plant cloning Flashcards
what is biotechnology
the use of living organisms to provide a product or service to humans
what is cloning?
making genetically identical copies or cells of whole organisms
why is cloning an example of biotechnology?
the clones are used by humans for applications such as skin grafting
describe sexual reproduction in plants
- 2 parent plants
- female gamete (ovum) in ovary of flower is fertilised by male gamete (pollen)
- product is seeds which are genetically different
describe asexual reproduction in plants
- 1 parent
- produces genetically identical clones
why is it useful for plants to be able to reproduce sexually and asexually?
- sexual increases genetic variation for natural selection
- asexual is rapid with good yield & reliably increases rare or endangered animals
by what process does asexual reproduction occur?
vegetative propagation
what is vegetative propagation?
growth of new plants from existing vegetative structures (non reproductive tissues eg roots/leaves)
what do plants that undergo vegetative propagation produce?
structures containing meristem
what grows from meristem
new, genetically identical plants
what is meristematic tissue?
regions of plant cells capable of continuous division and growth
what are perennating organs?
storage organs (e.g. tubers, rhizomes and corm), and buds
what are perennating organs important for?
- enables plants to survive adverse conditions
- contain stored food from photosynthesis
- can remain dormant in soil
summarise the steps in cauliflower plant cloning
- sterilise forceps
- clean work surface
- use scalpel to cut mini floret explants and place in petri dish
- place explants in SDICN to sterilise
- swirl every 2-3 mins for 15 mins
- use forceps to strain liquid from SDICN into a beaker
- transfer explant to agar gel
- press stalk into gel and incubate for 10 days
describe how the steps used in cauliflower cloning prevent contamination
- sterilise work surface with ethanol
- use sterilised forceps to place explant in bleach
- pour bleach over forceps to sterilise again
- agar jelly contains bleach
- lids of culture bottle never put directly on work surface
explain the purpose of sucrose in the agar gel
- provides respiratory substrate
- explant has no leaves for photosynthesis
explain the purpose of murashige & skooge medium (minerals) in agar gel
- contains many minerals
- act as nitrogen source (ammonium nitrate)
explain the purpose of agar in agar gel
- gelling agent
- holds substance together
explain the purpose of SDICN in agar gel
- gentle bleach
- does not need to be rinsed
why is it necessary to place explants in a well lit area?
- allows photosynthesis to occur when leaves grow
- glucose reserves are used up and the explant needs to meet nutritional needs through photosynthesis
what are the advantages of using clones to cultivate new plants?
- many clones from one parent
- inexpensive on industrial scale
- multiple copies of endangered plants produced
- crop plants will be uniform in size / appearance
what are the disadvantages of using cloning to cultivate new plants?
- disadvantageous traits from parent will be passed onto clones (eg. susceptibility to genetic disease)
- monoculture farming decreases biodiversity
explain the purpose of kinetin in agar gel
- plant hormones that promote mitosis
- callus of totipotent cells can form
what is a callus
proliferated cells that have formed a mass of identical cells
