Cloning Flashcards
A clone
-DNA fragments, cells, tissues or organisms that are genetically identical
How are clones formed in nature?
By asexual reproduction
Molecular cloning
Cloning to make identical genes and useful chemical compounds
Traditional methods of plant cloning
- plant cuttings and grafts
- replanting bulbs and tubers
Plant tissue cultures
growing plants from cells or tissues of a parent plant in a special growth medium
Name at least 3 plant organs for asexual reproduction
runners
bulbs
tubers
leaf plantlets
suckers
A typical plant tissue culture medium
- A glass container with a solid or liquid culture substance
- It contains nutrients and hormones that promote mitosis
Explain what a callus of cells is in a plant tissue culture
- Isolated plant cells from parent plant divide by mitosis
- These form a group of cells called a callus
- With more plant hormones the callus differentiates into roots, stems and leaves
Advantages to making plant tissue cultures
- exact copies with wanted traits
- fast growth to mature plants
- increased quantity of plants possible
- virus-free stock
The first cloned animals, when?
Sea urchins Late 1800s
First reproductively cloned animal, when?
A sheep named Dolly, 1996
How is a reproductively cloned animal made?
- Donor egg cell taken from foster mom
- Nucleus removed
- Cell taken from animal to be cloned
- Nucleus removed and fused with the empty egg cell
- Fused cell divides by mitosis to form embryo
- Embryo placed in foster mothers uterus to develop into cloned individual.
Therapeutic cloning
Cloning to form stem cells
Able to grow into specific tissues
Needed to replace diseased tissues
E.g. skin for burns
E.g. bone marrow transplants for cancer
Embryonic stem cells
Embryonic tissue cells
Can produce more of themselves
Can differentiate into all cell types
Adult stem cells
- Tissue stem cells
- Replace old and damaged cells in adults
- Only certain types
E.g. skin stem
E.g. bone marrow
E.g. Nerve tissue
