Cloning and Biotechnology - 6 Flashcards
(54 cards)
What is vegetative propagation
A form of asexual reproduction where new genetically identical individuals develop from non-reproductive tissue
List the 5 types of natural plant cloning methods
Rhizomes
Stolons
Suckers
Tubers
Bulbs
Describe rhizomes
Specialised horizontal underground stems that store food
Can produce new vertical shoots and roots from buds on nodes along the rhizome
Describe stolons
Horizontal stems that grow along the soil surface away from parent plant
Has nodes or stem tips that can root to form a new parent plant
Describe suckers
Shoots that emerge from the shallow root buds of the parent plant
Describe tubers
Form when the tip of a stem becomes swollen with food, with buds in the tuber surface that can develop into new shoots
Describe bulbs
Form when a leaf base becomes swollen with food and the bud inside the bulb can form new shoots
Name 3 methods to artificially clone plants
Stem cuttings
Root cuttings
Leaf cuttings
Explain the process of stem cuttings
Cut a 5-10cm piece from the end of a parent plants stem, using a sharp/sterile tool
Remove the lower leaves, leaving only one leaf at the top
Dip the cut end in rooting powder
Plant the cutting in a suitable growth medium
Place it in warm, moist conditions
Once rooted, transplant the new clone
Explain the process for stem and root cuttings
Root cuttings - Take a section of root and make an angled cut on one end before treating it as you would a stem cutting.
Leaf cuttings - Remove an entire leaf, score the veins, and place it in a growing medium with the scored veins facing down.
Advantages of vegetative propagation
It is fast
Ensures high yield
Cost effective
Maintains crop quality
Allows plants to regenerate each season
Disadvantages of vegetative propagation
Results in a lack of genetic variation
The plants are more susceptible to diseases, pests, climate change
What is micropropagation
A technique for producing many identical plant clones from a single parent plant
Explain the steps in making a tissue culture
Small tissue samples called explants are taken from a parent plant
usually from stems and roots because they have meristem
The explants are sterilised to remove and inhibit growth of contaminants
Reducing risk of widespread infection
The explants are then cultured on a nutrient-rich medium
The medium provides growth hormones and minerals
The cells in each explant divide to form undifferentiated mass of cells called callus
These are transferred to a new medium with specific conditions
Callus can differentiate into plantlets
Fully formed plantlets are moved to a growth medium like soil
Allowing them to develop into mature plants
Why is micropropagation used
Enables the rapid and large-scale propagation of plants that naturally reproduce slowly
Used for producing disease free clones
Can be used to produce seedless plants
Advantages of micropropagation
Produces plants that are genetically identical
Carried out at all times of the year
More space efficient
Rapidly produces a large number of mature plants
Disadvantages of micropropagation
Crops are vulnerable to diseases
May propagate undesirable traits
it is expensive
Explants are vulnerable to infection
How do invertebrates naturally clone
Some undergo regeneration or fragmentation
Forms new genetically identical offspring
How do vertebrates naturally clone
Occurs when an early embryo splits into two genetically identical embryos
Name 2 methods for artificial cloning of animals
Artificial embryo twinning
Somatic cell nuclear transfer
Explain the process of artificial cloning
A female organism is treated with hormones to produce multiple ova
The ova are extracted and fertilised in a petri dish to produce an embryo
Embryo divides into several cells
Each cell is placed into its own petri dish to develop into individual embryos
Embryos are implanted into the uteruses of surrogate mothers for development
Explain the steps in SCNT
A somatic cell nucleus is removed from an adult animal
An ovum of a different female animal of the same species is enucleated
The nucleus from the somatic cell is transferred into the enucleated ovum
Somatic nucleus is fused with the enucleated ovum
Fused cell begins dividing, forming an embryo
This embryo is implanted into the uterus of a surrogate mother
Mother gives birth to a clone of the somatic cell donor
Name 5 uses of animal cloning
Medical research
Conservation
Agriculture
Pharming
Stem cells
Advantages of animal cloning
Ensures the transmission of desirable traits
Enables reproduction of infertile animals
Helps preserve biodiversity
Can rapidly increase population size
Helps medical advancements
