Cloning and Biotechnology Flashcards
what is vegetative propagation
Vegetative propagation is a type of asexual reproduction that produces progeny by any vegetative propagule (rhizome, tubers, suckers etc.) without gamete formation and fertilization of male and female gametes
»>produces clones/identical
surviving adverse conditions
name some examples of vegetative propogation
> > stolons- side runners (peg down)
runners- similar to stolons
rhizomes-underground (ginger) pull stem up from underground but any rhizomes left under soil will grow plant again
underground stems- for food storage and reproduction eg)tubers from potato store starch for energy but also can be replanted, bulbs, rhizomes, corms
look up pics of all
what are cuttings and how carried out
take a side shoot (which can eb dipped in rooting powder auxins) and planted into compost and grown. placed plastic bag on top to reduce water loss by excess transpiration
can create open wound for infection in parent
What is grafting? how is it done
graft top part (scion) with one chosen characteristic onto a bottom part (root stock) and wrap and wax to prevent infection and plant will have characteristic of both plants
-eg many apples on one tree of different varieties
what is layering in plants
using peg and stake
The development of roots on a stem while the stem is still attached to the parent plant is called layering. A layer is the rooted stem following detachment (removal) from the parent plant. Some plants propagate naturally by layering, but sometimes plant propagators assist the process.
which tissue of a plant is used in a tissue culture
meristematic tissue- constantly dividing undifferentiated cells that can become any cell
what is tissue culture
aka micropropagation
-cells from meristematic tissue placed on agar plate
-any wool placed on top allows air in for respiring but stops infection
-produces multiple embryos all identical
plantlets are placed in soi
step by step of how tissue culture is carried out
> meristematic tissue taken shoot tip/bud
sterile conditions + sample sterilised
explant placed in sterile culture medium with plant growth hormones such as auxins+cytokinins
mitosis stimulated
cells proliferated - callus formed (mass of identical cells)
callus divided up with forceps- nurtients+hormones produced- differentiation occurs
plantlets form
plantlets potted into compost-grow in greenhouse and harden off
new plant for selling
advantages of tissue culture/plant cloning
-rapid production of large number plants
-known genetic makeup
-disease free/resistant
high yield
-control time of year plants are produced by precisly controlling conditions
-seedless plants/sterile proudced
-overcome problem of growing difficult plants from seeds eg orchid
disadvantages of tissue culture/plant cloning
- all plants have same genetic information so are vulnerable to same disease/ pest
- no new beneficial characteristics will arise as they do by chance naturally (natural selection doesn’t occur)
- no variation means gene pool reduced
what are natural cloning examples in animals
binary fission-splitting apart similar in concept to the mitosis that happens in multicellular organisms
budding-hydra - regrowing heads buds grow on sides of body that develop into genetically identical clones
fragmentation-starfish arm regenerates into new organism
describe difference in reproduction in aphids in seasons
-sexual in autumn and winter
asexual in pathenogenetic female colonies
»>interspecific competition dominates and rapid reprouduction phase is advantageous
how are identical twins formed
Monozygotic
cleavage furrow of fertilised ovum to produce two separate embryos
one sperm and one egg fertilised and undergo mitosis if zygote splits in two they are identical
»shared placenta
how are dizygotic twins formed
2 dif sperm and 2 dif egg genetically distinct
|»_space;separate placenta
how is arteficial embryo splitting carried out
> > high value pedigree animals used as egg and sperm donors eg cattle and sheep
cells from early embryo are separated
each cell can potentially grow into an individual but all will be genetically identical clones
how is an identical clone produced in a pig
1>cells from animal are stored in lab to prevent growth/division
2>the nucleus is extracted from donor cell and fused with an empty egg cell with no nucleus
»»>which came from the unfertilised egg that has had nucleus removed from a sow (which will be the surrogate)
3>fused cells begins dividing normally and matures for a few days
4>embryo placed in uterus of surrogate mother
5> animal born has same DNA as donor animal
pros of animal cloning
- multiplication of animals
- recovery of endangered species
- production of transgenic animals
- replicate animals for research
- produce animals w/ desirable traits
- solution to infertility
cons of animal cloning
- undermines concept of reproduction and family
- playing god
- weakens diversity and ability of adaption
- ethical and moral principles
- concerns about eugenics
- confuses personal identity of clone and psychological development of clone
how was dolly the sheep made
> donor cell taken from sheeps udder with nucleus and egg cell taken from an adult female sheep and nucleus removed so it is ennucleated
these are fused through a process such as electrofusion
the fused cell begins dividing normally
embryo is placed in uterus of surrogate mother
embryo develops into a clone of the sheep who gave the donor nucleus
name 3 advantages of vegetative propagation in agriculture
- higher crop field in a shorter/quicker amount of time
- plants can be grown any time of year regardless of season
- easier to harvest
where is the tissue that is removed coming from for plant clones
what is this tissue sample called
meristematic tissue from axial buds or shoot tips
sample called a explant
what is used to sterilise the plant when preparing to clone
hormones stimulate mitosis which forms a mass of cells called:
ethanol
Callus
compare the equipment and techniques of cuttings with those used for micropropagation
cutting needs less expensive equipment
micropropagation needs more skilled people to do it
what are the advantages of using yeast for biotechnology
no welfare issues involved
- large range of availability and fungi/bacteria
- cheap nutrients
- short life cycle/ but reproduce rapidly
- no rules on genetic engineering
- all they need is food source, low temps and oxygen
