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)

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.

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.

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.

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.

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.

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.