Topic 3.5 Cloning Flashcards
Clones
Clones are groups of genetically identical organism, derived from a single original parent cell. Various methods of cloning exist for animals and plants, while humans can also clone organisms tissue artificially.
Animal Cloning: Binary Fission
- The parental organism divides equally into two clones.
- Occurs in flatworms (also used by bacteria and protists)
Animal Cloning: Budding
- Cells split off from parent, generating smaller clones
- Occurs in Hydra, but also common to yeast
Animal Cloning: Fragmentation
- New organisms grow from separates fragments of parent
- Common to Starfish and some species of annelid worm.
Animal Cloning: Parthenogenesis
- Embryos form from an unfertilized (diploid) ova
- Occurs in some species of fish, insect, reptile, amphibian
Animal Cloning Types
- Binary fission
- Budding
- Fragmentation
- Parthenogensis
Human Cloning
Human can also produce clones via natural mechanisms.
- Identical twins (monozygotic) are created when fertilized egg splits in two, forming two identical embryos.
Plant Cloning
Plants have the capacity for negative propagation, whereby small pieces of plant can be induces to grow independently.
A stem cutting is separated portion of a plant stem that is used to regrow a new clone via vegetative propagation.
- This is because adult plants possess totipotent meristematic capable of cellular differentiation.
Artificial Cloning: Embryo Cloning
- Animals can be cloned from an embryo by separating the embryonic cells into groups
- As embryonic stem cells pluripotent, each cell can potentially form a clones offspring
- As this method occurs after random fertilization, it is not possible to control the genetic features of potential clones.
Artificial Cloning: Adult Cloning
- Adults can be clones via the process of somatic cell nuclear transfer (SCNT)
- The nucleus is removed from and adult body cell (diploid) and fused with an enucleated egg cell
- An electric shock stimulates division of the egg cell and the growing embryo is implanted into a surrogate