clone definition
groups of cells or organisms that are genetically identical
cloning definition
any procedure that produces genetically identical offspring
examples of cloning
taking cuttings of plants and growing them
steps of growing cuttings
- tear off side shoot (from healthy parent plant, has bud)
- dip into rooting powder (encourages root formation)
- plant in compost/water
- place under glass (more humid and warm, also reduces water loss)
micropropogation
growing plants from small pieces of plant tissue (micro pieces of plant tissue are cultured using nutrient media)
genes and genetic variation in cuttings
identical genes, new cells are formed by mitosis, all offspring are genetically identical, all differences would be due to environment
method of propogating plants in vitro
- explants are scraped from the parent plant
- surface of the explant are sterilised using a disinfectant and sterile water
- sterilised explants are transferred to a sterile petri dish containing sterile nutrient agar (contains nutrients and plant hormones)
- explants with shoots (callus) are transferred to a fresh growth medium that contains plant growth regulators
- plantlets can be transferred to greenhouses (transplanted to normal conditions)
advantages of micropropagation
has many commercial uses:
- plants can be produced with greater yield and quickly
- plants can be grown at any time of year
- plants ae identical (retain desired characterisitc)
- disease-free or resistant plants can be bred
- large numbers can be stored easily
- genetic modifications can be introduced easily
- allow plants that are difficult to grow from seeds to grow (preserve rare plant species)
disadvantages of micropropagation
- trained personnel and sterile lab
all plants are genetically identical so will be vulnerable to the same diseases
(lack of genetic variation=unable to adapt to changing environment)
