cloning and biotechnology Flashcards
1
Q
what is vegetative propagation
A
- production of plant clones from non-reproductive tissues
2
Q
what are 5 natural vegetative propagation methods used by plants
A
- rhizomes
- stolons/runners
- tubers
- bulbs
3
Q
what is the process of tissue culture
A
- cells are removed from the plant that it wanting to be cloned
- removed from stem and root tip as they are stem cells
- cells are sterilised to kill any microorganisms as they would compete for nutrients and effect growth
- cells are placed onto a culture medium with nutrients e.g. glucose for respiration and growth hormones (auxin)
- once cells have divided and grown into a small plant they are removed and placed in soil
4
Q
what is the definition of a clone
A
- usually genetically identical to the parent organism
- formed by a-sexual reproduction and results in clones from mitosis
5
Q
what is the process of natural cloning (vegetative propogation)
A
- a structure forms which develops into a fully differentiated new plant which is a clone of the parent
- this often involves prennating organs which enables the plant to survive adverse conditions
6
Q
how does natural cloning occur in bulbs
A
- leaf bases swell with stored food from photosynthesis
- buds form internally which develop into new shoots and new plants in the next growing seasons
7
Q
how does natural cloning occur in runners
A
- a lateral stem grows away from the parent plant
- roots develop where the runner touches the ground
- the runner eventually withers away after the new plant develops leaving new individual independent
8
Q
how does natural cloning occur in stem tubers
A
- the tip of an underground stem becomes swollen with stored food to form a tuber
- buds form on the tuber and develop to produce new shoots
8
Q
how does natural cloning occur in rhizomes
A
- specialised horizontal stem running underground
- buds develop and form new vertical shoots which become independent plants
8
Q
what is horticulture
A
- art and science of growing plants
9
Q
how is natural cloning used in horticulture
A
- exploited to produce new plants
- increase plant numbers cheaply
- guarntees quality of plants but reduces genetic variation
10
Q
how is sugar cane cloned
A
- short lengths (30cm) are cut and buried in a clear field and covered in a thin layer of soil
11
Q
how is a plant cloned by cutting
A
- use a non-flowered stem
- make an oblique cut in the stem (angled)
- use hormonal rooting powder
- reduce leaves 2 to 4
- keep the cutting well watered
- cover the cutting with a plastic bag for a few days
12
Q
when is micropropagation using tissue culture used
A
- if the plant does not readily produce seeds
- doesn’t respond well to natural cloning
- is very rare
- has been genetically modified or selectively bred with difficulty
- required to be pathogen free
13
Q
what is micropropagation using tissue culture
A
- process of making large numbers of clones from a single parent plant using tissue culture techniques
14
Q
what are the basic principles of micropropagation
A
- take a small sample of the tissue from the plant
- the sample is sterilised usually by immersing it in sterilising agents
- the material removed from the plant is placed in a sterile culture medium containing a balance of plants hormones , the cells proliferate forming a mass of identical cells known as a callus
- the callus is divided up and individual cells are transferred to a new culture medium which stimulates the development of genetically identical plantlets
- the plantlets are potted into compost
- the young plants are planted out to grow and produce a crop
15
Q
what are the pros of micropropagation
A
- allows for the rapid production of large numbers of plants with known genetic make-up which will yield good crops
- culturing meristem tissue produces disease-free plants
- reliably high numbers of rare or endangered plants
16
Q
what are the cons of micropropagation
A
- produces a monoculture susceptible to diseases
- relatively expensive and requires skilled workers
- large numbers of new plants are lost during the process
- vunerable to infection
16
Q
what is cloning in invertebrates
A
- some animals can regenerate entire animals from fragments of the original if they are damaged
- sponges form new identical animals as part of their normal reproductive process
- some insect females can produce offspring without mating
16
Q
what is cloning in vertebrates
A
- monozygotic twins
- early embryos splits into 2 seperate embryos
- although genetically identical they may look different
17
Q
what is artificial twinning in animals
A
- split in early embryo is produced manually, may be split into more than 2
- animal with desirable traits is treated with hormones so the female super ovulates (releasing more mature ova)
- ova may fertilised naturally or by artificial insemination
- alternatively, mature eggs are removed and fertilised by top quality semen in the lab
- usually around day 6 the cells of embryo are split to produce smaller embryos
- each spilt embryo is grown in the lab for a few days than implanted into the mother
18
Q
what is the process of somatic cell nuclear transfer
A
- take the nucleus from an adult somatic cell and transferring it to an enucleated egg which has had the nucleus removed
- a tiny electric shock is used to fuse the egg and nucleus
- stimulated the combined cell to divide and form a clone of adult
19
Q
what are the pros of artificial animal cloning
A
- high yielding form animals to produce many more offspring than normal
- SCNT clones specific animals
- enable rare or endangered animals to reproduce
- enable GM embryos to be replicated giving many embryos from one procedure
20
Q
what are the cons of artificial animal cloning
A
- SCNT is an inefficient process
- many cloned animals fail to produce healthy offspring (many miscarry)
- many cloned animals have a shortened life span
- SCNT has been relatively unsuccessfully so far in increasing populations of rare organisms or bring back extinct species
