Term
| What are some of the disadvantages of breeding plants for agriculture? |
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Definition
No control over gene transfer
Need to produce 1000s of hybrids
Progeny with many undesirable traits
Need backcrossing with parents
VERY SLOW (but it works)
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Term
| What is the yield plateau? |
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Definition
| Product of green revolution, 1 percent increase in wheat yield today is considered 'good' |
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Term
| What can not be done by classic breeding? What do you need to do these things? |
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Definition
Make hybrids between unrelated plants
Introduce single genes into species
Delete or down-regulate existing genes
These things require molecular biotechnology |
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Term
| What is a plant tissue culture and what are some types? |
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Definition
A culture of plant cells, tissues or organs under aseptic conditions which are totipotent (unlignified nucleated cells, meristematic or parenchyma cells)
Callus: Mass of undifferentiated cells
Cell suspensions: individual cells
Organ/plant culture: whole or part plants |
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Term
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Definition
| A plant cell lacking the cell wall |
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Term
| What determines the type of development in a callus? |
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Definition
| Auxin (callus formation/root initiation) / cytokinin (shoot initiation) ratio |
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Term
| What is the general sequence for micropropagation? |
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Definition
Generate shoots in culture
Induce multiple shoots with cytokinin
Divide into many pieces and repeat
Induce roots with auxin
Transfer to soil |
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Term
| Why does cloning plants eliminate viruses? |
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Definition
| Because meristematic cells divide faster than viruses can move through plant, so they never have viruses in them |
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Term
| When plants regenerated from the same callus aren't identical genetic clones, what is this? What drives this process |
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Definition
| Somaclonal variation, change is epigenetic |
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Term
| How would you go about selecting herbicide tolerant mutants through a callus culture? |
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Definition
Obtain cell suspension
Culture for a long time
Spread onto agar medium containing herbicide
Select tolerant calli
Regenerate plant from tolerant callus |
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