5.2 Asexual Reproduction Science 9

Definition Asexual Reproduction = only one parent is required to produce offspring (clone = identical genetic copy of its parent) with identical genetic information to each other and to the parent

Five Types Binary Fission Budding Fragmentation Vegetative Reproduction Spore formation

Binary Fission 1. Binary Fission = single parent cell replicates its genetic material and divides into two equal parts -ex: amoeba, bacteria Bacteria undergo binary fisssion Amoeba are unicellular organelles same with bacteria This process is mitosis. IPMAT!

Bacteria- replicate in a very similar manner but Bacteria- replicate in a very similar manner but! Because bacteria don’t have nuclei so they don’t do the conventional mitosis. their DNA can be single stranded or round like a ring…and it replicates and when environmental factors are favourable then the bacteria can reproduce sometimes even as quick as every 20 minutes! And that’s why you can become realy sick quickly Ie strep throat: 2 days entering your body, you can get a very sore throat and fever because the bacteria multiply into millions very very quickly! Antibiotic resistance!

Budding 2. Budding = areas of an individual undergoes repeated mitosis and cell division to develop into an identical organism  forms a “bud” that falls off parent -ex: hydra, sponges, yeast The bud can sometimes detach from the parent and becoming a new individual or it can remain attached. Budding is advantageous for animals like sponges and hydra’s because they are very sessile. They don’t move very much if at all. So they can establish colonies or new colonies if they break away

Fragmentation 3. Fragmentation = fragments that break off organism as a result of injury develop into a clone of its parent -ex: sea star, flatworms If an organism break apart as a result of injury…each fragment can develop into a clone of its parent Ie: sea stars can reproduce asexually from fragments. If one arm detaches from t he parents body, if it contains enough of the parents genetic information. This has lead to the success of sea stars, and has actually impacted the shellfish industry. Sea stars are carnivores they eat oysters and clams but they will eat animal tissue as well Plants can also form through fragmentation because the environment doesn’t change or hasn’t changed. Because there has to be nutrients enough to satisfy the plants needs.

Vegetative Reproduction 4. Vegetative Reproduction = plant stem/root cells divide repeatedly to form structures that develop into a plant identical to the parent -ex: potatoes, strawberries (runners develop roots) Special cells, plant stems and plant roots divide repeatedly to form structures that will eventually develop into a plant identical to the parent. Ex tulip, daffodil, hyacinth, bulbs, strawberry stem Disadvantage: new plants will all grow very close to each other and to the parent. This can lead to competition for soil, nutrients, and light can cause the plants to be less healthy. Benefits: asexual reproduction: benefited for humans: like potatoes, number 1 tuber crop in the world. Originating in S.America. Europeans have taken to It in the 1500’s – really important crop all over the world

Cutting and grafting Humans have assisted nature in helping plants reproduce. Cutting and grafts CUTTING: A plant grower removes a section of the stem, leaf or root and plants the cutting in a special growing medium . Correct amounts of nutrients that enable growth More than 45 plants can reproduce through this method Grafting: plants that cannot grow roots from cuttings, growers use this method -scion- - Apple trees or rose plants. Advantage: produce fruit within 2/3 years because of developed root system which they are attached Can control the eventual size of the plant

Spore Formation 5. Spore Formation = form single-celled spores (= reproductive cell that grows into a new individual by mitosis) -ex: bacteria, fungi, bread mold, mosses, ferns, micro- organisms Spores are very light in weight, spore producers rely on water or wind to carry the spores away from the parent. If conditions are suitable there is enough moisture and the environment is favourable, the individual will grow Many spores have tough outer coating that allows them to survive in harsh conditions like drought or heat until conditions are favourable