Lectures 1-3 (sgriculture)

Question 1

Give t3o examples of how past climate change altered crop production

Answer 1

1. The great famine (1315-1317) occurred following the little ice age, where the seed return from wheat went from 7:1 to 2:1 following a volcanic eruption
2. The Irish potato famine. Potato blights cause widespread crop loss and famine

Question 2

What are there three current main threats to food production?

Answer 2

1. Soil salinity and erosion
2. Climate change (and associated impacts such as changing rainfall patterns)
3. Lack of incentive for rural careers (decreasing the amount of people available to produce food)

Question 3

What are the three methods of attempting to address climate changes impact on future food production?

Answer 3

1. Conduct experimental trials
2. Look at historical yield patterns to correlate past climate change to current/ future
3. Predictive yield modelling

Question 4

What is predictive yield modelling and what are the draw backs?

Answer 4

Utilising experimental trials and past environmental yield evidence to predict future changes to yields in response to changing climates. The key limitation to this study doesn’t take into account how plants may adapt to climate change or agronomy practices

Question 5

What are the limitations of conducting experimental trials on plant response to climate change?

Answer 5

1. The environmental conditions are unreliable ( eg. Temperatures are not constant throughout the day)
2. Rainfall is often poorly simulated
3. Not all climate change impacts are taken into account

Question 6

Why do plants have to be closely related in plant breeding?

Answer 6

To avoid hybrid sterilisation

Question 7

What are the three main advantages of plant breeding?

Answer 7

1. It’s free, requiring limited plant knowledge
2. It’s socially acceptable
3. Limited technology required

Question 8

What are the disadvantages of selective plant breeding?

Answer 8

1. Time consuming
2. Labour intensive
3. Difficult to modify the transfer of genes, and achieving the desired result may time time because of this
4. High genetic uniformity of plants increased the risk to yields from pathogens etc.

Question 9

How does plant selection occur

Answer 9

When wild species with not eagle desirable properties are noted, they are cross bred with domestic varieties (that are closely related). This new species is called the progeny of F1 hybrid. This process occurs over several generations with BACKCROSSING to ensure that the preferred gene remains in plants. BACKCROSSING continuities until offspring resembles the domestic plants preferable agricultural attributes and the desired trait from the wild plant.

Question 10

What are F1 hybrids and how are they evaluated?

Answer 10

They are the first generation of plants produced in plant breeding. They are assessed via PHENOTYPE SELECTION, a process checking desired traits have been passed onto offspring

Question 11

What are the two methods of plant selection?

Answer 11

1. Cross pollination of plants from a SINGULAR species

2. Hybridisation of two distance species, within the same genome

Question 12

Which country used to grow gym crops, but now banns them?

Answer 12

China

Question 13

Which is the only EU country that contains gm cops?

Answer 13

Spain

Question 14

What are the two qualities of first generation gm crops?

Answer 14

Herbicide and pesticide resistance. Some have stacked traits, meaning containing both

Question 15

How does herbicide gm work?

Answer 15

The specific gene is the amino acids of agrobscterium cp4 is resistant to GLYHOSATE( key chemical used in herbicides)

Question 16

What herbicide are gm crops made resistant to?

Answer 16

Glyphosate

Question 17

How does insect resistance gm work?

Answer 17

The bt bacteria produce dry proteins which are inserted into lungs. These genes are toxic in insect guts, but have no impact on humans

Question 18

What is the most common promoter in gm crops?why?

Answer 18

The 35s viral promoter, as it allows the gene of interest to be expressed in itch quantities through the plant.

Question 19

What is the key difference between first and second generation GM crops?

Answer 19

First generation crops involve NON TARGETED gene selection, whereas second generation plants are made through genome editing and this allows genome insertion into specific sets of the crop

Question 20

What are the five key advantages of GM crops?

Answer 20

1. Overcomes the pre-zygotes barrier of gene introduction in traditional methods
2. Allows selection of the most ideal traits (no transition of unwanted traits that can occur in selective plant breeding)
3. Faster than plant breeding
4. Increases yields, profitability and farmer convenience
5. Can find the location of new genes

Question 21

What are the three key fears of GM crops?

Answer 21

Allergies
Effects on non target organisms
Trans gene escape

Question 22

Explain trans gene escape and superweeds?

Answer 22

The fear is that GM crops may mate with closely related we’d species in the same area. This may introduced them to herbicide resistant genes, creating superseded populations and making them ore difficult to control. This would essentially create an arms race between the resistant weeds and developing new gem crops

Question 23

What is the allergy risk associated with gm crops?

Answer 23

The fear is that gm crops will introduce allergens to human food, increasing risk to people. However there is currently ZERO evidence of this occurring

Question 24

Where is the greatest risk to humans in terms of GM crops? Include glyphosate in the explanation

Answer 24

In general, the greatest risk is not from the crops themselves, but from their allied technologies. For example, the herbicide glyphosate can be retained on ingested plant parts ( this is readily sprayed because the crops are resistant so distribution is less careful). However this risk is for the fertilisers, not the plant

Question 25

Explain indirect effect on non target organisms of GM crops in the context of monarch butterflies

Answer 25

Monarch butterflies are poisoned by the bt toxin (pesticide) when in high enough concentrations within the plant. This toxin is contained within the plants and only about 1-2 % of plants contain it in high enough concentrations to be toxic to the butterflies. It has been fond that the allied technology of spraying pesticides is more harmful to butterfuly populations

Question 26

The passioura identity states that water-limited crop yield is a function of:

Answer 26

Harvest index

Question 27

What is harvest index?

Answer 27

The pounds of grains(or product) divided by total above ground biomass

Question 28

What is not required in genome editing? Why?

Answer 28

Marker genes are not required because the transgenic dna comes from the same crops

Question 29

What are the three genes involved in genetic engineering?

Answer 29

Promoter
Marker
Desired

Question 30

What is used to cut the DNA from plasmids in genetic engineering?

Answer 30

ENDONUCLEASES (enzymes)

Question 31

What are the three prominent ways of transferring DNA to the desired plant in genetic engineering?

Answer 31

1. Agrobacterium mediated
2. Biological bombardment
3. In vitro selection on selected marker

Question 32

How are transformed cells recovered in genetic engineering?

Answer 32

Via plant-tissue cultivar

Question 33

What products are associated with adverse effects of GM crops, but have nothing to do with the crops themselves?

Answer 33

Glyphosate and Ampa