Asexual Reproduction

• Asexual reproduction is the production of offspring from one parent
• Clones are organisms that are genetically identical to another organism.
• Fission: a parent cell splits into two, producing genetically identical daughter cells. Unicellular prokaryotes and eukaryotes reproduce by fission
• Fragmentation: when multicellular organisms breaks into fragments, which then regenerate forming daughter cells or organisms.
• Budding: when a small outgrowth develops on the surface of a parent cell and eventually detaches. Nucleus divides by mitosis. Occurs in unicellular organisms and some invertebrate multicellular organisms.
• Parthenogenesis: offspring are produced from unfertilised eggs. The females of the species produce eggs that contain two sets of genetic information. Occurs in many invertebrate species and some vertebrates.
• Spore formation: can be either asexual or sexual. Spores are formed through cell division at the tips of the hyphae and stored in the sporangium. Once the sporangium wall disintegrates, the spores are released and, with favourable conditions, they germinate. Spores are produced by fungi, some protists and prokaryotes.
• Vegetative propagation: asexual reproduction in plants. Includes: tuber, rhizome, stolon, plantlet, bulb, sucker
• Tuber: swollen underground stem that give rise to daughter plants, which arise from buds. Example: potatoes
• Rhizome: horizontal underground stem from which new buds shoot up through the soil and produce daughter plants. Example: ginger, bamboo
• Stolon (runners): horizontal aboveground stems that grow from the parent plant. At various points, the runners give rise to plantlets with their own roots. Once the plantlets are established, the runner die. Example: strawberries
• Plantlets: as well as growing from stolons, plantlets can grow from a leaf surface and then drop to the ground, and then grow into a new plant. Example: mother of thousands
• Bulb: short underground stem surrounded by scales. Each bulb grows into a new plant. Example: onions
• Sucker: a new shoot that arises from a bud on the underground root of the parent plant. Example: blackberries
• Artificial cloning: cloning that occurs due to human interference.
• Cuttings: when a section is taken from the stem, root or leaf of a plant, a new plant identical to the parents can be created.
• Grafting: when the stem of one plant (scion) is attached to the root of another plant (stock) in order for a new organism identical to the scion to be grown. In order for this to happen, the scion and stock must be compatible and at the right stage of development, certain layers must be in contact and the graft union must be moist until the wound has healed.
• Tissue culture (micropropagation): tissues or cells are taken from parent plant and placed in special growing medium under controlled conditions.
• Embryo splitting: embryo cells (produced artificially by the fusion of a sperm and egg nucleus) are separated, with all offspring being genetically identical to each other but not the parents.
• Nuclear transfer: the transfer of a somatic cell's nucleus to an enucleated egg cell. The offspring is genetically identical to the somatic cell donor.
• Gene pool: a measure of all the alleles in a population
• Genetic diversity: the amount of genetic variation that exists between an individuals