Lecture 8

Question 1

Define genetic modification

Answer 1

vitro alteration (lab) of genetic material (DNA or RNA) and the re-introduction of the altered genetic material into a living organism

Question 2

Define genetic engineering

Answer 2

the manipulation of genetic material for practical purposes. Also called recombinant DNA technology.

Question 3

Define genetically modified organism (GMO)

Answer 3

An organism whose genome contains DNA from the same or different species, that has been modified by methods of genetic engineering.

Question 4

Define transgenic plant

Answer 4

genetically modified crops

Question 5

Define transgene

Answer 5

an exogenous gene introduced into the genome of another organism either by artificial techniques

Question 6

Define T-DNA

Answer 6

transferred DNA

Question 7

true or false; plant tissues can grow in culture indefinitely; can grow shoots and roots in culture

Answer 7

true

Question 8

true or false; single cells of plants can grow into whole plants (regenerated)

Answer 8

true

Question 9

Define totipotent

Answer 9

cells that produce all the cell types of a plant

Question 10

true or false; totipotency allows cloning of genetically identical individuals

Answer 10

true

Question 11

Describe the cloning process of a plant using a carrot as an example

Answer 11

1. ) fragments were cultured in nutrient medium
2. ) stirring
3. ) caused single cells to shear off into the liquid
4. ) single cells free in suspension begin to divide
5. ) embyronic plant developed from a cultured single cell
6. ) plantlet cultured in an agar medium
7. ) planted into soil
8. ) adult plant

Question 12

Define adventitious shoots , roots, meristems

Answer 12

arising from an unusual place

Question 13

Define callus cells

Answer 13

undifferentiated, fast growing cells

- many types from soft, white, friable, to hard, green, lumpy

Question 14

Define explant

Answer 14

piece of tissue excised from the plant and cultured in vitro

Question 15

how do new tissue an plants arise from culture

Answer 15

from dedifferentiation, induced morphogenesis and differentiation

Question 16

What are the types of tissue culture

Answer 16

1. ) protoplast fusion (cells without walls)
2. ) meristem culture
3. ) organogenesis
4. ) embryogenesis

Question 17

what is protoplast fusion

Answer 17

• protoplasts isolated from leaf tissue
• remove cell wall
• fused via electroporation or PEG chemicals

Question 18

true or false; fusion can result in incompatibilities and loss of chromosomes

Answer 18

true

Question 19

What does meristem culture mean

Answer 19

(shoot tip culture, bud culture)

- culture of pre-existing meristems —> growth and division

Question 20

What does organogenesis mean

Answer 20

de novo (new formation) of organs from single cells (small clumps of cells); shoots first then regenerate roots

Question 21

What does embryogenesis mean

Answer 21

de novo formation (new formation) of embryos from single cells or small clumps of cells (roots and shoots at the same time); no use of seeds

Question 22

How is organogenesis carried out in African violets

Answer 22

using leaf pieces

Question 23

What is Agrobacterium

Answer 23

full name: Agrobacterium tumifaciens

• causes crown gall disease
• an outgrowth of fast growing, non-differentiated cells
• types of soil bacteria
• infects at wound sites of plant

Question 24

How does Agrobacterium act as a natural genetic engineer

Answer 24

transfers part of its DNA, the T-DNA into plant cells

• introduced any cloned gene into the modified T-DNA and let agrobacterium introduce it into the plants for you

Question 25

When was agrobacterium first modified to become a genetic engineer

Answer 25

1970s - 1980s

Question 26

What is the general process of modifying the agrobacterium plasmid

Answer 26

1. ) restriction enzymes cut
2. ) incorporation of cloned gene via sticky ends (replace the T-DNA gene)
3. ) recombinant plasmid results
4. ) plasmid is introduced to agrobacterium nucleus
5. ) agrobacterium infects desired plant with the desired gene

Question 27

What is the process of making genetically engineered plants

Answer 27

1. ) agrobacterium with recombinant DNA infects plant
2. ) select transgenic callus; callus came from cells along the cut surface into which Agrobacterium has put its DNA containing the foreign gene
3. ) give hormones (eg. auxin: cytokinin) the callus induced to produce shoots and roots to give a plant form what was originally a single cell

Question 28

How to make a transgene contruct

Answer 28

YFG (arrow)
left; promoter sequence
—–> overall trangene
transgene is put into binary vector

Question 29

what is LUC

Answer 29

luciferase gene (reporter gene; acts as a marker)
- attaches to a plant promoter that is expressed most highly in vascular bundles

Question 30

true or false; transgenes are a powerful scientific tool for understanding gene function and basic biological processes

Answer 30

true

Question 31

What are examples of how transgenes are used as a scientific tool for understanding gene function

Answer 31

1. ) ethylene as a ripening hormone (petunias)
2. ) ethylene as a senescence hormone (petunia)
3. ) Cytokinin as an anti senescence hormone
4. ) Apple Myb10 regulating anthocyanin production (eg. apples)