Cloning Flashcards
Describe the process of cloning demonstrated by Dolly the Sheep
- take egg cell from donor gemale and remove nucleus to get an enucleated egg cell
- take adult body cell from the organism you want and remove its nucleus
- take nucleus from the adult body cell and implant it into the enucleated egg cell
- stimulate the cell via a small electric shock and will become a zygote
- zygote will divide by mitosis and form an embryo
- embryo can be implanted in the uterus of surrogate mother and develop into fetus then be born
What kind of adult body cell can be used for cloning?
skin cell
What is a surrogate?
the animal that gives birth to the cloned animal and the fetus develops in their womb
Describe the process of cloning animals
- take a male and a female organism with the most desirable traits
- take sperm from the male and use it to fertilize the egg from the female to form a zygote and develop an embryo
- separate the embryo into smaller ones by mitosis
- implant embryos into multiple surrogate cows to make genetically identical offspring.
What does transgenic mean?
once an organism have DNA from another species
Why might scientists clone transgenic animals?
to genetically engineer them to produce more proteins in their milk for human consumption
eg. insulin in cows
What are the advantages of embryo cloning?
all offsprings identical, faster, more offspring produced, no need for natural mating/intercourse
Describe the process of cuttings
- find the desirable plant to clone
- cut off small part (growing shoot hopefully)
- place cutting in soil along with nutrients + hormones
- cutting will grow into a clone of the original plant
What is micropropagation?
process of cloning plants by tissue culture
Describe the process of micropropagation
- find plant with desirable characteristics to clone
- take explants from the tips of the steps and sterilise them
- place explants in a nutrient medium (agar) and let them grow into calluses in vitro
- transfer the calluses into soil where they can grow into plantlets which can be later transferred to pots to grow into a genetically identical adult plant
What are explants?
small pieces of plant tissue from the tips of the stems
In micropropagation, why do we sterilise the explants?
to remove any micro-organisms that may affect the growth of the plant
What are calluses?
small masses cells grown in agar jelly
What are the advantages of cuttings compared to micropropagation?
cheaper, quicker, less technical expertise and materials needed
What are the advantages of micropropagation?
large numbers of genetically identical plants can be produced rapidly, difficult/dying species can be grown by this method, plants can be produced any time of year, can be stored and developed as required, genetic modifications can be introduced quickly
What does ‘in vitro’ mean?
micropropagated plants are grown outside of the organism and instead in the nutrient medium/agar
What are the nutrients added for growth?
nitrates, phosphates, glucose, sucrose, magnesium
