

Term
how many enzyme catalysed steps are there in the biosynthesis of B-carotene?
Definition

Geranyl geranyl pyrophosphate (GGPP) 

(phytoene synthase)

Phytoene

(phytoene desaturase)

zeta-carotene

(zeta carotene desaturase)

Lycopene

(lycopene cyclase)

B-carotene baby!

Term
in golden rice version one (GR1) where was the genes taken from to synthesise Phytoene synthase?
Definition

Daffodils - this gave 1.6 ug B-carotene/g

 

A second version GR2 has higher levels of B carotene. This was made using Phytoene synthase from maize giving 37ug B carotene/g

Term

True or False?

there will be no fee for the humanitarian use of Golden rice and farmers will be permitted to keep and replant the seed

Definition

True. As long as the farmer makes <$10,000 per year from its use.

Golden rice is incorporated into rice breeding programs in Philippines, India, Bangladesh, China and Vietnam

 

GR2 contains enough B- carotene in 72g dry rice to provide 50% of a childs RDA of Vitamin A

Term
what name is given to vaccines where the antigen is produced in a transgenic plant and can be administered orally?
Definition

Edible vaccines

advantages of this are:

  • production highly efficient and can be scaled up
  • no refrigeration required, can be stored near site of use and no needles required
  • appropiate for developing countries where production storage and transport is difficult
Term

list the rest of the steps in developing an edible vaccine for measles (MV)

 

1. select an antigen

2. isolate the MV-H gene (measles virus haemagglutinin)

3. express the MV-H gene in edible transgenic plant eg. lettuce

Definition

 

4. test effectiveness by feeding MV-H lettuce to mice

5. Assay for the presence of anti MV-H antibodies in the mice

Term

true or false?

edible vaccine expression in plants has been demonstrated for antigens against cholera, rabies, norwalk virus and hep B

Definition

true - also an edible vaccine conferring dual immunity against cholera and malaria has recently been reported

 

at least 3 human trials have shown potential effectiveness of edible vaccines

Term
name a gene that enhances drought tolerance in maize
Definition
cspB (cold, shock protein B)
Term
name a gene that confers resistance against European stem borer
Definition
cry1Ab
Term
name a gene that confers glyphosate resistance
Definition
shkG
Term
what is another name for glyphosate?
Definition
Roundup® Ready
Term
Bt toxin exists in ....................... form inside the bacterial spore
Definition
crystalline
Term
name a major insect pest of corn in the USA
Definition
European Corn Borer
Term
what is another name for provitamin A?
Definition
B-carotene
Term
name 2 symptoms of vitamin A deficiency
Definition

Night blindness

Dry eyes

Term
name the antigen used to create an edible vaccine against measles
Definition
MV-H measles vaccine haemagglutinin
Supporting users have an ad free experience!