GM plants and animals I – GM Food

Question 1

Genetic engineering of foodhas

Answer 1

revolutionized agriculture

Question 2

An example of GM food is

Answer 2

Maize
maize yields have increased four-fold over the last 60 years, and more than half of this increase is due to genetic improvement by artificial selection and selective breeding

Question 3

Maizes original ancestor

Answer 3

Teosinte

Question 4

Selective breeding

Answer 4

select and breed naturally occurring or mutagen-induced variants of crops

Question 5

Worldwide, millions of acres of genetically engineered crops have been planted, particularly herbicide-and pest-resistant soybeans, corn, cotton, and canola; over 50 different transgenic crop varieties are available, including alfalfa, corn, rice, potatoes, tomatoes, tobacco, wheat, and cranberries.

Question 6

Agricultural biotechnology is useful to

Answer 6

■ Improve the growth characteristics and yield of agriculturally valuable crops ■ Increase the nutritional value of crops
■ Provide crop resistance against herbicides (the most widely used application of genetically modified crop plants), insects (insect resistance is the second leading application), viruses, and drought.

Question 7

GM foods are derived from ___________ specifically plants and animals of agricultural importance.

Answer 7

genetically modified organisms (GMOs),

Question 8

GMOs are defined as

Answer 8

organisms whose genomes have been altered in ways that do not occur naturally.

Question 9

GMOs genomes are modified using

Answer 9

recombinant DNA technologies.

Question 10

Genetic engineering allows

Answer 10

one or more genes to be cloned and transferred from one organism to another - either between individuals of the same species or between those of unrelated species.

Question 11

When genes are transferred between unrelated species, the resulting organism is called

Answer 11

transgenic.

Question 12

The term cisgenic is used to describe gene transfers

Answer 12

within a species or from a sexually-compatible species

Question 13

Although many see potential for GM foods - to help address malnutrition in a world with a growing human population and climate change - others question the technology, oppose GM food development, and sometimes resort to violence to stop the introduction of GM varieties

Question 14

Pre-genetic engineering era…

Answer 14

Maize
Wheat
Rice

Question 15

Question 16

the first commercial GM food

Answer 16

The FLAVR SAVR™ tomato

Question 17

The FLAVR SAVR™ tomato

Answer 17

produced in the 1980s by Calgene by silencing the polygalacturonase gene for extended shelf-life.

Question 18

GM food crops

Answer 18

Major crops: maize, soybean, cotton, canola.
Major traits: herbicide and insect resistance.

Question 19

SA 9th largest grower of commercial GM crops.
In SA, only three commercial GM crops – maize, soybean and cotton.

Question 20

GMOs are defined as

Answer 20

organisms whose genomes have been altered in ways that do not occur naturally. Typically, their genomes are modified using recombinant DNA technologies.

Question 21

Genetic engineering allows ________ genes to be cloned and ________ from one organism to another - either between individuals of the same species or between those of unrelated species.

Answer 21

one or more
transferred

Question 22

GM food crops – top five!

Answer 22

Question 23

The most widely planted GM crops – approx. 70%!

Answer 23

Herbicide-Resistant GM Crops

Question 24

Monsanto developed the broad-spectrum herbicide,

Answer 24

Roundup

Question 25

Roundups active ingredient

Answer 25

Glyphosate

Question 26

Glyphosate
(Roundups active ingredient)

Answer 26

is effective at low concentrations, is degraded rapidly in soil and water, and is not toxic to humans

Question 27

However, evidence also suggests that some weeds may be developing resistance to glyphosate,

Answer 27

thereby reducing the effectiveness of glyphosate-tolerant crops.

Question 28

A bacterial gene (epsps)

Answer 28

confers tolerance to the broad-spectrum herbicide glyphosate have been engineered into many crop plants.

Question 29

Second most prevalent GM crops are

Answer 29

Bt crops
(Bacillus thuringiensis)

Question 30

GM crops with insect resistance are mostly

Answer 30

Bt crops

Question 31

Bt crops. Bacillus thuringiensis (Bt)

Answer 31

is group of soil-dwelling bacterial strains that produce crystal (Cry) proteins that are toxic to certain species of insects. These Cry proteins are encoded by the bacterial cry genes. The Cry proteins are toxic to insects

Question 32

Cry proteins specific for

Answer 32

Lepidoptera, Diptera, Hymenoptera and Coleoptera.

Question 33

Insects ingest the crystal toxins,

Answer 33

which are processed by insect proteases into mature toxins that bind to specific receptors on the gut wall, and dissolve the gut membranes to eventually kill the insect.

Question 34

Gut receptors will be bound by only one of more than 200 different Cry proteins

Answer 34

– thus very specific.

Question 35

Cry proteins have been used in conventional formulations for many years – also by ‘organic’ growers.

Question 36

GM crops express Bt genes to produce endogenous crystal proteins,

Answer 36

which will kill specific insect pests, when they feed on such plants.

Question 37

Question 38

To create Bt crops

Answer 38

scientists introduce one or more cloned cry genes into plant cells. The GM crop plants will then manufacture their own Bt Cry proteins, which will kill the target pest species when it eats the plant tissues. Although Bt crops have been successful in reducing crop damage, increasing yields, and reducing the amounts of insecticidal sprays used in agriculture, they are also controversial.

Question 39

Most GM crops have been designed to help farmers increase yields.
However, most are not

Answer 39

consumed directly by humans, but are used as animal feed or as sources of processed food ingredients such as oils, starches, syrups, and sugars.

Question 40

A single bowl (150 g) of golden rice provides

Answer 40

all of the daily requirement of Vit A.

Question 41

Golden rice was designed to produce _______, a Vit A precursor.
Created by:

Answer 41

b-carotene

expressing two transgenes, one from a bacterium and one from maize, in rice.