Asexual Reproduction

1. Asexual Reproduction • The formation of a new individual that has identical genetic information to its parent. • Occurs in all five kingdoms • Monera (bacteria) • Protists (amoeba) • Fungi (mushrooms) • Plants (spider plant) • Animalia (planaria)

2. Binary fission – bacteria do not have nuclei but do have DNA. A bacteria cell undergoes a simplified version of mitosis resulting in 2 new cells having identical DNA as the original cell.

3. Protists – These organisms have a true nucleus. When these single celled organisms undergo mitotic cell division they form two new single celled organisms. An example of this is the paramecium.

4. Fungi – contain many cells • Fragmentation – a small piece ( of the organism simply breaks off and grows into a new fungus. • Budding requires the nucleus to replicate itself. Then a bud forms on the side containing the replicated nucleus. The bud breaks off to form a new individual. Yeast reproduces this way. • Spores – Moulds commonly form a reproductive cell called a spore that is created by mitosis. Moulds produce millions of these cells that when mature form masses of blue, green, or yellow coatings on organic substances.

5. Animals without backbones • Invertebrates commonly reproduce asexually by: • Regeneration – regrowing cut off parts • Budding – part of the organism forms a clump of cells that breaks off and forms a new organism.

6. Plants • Plants continue to grow throughout their whole life (unlike animals). • They have special growing areas called meristems. • As cells from these areas grow, they specialize into roots, leaves or stems. • If meristematic tissue is placed under certain conditions, it will form a new plant. • The new cells formed in this tissue do so by mitosis.

7. Types of Asexual Reproduction in Plants • Cloning - Cuttings taken from a plant will create a new plant with the identical DNA as the original. • New shoots from the roots - Each new shoot is essentially a new plant identical to the original. • New plants from stems – Some plants produce stems called runners. When these specialized stems contact the ground new roots and leaves form creating a new plant. (strawberries) • Grafting – by taking a bud from a tree and attaching it to the stem of a new tree, the bud will grow into a stem. New fruit trees are created in this manner. • Tissue cultures – meristematic cells are placed in a growing media that causes each cell to grow into a new plant. This method is used to create 100’s of new plants.