Food Security (6) Flashcards
The world needs to produce at least 50% more food to feed an estimated 9 billion people by 2050. However:
- climate change could cut crop yields by more than 25%.
- land available for crop production is limited, with much of the world’s best soils already in use and others protected, for example, for environmental concerns. The demand for food brings marginal lands into play for which stress-tolerant crops need to be developed.
“Unless we change how we grow our crops food security—especially for the world’s poorest—will be at risk.” How can we do this?
To help do this plant breeders can use asexual/vegetative propagation (somemethods were mentioned earlier) and genetic engineering techniques. Breeders often combine both of these methods.
International development agencies believe that breeding new crop varieties is extremely important for ensuring food security. The new varieties need to be: (4)
- even higher-yielding than at present.
- resistant to pests and diseases.
- drought-resistant or regionally adapted to different environments and growing conditions.
- able to use soil nutrients more efficiently.
How could asexual reproduction benefit future crop production? (5)
- Propagation is faster than from seed because there is no gamete formation, pollination, etc.
- All the propagated plants are of a consistent superior quality.
- Large quantities of plants can be produced cheaply, easily and quickly, eg by cuttings. perennating organs, eg bulbs (onions) and tubers (potatoes). • Using the grafting technique fruit trees will grow more quickly to maturity and thus to fruit production, eg avocado pears.
- By micro-propagation (tissue culture) numerous new identical plants (clones) are produced.
Micro-propagation is favoured over traditional crop breeding methods as (4)
- commercially important crop plants can be mass propagated in a very short period of time, eg bananas, pineapples, potatoes, date and oil palms, papaya.
- disease-free plants can be produced by selecting disease-free cells and culturing them in sterile conditions.
- propagation can take place all year independent of seasonal changes.
- it may be used together with genetic engineering to propagate transgenic plants from genetically modified cells
What is tissue culture or micropropagation?
Tissue culture or micropropagation = a processwhereby a small amount of plant tissue is cultured in a growing medium to produce a callus and then plantlets
What is a callus?
a shapeless clump of cells
What is genetic engineering?
Genetic engineering is the process of takinga gene out of one organism and put it into the DNA of another organism.
What are the resulting plants that comes as a result of genetic engineering?
The resulting plants are known as genetically modified organisms (GMOs, GM crops, or biotech crops) and the gene that has been transplanted is a transgene.
What is the benefit of genetic engineering?
The production of a new variety with a desired trait in this way is achieved in a much shorter time compared to conventional breeding.
There are no real interspecies barriers in this type of crop production: all organisms use the same ____ ___ , so genes from bacteria, for example, will produce the correct protein in a maize plant.
genetic code
A few examples of GMOs:
• Bt maize. Bacillus thuringiensis, a soil bacterium, produces a protein that kills many insect pests, especially the maize earworm. The gene for this protein has been transplanted into much of the USA’s maize crop giving the maize crop _____ to that pest.
• Roundup Ready soybeans (plus other crops). Roundup is a brand name for a herbicide called glyphosate. A bacterial gene that confers ____ to this herbicide has been transplanted to many crops. The farmer can then spray the fields with glyphosate and kill virtually all the weeds without harming the crop. About 87% of the USA’s soybean crop now contains this gene.
resistance
resistance
What is a herbicide?
a chemical that kills herbs/weeds
What traits are biotechnologists trying to incorporate into food crop plants? (7)
- resistance against certain diseases and herbicides
- increased tolerance to insect pests.
- nutrient-content enrichment
- increased tolerance of environmental pressures
- flood tolerance
- longer storage life of harvested crops
- improved flavour
It is obvious that combining ____ agricultural practices with modern biotechnology can enable the achievement of food security for present and future generations. However, it is important that the performance of a GM crop is closely studied for several generations and goes through rigorous ___-_____ assessments, before being released for commercial cultivation. GM crops are going to be an essential part of our life and the enormous potential of biotechnology must be used to the benefit of humankind.
conventional
bio-safety
